Atari 8-bit family software

This article is an overview of programs available for the Atari 8-bit family of home computers (the 400/800, XL, and XE series). Software was sold both by Atari, Inc. (then Atari Corporation starting in mid-1984) and third parties. Atari also distributed software through the Atari Program Exchange from 1981 to 1984. After APX folded, many titles were picked up by Antic Software.
Programming languages.
Assembly language.
Atari, Inc. published two assemblers. The Atari Assembler Editor cartridge is a friendlier, integrated development environment on using line numbers for editing source code similar to Atari BASIC. The professionally targeted Atari Macro Assembler shipped at a higher price on a copy protected disk without editor or debugger. Third-party assemblers include SynAssembler from Synapse Software and MAE (Macro Assembler Editor) from Eastern House.
Optimized Systems Software published an enhanced disk-based assembler mimicking the structure of Atari's Assembler Editor as EASMD (Editor/Assembler/Debug). It followed that with MAC/65 (first on disk with BUG/65 as a companion product, then as a 16KB bank-switched cartridge). MAC/65 tokenizes lines of code as they are entered and has much faster assembly times than Atari's products.
Dunion's Debugging Tool (or DDT) by Jim Dunion is a machine language debugger originally sold through the Atari Program Exchange. A reduced version is included in the cartridge version of MAC/65. Atari magazine "ANALOG Computing" published the machine language monitor H:BUG as a type-in listing. followed by BBK Monitor.
BASIC.
Atari shipped Atari BASIC with all their machines either as a cartridge or in ROM. It also sold Atari Microsoft BASIC on disk. Optimized Systems Software created a series of enhanced BASICs: BASIC A+, BASIC XL, BASIC XE. BASIC compilers were also available, from 1982's ABC (Monarch Data Systems) to two releases from 1985: Advan BASIC and Turbo BASIC XL.
Pascal.
Atari's own Atari Pascal requires two disk drives and was relegated to the Atari Program Exchange instead of the official product line. Later options were Draper Pascal and Kyan Pascal.
Forth.
Atari 8-bit Forths include fig-Forth, Extended fig-Forth (Atari Program Exchange), ES-Forth, QS Forth, and ValFORTH.
Other.
Action! is an ALGOL 68-like procedural programming language that shipped on cartridge with an integrated compiler and full-screen text editor. The language is designed for quick compile times and to generate efficient 6502 machine code.
Deep Blue C is a port of Ron Cain's Small-C compiler. It was sold through the Atari Program Exchange.
Atari, Inc. published versions of Atari Logo and Atari PILOT on cartridge.
Other Atari 8-bit family languages include Extended WSFN and Inter-LISP/65.
Applications.
Word processors.
Atari, Inc. published the Atari Word Processor in 1981, followed by the more popular AtariWriter cartridge in 1983. Third party options include PaperClip, Letter Perfect, Word Magic, Superscript, Bank Street Writer, "COMPUTE!" magazine's type-in SpeedScript, The Writer's Tool, Muse Software's Super-Text, and relative latecomer The First XLEnt Word Processor in 1986. Cut & Paste from Electronic Arts and Homeword from Sierra On-Line were designed to be simpler to use than other programs.
Two integrated software packages that include word processing are HomePak and Mini Office II. "Antic" compared seven word processors in the February 1987 issue of the magazine.
Games.
Because of graphics superior to that of the Apple II and Atari's home-oriented marketing, the Atari 8-bit computers gained a good reputation for games. "BYTE" in 1981 stated that "for sound and video graphics [they] are hard to beat". Jerry Pournelle wrote in the magazine in 1982, when trying to decide what computer to buy his sons, that "if you're only interested in games, that's the machine to get. It's not all that expensive, either".
"Star Raiders" was Atari's killer app, akin to VisiCalc for the Apple II in its ability to persuade customers to buy the computer. "Antic" in 1986 stated that "it was the first program that showed all of the Atari computer's audio and visual capabilities. It was just a game, yes, but it revolutionized the idea of what a personal computer could be made to do."
A 1984 compendium of reviews used 198 pages for games compared to 167 for all others. It noted the existence of a distinct "graphics look" to native Atari software: "Multiple graphics modes, four directional fine scrolling, colorful modified character-set backgrounds, and, of course, player missile graphics".


GNOME-PPP


MacAmp

MacAmp is an early GUI-based MP3 audio player, first released on April 13, 1997 for the Macintosh by Dmitry Boldyrev of Nullsoft (and later Subband). Its MP3 decoding capability was based on the PlayMedia Systems AMP MPEG-2, Layers 1, 2 and 3 decoder.
By 1999, MacAmp was cited as a "premier MP3 player" and most popular such player for the Macintosh.
In September 1999, a revamped version of MacAmp was released under the name "Macast".


Baal (video game)

Baal is a platform-based shoot 'em up video game published in 1988 by Psygnosis. The player takes on the role of a "Time Warrior" sent into the recesses of hell to recover pieces of "The War Machine", which has been stolen by the evil minion Baal. The game was ported to MS-DOS by Tim Ansell of The Creative Assembly.
Development.
The cover artwork was created by Melvyn Grant.


Slag (video game)

Slag is video game written by Stewart Eastman for the TRS-80 and published by Adventure International in 1980.
Gameplay.
"Slag" is a game in which each player is given a nation, and the object is to totally destroy all other players' industry.
Reception.
J. Mishcon reviewed "Slag" in "The Space Gamer" No. 38. Mishcon commented that "All in all a well balanced game with a lot of very nice options, but a game that heavily depends on your hand-eye coordination to shoot down those missiles. Buy it only if you're really into coordination."


Nginx

Nginx (pronounced "engine X", ), stylized as NGINX, nginx or NginX, is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache. The software was created by Igor Sysoev and publicly released in 2004. Nginx is free and open-source software, released under the terms of the 2-clause BSD license. A large fraction of web servers use NGINX, often as a load balancer.
A company of the same name was founded in 2011 to provide support and "Nginx Plus" paid software. In March 2019, the company was acquired by F5 Networks for $670 million.
, Netcraft estimated that Apache served 24.63% of the million busiest websites, while Nginx served 23.21% and Microsoft is in third place at 6.85% (for some of Netcraft's other stats Nginx is ahead of Apache), while according to W3Techs, Apache is ranked first at 35.0% and Nginx second at 33.0% and Cloudflare Server third at 17.3%.
Popularity.
According to Netcraft's November 2016 Web Server Survey, Nginx was the second-most widely used web server across all "active" sites (18 percent of surveyed sites) and for the top million busiest sites (28 percent of surveyed sites). According to W3Techs, it was used by 38 percent of the top 1 million websites, 50 percent of the top 100,000 websites, and by 57 percent of the top 10,000 websites. According to BuiltWith, it is used on 38 percent of the top 10,000 websites, and its growth within the top 10k, 100k and 1 million segments increased. A 2018 survey of Docker usage found that Nginx was the most commonly deployed technology in Docker containers. In OpenBSD version 5.2 (November 2012), Nginx became part of the OpenBSD base system, providing an alternative to the system's fork of Apache 1.3, which it was intended to replace, but later in version 5.6 (November 2014) it was removed in favor of Apache with OpenBSD's own httpd(8).
Features.
Nginx can be deployed to serve dynamic HTTP content on the network using FastCGI, SCGI handlers for scripts, WSGI application servers or Phusion Passenger modules, and it can serve as a software load balancer.
Nginx uses an asynchronous event-driven approach, rather than threads, to handle requests. Nginx's modular event-driven architecture can provide predictable performance under high loads.
Nginx default configuration file is codice_1, usually found in codice_2, codice_3, or codice_4.
Mail proxy features.
Other features include upgrading executable and configuration without client connections loss, and a module-based architecture with both core and third-party module support.
The paid Plus product includes additional features such as advanced load balancing and access to an expanded suite of metrics for performance monitoring.
Nginx vs Nginx Plus.
There are two versions of Nginx: OSS Nginx and Nginx Plus. Nginx Plus offers additional features not included in OSS Nginx, such as active health checks, session persistence based on cookies, DNS-service-discovery integration, Cache Purging API, AppDynamic, Datalog, Dynatrace New Relic plug-ins, Active-Active HA with config sync, Key-Value Store, on-the-fly with zero downtime updates upstream configurations, and key‑value stores using Nginx Plus API and web application firewall (WAF) dynamic module.
Nginx in comparison to Apache.
Nginx was written with an explicit goal of outperforming the Apache web server. Out of the box, serving static files, Nginx uses much less memory than Apache, and can handle roughly four times as many requests per second. However, this performance boost comes at a cost of decreased flexibility, such as the ability to override systemwide access settings on a per-file basis (Apache accomplishes this with an .htaccess file, while Nginx has no such feature built in).
Nginx also has a reputation of being harder to install and configure than Apache. Formerly, adding third-party modules to Nginx required recompiling the application from source with the modules statically linked. This was partially overcome in version 1.9.11 in February 2016, with the addition of dynamic module loading. However, the modules still must be compiled at the same time as Nginx, and not all modules are compatible with this system; some require the older static linking process.
Nginx is generally considered to be less stable on Windows Server than it is on Linux, while Apache has equal support for both.
Nginx Unit.
Nginx Unit is an open-source web application server, released in 2017 by NGINX, Inc. to target multi-language microservices-based applications. The initial release supported applications written in Go, PHP, and Python. By version 1.11.0, the support was extended to Java, Node.js, Perl, and Ruby applications; other features include dynamic configuration, request routing, and load balancing.
History.
Igor Sysoev began development of Nginx in 2002. Originally, Nginx was developed to solve the C10k problem, and to fill the needs of multiple websites including the Rambler search engine and portal, for which it was serving 500 million requests per day by September 2008.
Nginx Inc. was founded in July 2011 by Sysoev and Maxim Konovalov to provide commercial products and support for the software.
The company's principal place of business is San Francisco, California, while legally incorporated in British Virgin Islands.
In October 2011, Nginx, Inc. raised $3 million from BV Capital, Runa Capital, and MSD Capital, Michael Dell's venture fund.
The company announced commercial support options for companies using Nginx in production. Nginx offered commercial support in February 2012, and paid Nginx Plus subscription in August 2013.Support packages focus on installation, configuration, performance improvement, etc. Support includes proactive notifications about major changes, security patches, updates and patches. Nginx, Inc. also offers consulting services to assist customers in custom configuration or adding additional features.
In October 2013, Nginx, Inc. raised a $10 million series B investment round led by New Enterprise Associates. That round included previous investors, as well as Aaron Levie, CEO and founder of Box.com. In December 2014, Nginx raised a $20 million series B1 round led by New Enterprise Associates, with participation from e.ventures (formerly "BV Capital"), Runa Capital, Index Ventures and Nginx's own CEO Gus Robertson.
In September 2017, Nginx announced an API management tool, NGINX Controller, which would build off of their API Gateway, NGINX Plus. In October 2017, Nginx, Inc. announced general available Nginx Amplify SaaS providing monitoring and analytics capabilities for Nginx.
In June 2018, Nginx, Inc. raised $43 million in Series C Funding in a round led by Goldman Sachs "to Accelerate Application Modernization and Digital Transformation for Enterprises".
On 11 March 2019, F5 Networks acquired Nginx, Inc. for US$670 million.
On 12 December 2019, it was reported that the Moscow offices of Nginx Inc. had been raided by police, and that Sysoev and Konovalov had been detained. The raid was conducted under a search warrant connected to a copyright claim over Nginx by Rambler—which asserts that it owns all rights to the code because it was written while Sysoev was an employee of the company. On 16 December 2019, Russian state lender Sberbank, which owns 46.5 percent of Rambler, called an extraordinary meeting of Rambler's board of directors asking Rambler's management team to request Russian law enforcement agencies cease pursuit of the criminal case, and begin talks with Nginx and with F5.


XBin

XBin, or eXtended Binary, is a file format for saving IBM PC text mode images.
Essentially an extension to the normal raw-image BIN (raw memory copy of text mode video memory) files, it provides an enhanced means for saving console graphics superior to ANSI graphics.
The format was created by Belgian programmer "Tasmaniac" of ACiD, partly in response to the demand for a solution to save images in the BIN image format, which offered no insight as to the size/width of the image. XBin stores its width information internally so that a programmer or user does not need to define this information more than once, an inherent problem with plain BIN files.
XBin also had several notable features above and beyond that of standard text images saved in ANSI format in that it took further advantage of the text mode environment by (optionally) storing alternate palette color information, supporting modified character set fonts and its own simple compression system.


NMS-8250

The Philips NMS-8250, (NMS is short for "New Media Systems") was a professional MSX 2 home computer for the high end market, with two built in floppy disk drives in a "pizza box" configuration. The machine was in fact manufactured by Sanyo and it is basically the MPC-25FS with a different color.
It featured professional video output possibilities, such as SCART for a better picture quality, and a detachable keyboard.


Bumpless Build-up Layer

Bumpless Build-up Layer or BBUL is a processor packaging technology developed by Intel. It is bumpless, because it does not use the usual tiny solder bumps to attach the silicon die to the processor package wires. It has build-up layers, because is grown or built up around the silicon die. The usual way is to manufacture them separately and bond them together.
It was presented in October 2001. It should have been a key component in the 8 GHz and 15 GHz processors that should have been in the market by 2005 and 2007 respectively. Also 20 GHz should have been possible before the year 2010. The BBUL is not needed yet because there is no longer the clock-frequency competition.


Samsung Gear Fit 2

The Samsung Gear Fit2 is a fitness smartwatch made by Samsung Electronics. The product is made in China. Unveiled in June 2016, the Gear Fit2 is the successor to the Samsung Gear Fit released in 2014.
Compared to the Gear Fit the new wristband has an updated design, built-in GPS, and the ability to automatically recognize different fitness activities. The Gear Fit2 features a barometer and heart rate monitor. It is compatible with Android phones running OS 4.4 or later.
Gear Fit 2 Pro.
The successor to the Gear Fit 2 is the Gear Fit2 Pro, released in 2017. It is water-resistant and has improvements related to underwater activity.


PC Today

PC Today (Later "Cyber Trend") was a monthly mobile computing and technology computer magazine published by Sandhills Publishing Company in Lincoln, Nebraska, US.
History and profile.
The article and editorial content focused primarily around mobile and wireless technologies, notebooks, mobile phones, PDAs, Windows, and office and home software. The magazine was renamed "CyberTrend" in 2014, which was distributed to business-class hotels, airline clubs, and fixed-base operators. The magazine also included classified advertising. The magazine ceased publication in July 2017.


Tcsh

tcsh ( “tee-see-shell”, “tee-shell”, or as “tee see ess aitch”, codice_1) is a Unix shell based on and backward compatible with the C shell (codice_2).
Shell.
It is essentially the C shell with programmable command-line completion, command-line editing, and a few other features. Unlike the other common shells, functions cannot be defined in a tcsh script and the user must use aliases instead (as in csh). It is the native root shell for BSD-based systems such as FreeBSD.
tcsh added filename and command completion and command line editing concepts borrowed from the TENEX operating system, which is the source of the “t”. Because it only added functionality and did not change what was there, tcsh remained backward compatible with the original C shell. Though it started as a side branch from the original csh source tree that Bill Joy had created, tcsh is now the main branch for ongoing development.
tcsh is very stable but new releases continue to appear roughly once a year, consisting mostly of minor bug fixes.
On many systems, such as Mac OS X and Red Hat Linux, codice_2 is actually codice_1. Often one of the two files is either a hard link or a symbolic link to the other, so that either name refers to the same improved version of the C shell.
On Debian and some derivatives (including Ubuntu), there are two different packages: codice_2 and codice_1. The former is based on the original BSD version of csh and the latter is the improved tcsh.
History.
The “t” in codice_1 comes from the “T” in TENEX, an operating system which inspired Ken Greer at Carnegie Mellon University, the author of tcsh, with its command-completion feature. Greer began working on his code to implement Tenex-style file name completion in September 1975, finally merging it into the C shell in December 1981. Mike Ellis at Fairchild A.I. Labs added command completion in September 1983. On October 3, 1983, Greer posted source to the net.sources newsgroup.
Significant features.
alias cd 'cd \!* && ls'
if ( "$input" =~ [0-9]* ) then
 echo "the input starts with an integer"
else
 echo "the input does NOT start with an integer"
endif
Deployment.
Early versions of Mac OS X shipped with tcsh as the default shell, but the default for new accounts became bash as of 10.3 then zsh as of 10.15. (tcsh is still provided, and upgrading the OS does not change the shell of any existing accounts). tcsh is the default root shell of FreeBSD (the default user shell is POSIX-based) and its descendants like DragonFly BSD and DesktopBSD.


Polaroid Z340

The Polaroid Z340 is a digital camera that includes a system that can print a photograph on special paper in 45 seconds. It was introduced on November 8, 2011. It is a 14-megapixel digital camera that has a Zink printing system. The camera's printer does not use an ink cartridge. Instead, according to PC World, "cyan, yellow and magenta crystals inside the Zink printing paper are clear until heated by the photo process to create the images." The camera includes basic photo editing software, and can add a variety of decorative borders to the prints.
The Z340 has been designed to resemble the appearance of the Polaroid Spectra cameras popular in the 1980s. It weighs 23 ounces.
Technology writer Nathan Ingraham commented that the "price for novelty is steep" at $299.99. The price has dropped to $199 since then.


Panasonic Lumix DMC-LZ20

Panasonic Lumix DMC-LZ20 is a digital camera by Panasonic Lumix from the year 2012. The highest-resolution pictures it records is 16.1 megapixels, through its 25mm Wide-Angle Lens.


Powernode 9080

The PowerNode 9080 was a dual processor 32-bit Superminicomputer produced by Fort Lauderdale, Florida based electronics company Gould Electronics in the 1980s. Its UTX/32 4.3BSD Berkeley Unix-based operating system was one of the first multi-processor shared memory implementations of Unix, although the processors operated in a Master-Slave configuration with a Mutual Exclusion (MutEx) lock on all Kernel IO resources. Machines could be configured for either single or dual processor operation.
The machine itself was housed in a number of 19 inch rack cabinets and the main CPUs consisted of 18 boards of ECL logic. The resulting system was capable of benchmark performances up to 20 MIPS, a very high rating at the time. The PowerNode systems were a very close relative of Gould's real time computer systems running their proprietary MPX real time operating system. Only about two boards differed between the Unix-running PowerNode machines and the MPX-running real time machines. The most significant of these was the Memory Management board which had virtual memory mapping abilities in the Unix-variant but not in the real-time variant.
A smaller model of the PowerNode was also available in the form of the Gould PowerNode 6032 and 6040 systems which achieved a 7 MIPS performance similar to the contemporary DEC VAX-11/780 and VAX-11/785.
The PowerNode series was replaced by the Gould NP-1 series. When Gould was purchased by Nippon Mining, the computer division was divested on the instructions of the US Government for National Security concerns and became part of Encore Computer.


Disc Filing System

The Disc Filing System (DFS) is a computer file system developed by Acorn Computers, initially as an add-on to the Eurocard-based Acorn System 2.
In 1981, the Education Departments of Western Australia and South Australia announced joint tenders calling for the supply of personal computers to their schools. Acorn's Australian computer distributor, Barson Computers, convinced Joint Managing Directors Hermann Hauser and Chris Curry to allow the soon to be released Acorn BBC Microcomputer to be offered with disk storage as part of the bundle. They agreed on condition that Barson adapted the Acorn DFS from the System 2 without assistance from Acorn as they had no resources available. This required some minor hardware and software changes to make the DFS compatible with the BBC Micro.
Barson won the tenders for both states, with the DFS fitted, a year ahead of the UK. It was this early initiative that resulted in the BBC Micro being more heavily focused on the education market in Australia, with very little penetration of the home computer market until the arrival of the Acorn Electron.
The DFS shipped as a ROM and Disk Controller Chip fitted to the BBC Micro's motherboard. The filing system was of extremely limited functionality and storage capability, using a flat directory structure. Each filename can be up to seven letters long, plus one letter for the directory in which the file is stored.
The DFS is remarkable in that unlike most filing systems, there was no single vendor or implementation. The original DFS was written by Acorn, who continued to maintain their own codebase, but various disc drive vendors wrote their own implementations. Companies who wrote their own DFS implementations included Cumana, Solidisk, Opus and Watford Electronics. The Watford Electronics implementation is notable for supporting 62 files per disc instead of the usual 31, using a non-standard disc format. Beyond that, the Solidisk implementation introduced proprietary "chained" catalogues which alllowed unlimited files per disc (only constrained by the disk size). Other features in third-party implementations included being able to review free space, and built-in codice_1 and codice_2 commands, which were shipped on a utility disc with the original Acorn DFS.
Acorn followed up their original DFS series with the Acorn 1770 DFS, which used the same disc format as the earlier version but added a set of extra commands and supported the improved WD1770 floppy drive controller chip.
Physical format.
DFS conventionally uses one side of a double-density 5¼" floppy disc. Discs are formatted as either 40 or 80 track, giving a capacity of 100 or 200 KB per side (ten 256-byte sectors per track, with FM encoding).
The capacity is limited by the choice of the Intel 8271 controller in the original BBC Micro, which only supports FM encoding, not the MFM encoding which was already in common use by the time of the BBC Micro's launch. FM encoding gives half the recording capacity of MFM for a given physical disc density.
FM and MFM encoding are commonly referred to as "single density" and "double density", although the discs and drives are the same, unlike "high density", which uses different drives and discs.
Double-density 3½" discs can be formatted and used with 1770 DFS (the Intel 8271-based DFS has problems with many 3½" drives), giving the same "single-density" capacity with FM encoding, but this was not originally standard practice. 3½" discs were normally formatted as MFM "double density" using the later Advanced Disc Filing System, as this is present in all Acorn machines supplied with 3½" drives. As of 2009, 3½" drives are more commonly used with BBC Micros than in the past, including use with DFS, due to their greater availability and easier data interchange with more recent computers.
High-density 5¼" and 3½" discs are not supported by DFS.
Single- and double-sided operation.
The DFS does not directly support double-sided discs; instead, the two heads of a double-sided drive are treated as two separate logical drives. The DFS can support up to four volumes, numbered from 0 to 3. Drive 0 is the default with drive 1 representing a second drive attached to the cable. "Drive" 2 referred to the reverse side of drive 0, and "drive" 3 was the reverse of drive 1. There is no support for more than two physical drives.
Due to the installed base of single-sided drives, commercial software was normally provided on single-sided discs, or as "flippy discs" that were manually reversed to access the other side.
40- and 80-track compatibility.
Discs can be formatted using 40 or 80 tracks, using the codice_3 or codice_4 commands, and drives can be either 40 or 80 track. This is the most common compatibility issue for DFS users: 40-track discs were the norm for commercial software distribution, due to the installed base of 40-track drives, but 80-track drives became more common as prices dropped, allowing users to store more data. An 80-track drive will not automatically read 40-track discs.
The disc capacity is stored as a sector count in the catalogue on track zero. Track zero is located in the same place on both 40- and 80-track discs, allowing a disc file system to set the motor stepping accordingly. However, the Intel 8271-based Acorn DFS does not do so, and so dual-format capability was addressed in a number of ways:
Failure to use the correct setting would result in errors from the DFS such as codice_5, or damage to the disc drive by trying to step the heads beyond the physical end of the disc surface.
Switching to 80 tracks did not extend the catalogue in any way, leaving the user prone to running out of filename slots before running out of space on the disc. This situation resulted in a codice_6 error.
File storage.
Filenames.
DFS is case-preserving but not case-sensitive. The prevalence of all-capitals filenames is most likely due to the BBC Micro defaulting to caps lock being enabled after a hard or soft reset. The character set is quite permissive, and all printable characters of 7-bit ASCII are allowed, including spaces, but excluding:
For the sake of portability to third-party DFS implementations, it is best to avoid codice_12 and codice_16 in leaf names.
Quotation marks are allowed, although BBC BASIC requires them to be escaped twice:
A fully qualified filename, or "file specification" ("fsp" for short) contains a colon then the drive number, a dot, then the directory letter, another dot, and the name. For example, a file in the default directory of "drive" 2 called codice_31 would have a complete specification of codice_32. The drive and directory specifiers are both optional.
Directories.
"Directories" in the DFS are single character prefixes on filenames - such as codice_21 in codice_34 - used to group files. The arrangement is flat and a default directory of codice_35 is used instead of a root directory. On requesting a catalogue of the disc (with the codice_36 or codice_37 commands), files in the current directory are shown with no directory prefix in one block, and below that are listed all other files in a second block, with their directory prefixes visible. For example, (from Acorn DFS - third party DFS implementations may vary slightly):
The top seven files are all in the current directory which is codice_35 on drive 0. Below that are all the files in other directories, in this case codice_39, codice_40 and codice_21. An codice_42 after a filename (as with codice_43, above) shows the file is locked against modification or deletion. The first line contains the disc title and the modification count.
The DFS provides a working space, divided up into the directory and the library. The "directory" is the working directory on the current volume, much like the working directory on any other command line system. The "library" is a second, alternative working directory that functions more like "PATH" and had the benefit of being able to be on any volume. Requests to open files with unqualified names, will first be searched for in the working directory; failing this, the library directory will also be searched. The directory and library both default to the same directory.
Disc structure.
The catalogue (file table) occupies the first two disc sectors: one for the names and directories of each file, and a matching sector holding the file locations, sizes and metadata. Eight bytes of each sector are used for each file. With a further eight bytes from each sector reserved for the 12-byte disc title and the volume information, the total number of files on the disc (irrespective of which directory each file is in) is limited to 31. In the interests of saving space, the most significant bit of the directory letter for a file is used as the locked (read-only) flag.
Volume size.
Although physical disks are usually formatted as either 100 KB or 200 KB, DFS supports volume sizes up to 256 KB.
The largest DFS file size allowed is the volume size minus ½ KB for the catalogue, as file sizes are stored as an 18-bit quantity.
File allocation.
The DFS does not support data fragmentation, meaning a file's data must be stored in a single run of consecutive sectors, but free space is prone to becoming fragmented. Random-access file writes fail when the end of the file reaches the beginning of the next, even though there may be free sectors elsewhere on the disc. In such cases the DFS aborts with a codice_44 error. codice_45 is also unable to split a file to fit the available space, but as the failure occurs at the sector allocation stage, the error returned is codice_46.
A codice_47 command is provided to relocate all files on disc to a solid block, placing all the free space after it in a second block. This allows the next file created to fill the disc, but only the last existing file can be extended without being moved. codice_45 deletes any existing file and copies the specified block of memory to wherever there is space on the disc. In contrast the codice_47 command uses program memory as a buffer to relocate the files, overwriting any program and data in memory.
Metadata.
Like the cassette filing system, the Acorn DFS supports the BBC Micro's standard file metadata: load address and execution address, required because Acorn MOS (the operating system used by the BBC Micro) does not support relocation of binary code. A file should be loaded to the address the programmer intended, as the contents may refer to internal locations by absolute addresses. An execution address is also recorded as the entry point is not necessarily at the beginning, or even within the file.
File attributes are limited to a single bit: Locked. When set, an codice_42 appears to the right of the file's name in the catalogue and the file may not be altered, overwritten or deleted.
Dates.
DFS discs do not track any dates (because Acorn MOS prior to version 3 did not maintain a real-time clock) but instead offer a peculiar feature: a modification count. Every time the catalogue is updated, the count increments. The count is shown in parentheses after the title in the first line of the disc catalogue, such as the codice_51 in the catalogue listing shown earlier.
Other features.
The DFS also supports a means to start up disc software based on a key sequence. If the shift key is held while the machine is soft or hard reset, the DFS checks drive 0 for a disc containing a positive boot flag. The boot flag is either 0 (ignore), 1 (load file), 2 (run machine code file) or 3 ("execute" script). If the boot flag is positive, a file called codice_52 is looked for and loaded into memory (1), loaded and executed as machine code (2) or fed into the keyboard buffer (3). Option 3 reads "EXEC" files, text macro files used as primitive shell scripts. These are not true shell scripts but simply a series of keys to be typed, like a recording to play back. Thus, they cannot loop or branch unless they input such code into the BASIC interpreter. As well as being used during a reset, they can be executed at any time with the operating system's codice_53 command. EXEC files are file system independent.
Alternatives.
There was a variant of the DFS called the DNFS, or Disc/Network Filing System, that contained the Econet Network Filing System (NFS), standard Disc Filing System and Tube co-processor support software on a single ROM; this ROM installed two filing systems into the OS at once.
The initial design for the DFS was based around an Intel Corporation FDC 8271 disc drive controller, the immediate predecessor of the 8272 design found in the IBM Personal Computer. The 8271 controller was of limited functionality and obsolete, and later versions of the file system from various vendors including Solidisk, Acorn and Watford Electronics were based on the later WD1770 and WD1772 drive controllers. The 1770 controller quickly became the standard controller in the Acorn range following the advent of ADFS.
The DFS was superseded by the Advanced Disc Filing System (ADFS) which was fully hierarchical and was suitable for running hard drives on the BBC Micro. The ADFS was the default filing system on the BBC Master but most users are likely to have reverted to the DFS for compatibility reasons; ADFS could not read DFS discs. The ADFS was also chosen as the standard filing system for RISC OS.


Big K (magazine)

Big K was a short-lived multi format magazine published by IPC Magazines Ltd during the 1980s. The design of the magazine was very similar in style to their comic strip publications at the time, "2000ad" and "Roy of the Rovers" and seemed to be aimed squarely at the younger computer user.
The March 1985 issue featured the first episode of the digitally created comic strip Shatter, although as this was the last Big K printed, it was also Shatter's only appearance until a run in "Jon Sable: Freelance" from issues #25-30 in June 1985.
External links.
 on the Internet Archive


Nikon D2Xs


Nios embedded processor

Nios was Altera's first configurable 16-bit embedded processor for its FPGA product-line. For new designs, Altera recommends the 32-bit Nios II.


Bill Kincaid

William S. Kincaid (born March 10, 1956) is an American computer engineer and entrepreneur notable for creating the MP3 player SoundJam MP with Jeff Robbin that was eventually bought by Apple and renamed iTunes.
Work.
Robbin and Kincaid worked for Apple in the 1990s as system software engineers on their operating system project Copland; the project was later abandoned. Both left Apple, where Robbin created Conflict Catcher and Kincaid worked at a startup.
After listening to a show on the radio channel NPR, Kincaid created hardware and device driver support for the Diamond Rio line of digital audio players. He then enlisted Jeff Robbin to develop the front-end for an MP3-playing software they named SoundJam MP. Dave Heller completed the core team. The three chose Casady & Greene as distributor, whom Jeff had previously worked with to distribute Conflict Catcher.
The software saw early success in the Mac music player market, competing with Panic's Audion.
In early 2000 Apple was looking to purchase an MP3 player and approached both Casady & Greene (SoundJam) and Panic (Audion). Because Panic was caught up in negotiations with AOL, the meeting never took place. Turning to Casady & Greene, Apple purchased the rights to the SoundJam software in a deal covered by a two-year secrecy clause.
SoundJam MP was renamed iTunes. Jeff, Bill, and Dave became the original developers of the software. All three continue to work at Apple, with Jeff as the current lead developer of iTunes.
In his spare time, he enjoys racing. In a racing profile, he says “A buddy and I wrote Apple's iTunes software and helped develop the iPod and the Apple music store. It wouldn't have happened if I hadn't heard about MP3 on the radio on the way to a race...”


Dell Studio

Dell's Studio brand was a range of laptops and desktops targeted at the mainstream consumer market. The computers sit above Dell's Inspiron and below the XPS consumer lines in price and specifications. They differ from Dell's lower-end Inspiron models by offering slot-loading optical drives, media keys, more cover design options, faster processor options, HDMI and eSATA ports, LED-backlit screens and backlit keyboards.
At launch, the Studio was offered in three models: the Studio 15 and the Studio 17 named after their respective screen size in inches, and the Studio Hybrid, named for its usage of laptop components in the form of an ultra small form factor desktop. If purchased online, many customizable colors, designs and features are available, including a fingerprint scanner in some countries.
On July 29, 2008, Dell introduced the desktop counterpart to the Dell Studio Laptops, the Dell Studio Hybrid PC. A compact desktop legacy-free PC using laptop components, it contains the same slot-loading optical drive as the laptops with the range of connectivity (e.g., number of USB ports) expected of a desktop PC.
On September 24, 2009, Dell released Studio laptops with the option for a mobile Core i7 processor, although Pentium Dual-Core and Core 2 Duo options were still available as lower-end options.
On June 18, 2010, Dell's website stopped selling the Studio Hybrid.
As of May 2011, Dell has discontinued the Studio line of notebooks. The Studio XPS and Studio desktop lines continued on.
Laptops.
Studio 14.
A 14" laptop.
Studio 14z.
A thin-and-light 14" laptop. Lacks an optical drive.
Studio 15.
The Studio 15 is the mainstream model of the Studio laptop line. It has had many options and features that have changed over the years: processors ranging from low-end Pentium Dual Core processors up to quad-core i7 processors. Newly added was the ATI Mobility Radeon 5470 1 GB graphics card. Some models, like the Studio 1537, came in many different colors including, but not limited to orange, red, pink, lime green, black and a range of artistic designs that would be part of the top of the computer and were not user-changeable.
Studio 17.
A 17" laptop.
Studio XPS 13.
A 13.3" laptop that offers a Studio-XPS crossover. Runs on DDR3 memory and uses Intel Core 2 Duo processors. When launched, the Studio XPS 13 was widely acclaimed as the ultimate notebook, offering an irresistible combination of technology, cutting-edge design, performance and luxury style in the increasingly popular market for lighter notebooks. All of its attributes, and its wide success, made it all the more astonishing, if not suspicious, when Dell abruptly discontinued the Studio XPS 13 model, less than a year after its launch, leaving many would-be owners holding their credit cards, and many current owners on guard watching their prized possessions . The wait wasn't long. The latent technical problems, stemming from the notebook's relatively small shell packing a lot of sophisticated hardware, were numerous. Dell's designers simply attempted to pack too much power into the 13-inch model. In the arena of the lightweight notebooks, even one inch can make a difference, so sacrifices must be made. Among the widely reported issues is the overheating in the area of the vent and the video card, whereby the heat spreads to the palm rests and the bottom of the screen. The more serious issue is with the slot-loading optical drive; the device simply does not fit properly into the 13-inch shell. Yet as a result of the model's abrupt discontinuance, users who were in the market for a lightweight Studio XPS 13 model are left with few alternatives, if any. In fact, the only suitable replacement was the Studio XPS 16.
Studio XPS 16.
A larger version of the Studio XPS 13 (16"). It offers an optional Blu-ray optical drive, and has an RGBLED 1080p full HD display (1920×1080), which was widely considered the best display on any laptop in the market. It was available with an Intel Core i7 CPU with two options for video cards, both having 1 GB of video memory: an ATI Mobility Radeon HD 4670 or a 5730.
Desktops.
Studio Hybrid.
A miniature desktop similar to the HP Pavilion Slimline series of desktops and Apple's Mac Mini. It is Dell's most energy-efficient desktop. The desktop is named Studio Hybrid because it uses Intel processors made for laptops as well as a laptop motherboard, memory and a laptop power adapter. The computer itself is enclosed in a plastic interchangeable sleeve which was available in various colors including a $130 premium version made out of bamboo. The machine was based on either a Pentium Dual Core or a Core 2 Duo mobile processor. By default it came with a slot-loading DVD-RW drive but for around $200 your system could be upgraded to a Blu-Ray drive that could also burn DVDs along with the Broadcom Crystal HD card needed to accelerate the video properly (Using Dell Media Direct Software). The board had an integrated Intel X3100 graphics chipset, so while not able to play serious video games, it could be fine for common tasks. When these computers were released in 2008 they initially came with Windows Vista but users were offered the Windows 7 upgrade at no extra cost from Microsoft. The last units to be sold came with Windows 7, but with the maximum ram upgrade of 4gb, could easily run Windows 8 or Windows 10 without a problem. The included stand could be configured to stand up the computer either vertically or horizontally. The appropriate "Hybrid" logo would light up depending on how the machine is orientated.
Studio and Studio Slim.
Using the same case style as Dell's Inspiron 530 and 530s desktops but with a black color, the Studio and Studio Slim desktops are targeted towards consumers looking for a multimedia entertainment desktop.
Studio XPS Desktop.
Combining the Studio's design with the performance of the XPS, the Studio XPS desktop is a full-fledged multimedia center.
Studio One 1909 (Studio One 19).
Released on April 28, 2009 in the United States, the Studio One 19 is a 19-inch all-in-one desktop computer. It is a lower-end alternative to Dell's XPS One 20 and 24. The chassis design is highly reminiscent of Dell's SX2210 21.5 in LCD monitor. The chassis can be customized with five different colors. There is also a touch-screen option.
Issues.
The Studio 15 (older 1535, 1536 and 1537 models) and 17 (1735, 1736 and 1737 models) suffer from problems with the touch sensitive controls where either the eject button or start button for Dell MediaDirect would stay lit for a few minutes after the unit was powered on, rendering the rest of the buttons useless. However, a firmware update for this media panel posted on the Dell Community forums has been reported to fix this issue. Another solution for this issue is to power down the laptop and remove the battery, then holding the power button for 30 seconds to fully discharge all remaining electrical power in the system, draining any residual flea power.
Some users have reported video card problems with the Studio 1555 and Studio 1557, later found to be a faulty driver. Other issues with these models include overheating due to the hard-to-maintain heatsink and fan design, which is located in such a way that a general computer user is unable to access the heatsink and fan for cleaning or other maintenance.
The 1557 and 1558 models were known to have problems with overheating, which was generally linked to 3D gaming or other applications involving 3D graphics. Downloading the latest ATI Catalyst drivers and BIOS updates would help reduce the risk of these problems. The 1557 and 1558 were affected by hard-to-maintain components, which made it hard to clean out blocked heatsink vents or to clean and replace thermal paste due to the combined fan and heatsink design.
There are also several reports of 1557 models freezing up during booting, or having inaccessible hard drives. No clear cause or fix has been put forward by Dell, but it is also likely linked to overheating related to the built-in video card, or software-hardware malfunction related to the built-in ST Microelectronics accelerometer, which is supposed to protect the hard drive in case the laptop is dropped. One proven method to avoid this problem is to remove the ST Microelectronics drivers, thus disabling the hard drive protection function. Keeping the BIOS up to date is also said to reduce the risk.
There are also complaints on the 17" laptops with keyboard and sound malfunctions as well.
However, the issue was found to be a faulty driver. You can easily fix it by updating drivers or reinstalling them. This helped many users, but some users have non-driver issues which are caused by poor manufacturing.


Surface Pro

The Surface Pro is a first generation 2-in-1 detachable of the Microsoft Surface series, designed and manufactured by Microsoft. The device ran a 64-bit version of Windows 8 Pro operating system with a free upgrade possibility to Windows 8.1 Pro, and eventually also Windows 10. Initially announced as Surface for Windows 8 Pro on June 18, 2012, at a Los Angeles event, Microsoft later renamed the device to Surface Pro, and launched it on February 9, 2013.
History.
Microsoft did not take pre-orders for the Surface Pro. It was available for a purchase on February 9, 2013, in the United States, Canada and China, and was released on 23 May 2013, in the United Kingdom and a number of other countries.
Features.
Hardware.
The Surface Pro shares a lot of its design traits with its lower cost counterpart, the original Surface hybrid tablet, announced on the same day. Both have the dark "VaporMg" coating over the same magnesium body and a 10-point multi-touch enabled screen with crack resistant Gorilla Glass. The Wifi is 802.11 a/b/g/n.
However, the resolution on the Surface Pro is higher and is 1920x1080, and the screen has a Wacom digitizer for pen input. Surface Pro runs a dual-core 1.7 GHz Intel Core i5-3317U CPU, with a Turbo Boost frequency of up to 2.6 GHz with a built-in Intel HD Graphics 4000. It has 4 GB of memory and a 64 or 128 GB solid-state drive. Unique to the Surface and Surface Pro is the kickstand which can be flipped out from the back, propping the device up. The kickstand comes out of the devices at a 22 degree angle, the same angle the edges of the device are angled at.
Along the right side of the device, the Surface Pro has a micro-SD card slot on top (with support for cards up to 200 GB), followed by the power port, and near the bottom, a Mini DisplayPort to connect a number of external displays. The bottom of the device (dubbed the "accessory spine") contains the cover port to attach a Touch Cover or Type Cover. In addition to the magnetic attachments, the cover port on the Surface Pro contains a pogo pin connector. Unique to the Surface Pro, compared to the Surface tablet, is the addition of power connectors for compatibility with the Surface Power Cover. The left side of the 2-in-1 contains a full-sized USB 3 port, the volume rocker, and the audio jack. The power button is on the top of the device. On the front and back of the device are two 720p Lifecam cameras, and inside is a 42 Watt-hour battery. Other sensors include an ambient light sensor, accelerometer, gyroscope, and compass.
Software.
Surface Pro originally shipped with Windows 8 Pro, but was upgradeable to Windows 8.1 Pro. The Surface Pro is further capable of upgrading to Windows 10 Pro, which became a free upgrade for users since July 29, 2015.
Accessories.
The 2-in-1 features two types of detachable keyboards: Type Cover and Touch Cover, both with an integrated touchpad. The former is thick and has moving keys for a more traditional typing feel, while the latter is thin and its keys do not move. Both accessories additionally act as a protective screen cover and are sold separately. Later Microsoft introduced the Power Cover (with the Surface Pro 2), which is backwards compatible with the Surface Pro.
Surface Pro is the first device in the Surface family to feature a stylus pen input. "Pro Pen" is based on Wacom digitizer technology. It is integrated with OneNote software which is also included with the Surface Pro and used for note taking and sketches.
The Surface Pro includes a 48-watt power supply with additional 5 W USB port for charging other devices. In early 2016, Microsoft issued a recall for the cable used to connect Surface Pro, Surface Pro 2 and Surface Pro 3 chargers, but not the charger itself, sold before the 15th of July, 2015 due to the risk of electrical fire.
Reception.
Surface Pro received mixed reviews from the computer hardware critics. While most praised the convertible nature of the device, which can be used both as a tablet and a laptop, its design and a precise pressure-sensitive pen, the typical complaints were a short battery life, bulkiness compared to traditional ARM-based tablets and excessive heat and fan noise during periods of heavy load. Other complaints included long response times when the computer was asleep, and even sudden shut downs in the middle of usage.
With the release of the Surface Pro 4 and Surface Book, cooling issues were resolved. Microsoft engineered the computers to dissipate 60% of their heat through the metal body using a combination of heat pipes and copper sinks. The fans only activate under load, allowing the computer to run cold and silent.


ICL 2903 series


Christopher Curry

Christopher Curry (born 28 January 1946 in Cambridge) is the co-founder of Acorn Computers, with Hermann Hauser and Andy Hopper. He became a millionaire as a result of Acorn’s success.
In his early career days, he worked at Pye, Royal Radar Establishment and W.R. Grace Laboratories. Then, in April 1966 he joined Sinclair Radionics where he worked for 13 years. He was involved with their hifi products and their Sinclair C5 electric vehicle. In 1972, he helped Sinclair Radionics to launch its first electronic calculator, the Sinclair Executive. He set up Cambridge Processor Unit Ltd. (CPU) in December 1978. Their first product was the Acorn Microcomputer (later called the System 1).
In 1983, he co-founded Redwood Publishing with Michael Potter and Christopher Ward and they bought the "Acorn User" title. In 1985, he founded General Information Systems Ltd (GIS) and remains the director. In 2012, he announced his latest project for GIS, Care with Canary.
Early life.
Curry went to school initially in St Neots in Cambridgeshire, then later went to the independent Kimbolton School, also in Cambridgeshire. He gained two A levels, in Maths and Physics. He thought about going to university at the University of Southampton, but was keener to be earning some money whilst learning.
Early career.
He joined Pye in Cambridge in 1964. He stayed for a few months, then left for the Royal Radar Establishment in Worcestershire. He worked on the radar for the proposed BAC TSR-2. The RRE had been the site of many technological advances such as the integrated circuit in 1952. He stayed for nine months. He moved to the W.R. Grace Laboratories, run by ITT, and stayed for six months.
Sinclair Radionics.
In April 1966, Curry joined Sinclair Radionics, a company founded by Clive Sinclair in 1961. Curry was to play an important role in getting Sinclair interested in both calculators and computers in his thirteen years with the company.
Curry was at first involved with Sinclair's hifi products, which included amplifiers and speakers, and he also worked on Sinclair's electric vehicle, a project that would turn into the C5 some years later.
In 1972, Sinclair Radionics launched its first electronic calculator, the "Executive", which was considerably smaller than its competitors since it used hearing-aid-sized batteries. Curry and Jim Westwood had discovered that it was possible to exploit persistence in the diode displays and memory and introduced a timer that removed the power from these components for most of the time. This discovery dramatically improved the lasting-power of the batteries.
Until 1976 Sinclair Radionics had enjoyed 15 years of strong turnover and profit growth. However, the company sustained losses related to difficulties with chip supplies for the Black Watch. As a result there were insufficient internal funds available for the final stages of the pocket TV project Sinclair had been working on for some 10 years. In August 1976 the National Enterprise Board (NEB) provided £650,000 in return for 43 per cent stake in Sinclair Radionics. Sinclair did not like sharing control of his company. Thus, he converted a company he had purchased in 1973, Ablesdeal Ltd, into Westminster Mail Order Ltd, which was itself renamed to Sinclair Instrument Ltd. In this way, he maintained control of his most important projects.
Science of Cambridge.
Shortly after the NEB took control Sinclair encouraged Curry to leave Sinclair Radionics to get Sinclair Instruments off the ground. Curry borrowed some money and rented offices at 6 King's Parade, Cambridge. To raise cash, Sinclair Instruments released the Wrist Calculator, designed by John Pemberton, in February 1977. The product was successful, selling 15,000 units.
In July 1977, the company was renamed to "Science of Cambridge Ltd". Around the same time Ian Williamson showed Curry a prototype computer based around a National Semiconductor SC/MP and some parts scavenged from a Sinclair "Cambridge" calculator. Curry was impressed and encouraged Sinclair to adopt this as a product; an agreement was reached with Williamson but no contract was ever signed: Nat Semi had offered to redesign the project so that it used only their components and they also offered to manufacture the boards.
Curry took Nat Semi up on its offer and in June 1978 Science of Cambridge launched a microcomputer kit (marketed as the MK14) based around the National SC/MP chip. Curry wanted to further develop the MK14 but Sinclair was working on the NewBrain. Sinclair's reluctance to develop the MK14 led Curry to consider his options. Throughout the MK14 project he had been discussing it with his friend, physics researcher Hermann Hauser, who had also helped by seeking out advice from the many computer experts on hand in Cambridge University.
Cambridge Processor Unit Ltd.
Curry and Hauser had become increasingly interested in the idea of selling their own computers and so, on 5 December 1978, they set up Cambridge Processor Unit Ltd (CPU). Their first customer was Ace Coin Equipment Ltd, who needed controllers for their fruit machines.
Acorn Computer.
The Acorn Microcomputer (later to be called the System 1) was launched as the first product of a new company, Acorn Computers Ltd, founded in March 1979. Curry said that they "chose the word Acorn because it was going to be an expanding and growth-oriented system".
After becoming a millionaire as a result of Acorn's success with the BBC Micro project, in 1983 Curry co-founded Redwood Publishing with Michael Potter (former publisher of advertising trade weekly Campaign) and Christopher Ward (former editor of Daily Express newspaper). The company bought the Acorn User title.
GIS.
At the time of the Olivetti takeover of Acorn in 1985 Curry founded General Information Systems Ltd (GIS), based on Acorn's Communications Group, and he remains a director.
GIS specialises in Smart Card technologies for access control and electronic money. In 2012 he announced his latest project with GIS, Care with Canary, a wireless sensor system that allows family members to remotely monitor relatives living alone and triggers alerts.


RISCOS Ltd

RISCOS Ltd. (also referred to as ROL) was a limited company engaged in computer software and IT consulting. It licensed the rights to continue the development of and to distribute it for desktop machines (as an upgrade or for new machines) from Element 14 and subsequently Pace Micro Technology. Company founders include developers who formerly worked within Acorn's dealership network. It was established as a nonprofit company. On or before 4 March 2013 3QD Developments acquired RISCOS Ltd's flavour of RISC OS. RISCOS Ltd was dissolved on 14 May 2013.
History.
RISCOS Ltd was formed to continue end-user-focused development of RISC OS after the de-listing of Acorn Computers, following its purchase by Morgan Stanley Dean Witter in order to benefit from the shareholding that Acorn held in ARM Ltd. In March 1999, RISCOS Ltd obtained exclusive rights to develop and sell RISC OS 4 for the desktop market from Element 14. A few weeks later Pace purchased Acorn's Cambridge headquarters and staff for £200,000 and then continued to develop its own, in-house version of RISC OS, primarily for set-top boxes and other embedded devices.
At the time of the company's formation, it was noted that having access to the source code could facilitate removal of the OS's dependence on Acorn's proprietary chips. This simplifies entry to the hardware market by new companies.
On 29 January and 14 May 2013 RISCOS Ltd was listed in the London Gazette: on 14 May 2013 it was struck from the register of companies and dissolved. The rights to all versions of RISC OS previously developed and marketed by RISCOS Ltd were purchased by 3QD Developments Ltd, the maker of VirtualAcorn.
Products.
RISC OS 4.
RISCOS Ltd completed work on "RISC OS 4" and in July 1999 it was released as an upgrade for existing machines, priced at £120. Improvements include support for long filenames, larger disk sizes and partitions, along with a new desktop look.
Work then continued on a system of soft-loaded updated versions of the OS, released under an annual subscription release scheme named "RISC OS Select" in 2002.
In 2004, the company replaced its baseline RISC OS 4.02 product with an updated version of the OS named "RISC OS Adjust". This version of RISC OS was based on version 4.39, or "Select Edition 3 Issue 4", of the company's Select scheme. In the same year, RISCOS Ltd agreed to produce a fully 32-bit-compatible version of RISC OS Adjust for Advantage Six's A9home product. The A9home was released in May 2006 after a 12-month beta-testing process, although the build of Adjust 32, namely RISC OS 4.42, is not feature-complete.
RISC OS Six.
In October 2006, a beta-version of RISC OS Six was made available for download by subscribers to the Select scheme. RISC OS Six represents the next generation of RISCOS Ltd's stream of the operating system. Significant portability, stability and internal structure improvements, including full 26/32-bit neutrality, have laid the foundations for the company's future releases, all of which will be based on version 6. The first product to be based on RISC OS Six will be "Select Edition 4". RISC OS Six is 32-bit-neutral and can be built to run in either 26-bit or 32-bit modes. It runs on the Risc PC and A9home, but it doesn't run on newer-generation hardware such as the Iyonix PC and ARMini, which do not support the 26-bit addressing used on the older Acorn computers and require specific hardware support for the newer ARMv5 and ARMv7 architecture chips that they use.
Licensed emulation.
In 2003, the company reached an agreement with VirtualAcorn to license its OS for use with emulators.
Potential ports.
In 1999, the company announced plans to port the OS to machines such as the Jornada sub-notebook. A number of planned ports did not come to fruition.
Licence dispute.
In November 2002 Castle Technology Ltd released a modified version of Pace's 32-bit RISC OS as "RISC OS 5" for their Iyonix PC, in apparent contravention of the licence agreement that RISCOS Ltd held with Element 14. In July 2003, Castle bought all technology rights to RISC OS from Pace in an attempt to legalise the situation. In January 2004, Castle also took over Tematic Ltd., the company formed by ex-Pace engineers when they were made redundant in March 2003. The result was a long-running and acrimonious dispute between RISCOS Ltd and Castle over licensing, which ultimately led to Castle claiming to terminate RISCOS Ltd's licence to develop, sell and sub-license RISC OS 4. RISCOS Ltd refuted all the claims made and challenged Castle to identify how and from whom they had acquired RISC OS 5. An end to the dispute was signalled when RISCOS Ltd and Castle agreed to work on attempting to merge their development streams and re-unify RISC OS, with Castle's engineers working on key system functionality and RISCOS Ltd on user-facing elements. One of the conditions was that RISCOS Ltd agreed to be renamed RISC OS Developments Ltd. ROL and Castle subsequently agreed to merge and together, this merge nor the name change did happen before the dissolution of RISCOS Ltd.
RISCOS Ltd considered taking legal action in 2008 to prevent RISC OS Open from releasing a RiscPC compatible ROM image.


Flying Saucers (video game)

Flying Saucers is a fixed shooter video game written by Robert Arnstein for the TRS-80 and published by Radio Shack in 1979.
Gameplay.
The object of "Flying Saucers" is to destroy as many alien saucers as possible in the allotted time. There are three types of saucers: large, small, and a super saucer that destroys all visible saucers when shot. There are score penalties for shots that don't hit anything and for letting a saucer escape.
Reception.
Glenn Mai reviewed "Flying Saucers" in "The Space Gamer" No. 39. Mai commented that "Overall, "Flying Saucers" is OK. However, I cannot recommend it because there is a better game with the same name (and price!) on the market, "Air Raid"".


Digital camera modes

Most digital cameras support the ability to choose among a number of configurations, or "modes", for use in various situations. Professional DSLR cameras provide several manual modes; consumer point-and-shoot cameras emphasize automatic modes; amateur prosumer cameras often have a wide variety of both manual and automatic modes.
Manual-enabled modes.
Manual-enabled modes give the photographer control over the various parameters of exposure. There are three exposure parameters – aperture, time (shutter speed), and sensitivity (ISO), and in different modes, these are each set automatically or manually; this gives 23 = 8 possible modes. For a given exposure, this is an underdetermined system, as there are three inputs but only one output. Accordingly, there are many combinations that result in the same exposure – for example, decreasing the aperture by one stop but increasing the exposure time or sensitivity to compensate, and there are various possible algorithms to automatically choose between these.
Most often, ISO is considered separately, being either set manually or set to Auto ISO, and then only aperture and shutter speed need be determined – either determines the other.
The four main modes, sometimes abbreviated "PASM", are:
Together with setting ISO manually or automatically, this (PASM) yields the 4×2 = 8 possible combinations of manual/auto.
Exposure is further controlled in each of the above modes with an independent setting for:
Less commonly seen modes include:
In cases where there is camera discretion (e.g., Auto ISO), different cameras allow different configurations of how decisions are made. For example, , Nikon cameras allow one to set the maximum and minimum ISO sensitivities, and slowest shutter speed that will be used in automatic modes, while Canon cameras will select within the fixed range of ISO 400–ISO 800 in Auto ISO mode. In Nikon cameras, the Auto ISO mode first adjusts the shutter speed, keeping ISO at its minimum desired value, then, when shutter speed reaches the user-defined limit, the ISO is increased, up to the maximum value.
All of the above functions are independent of lens focus and stabilizing methods.
Automatic modes.
In automatic modes the camera determines all aspects of exposure, choosing exposure parameters according to the application within the constraints of correct exposure, including exposure, aperture, focusing, light metering, white balance, and equivalent sensitivity. For example, in portrait mode, the camera would use a wider aperture to render the background out of focus and would seek out and focus on a human face rather than other image content. In the same light conditions, a smaller aperture would be used for a landscape, and recognition of faces would not be enabled for focusing.
Some cameras have tens of modes. Many cameras do not document exactly what their many modes do; for full mastery of the camera, one must experiment with them.
In general:
Secondary modes.
Aside from the main modes which control exposure, there are usually other, secondary settings common to digital cameras.
Drive mode.
"Single" mode will take a single picture each time the shutter button is depressed. "Continuous" or "burst" mode will take multiple photographs in quick succession as long as the shutter button is held down, and is typically used to capture fast-moving subjects such as in sports photography.
Other drive modes commonly available include self-timer, which takes a picture several seconds after the shutter button is pressed; automatic exposure bracketing, used to take multiple photos each with different exposure settings; and remote shutter mode for use with a remote control accessory to trigger the camera at a distance. Some cameras also have an intervalometer mode for time-lapse photography, possibly with the option to automatically create a video from the pictures taken.
Autofocus.
Autofocus (AF) can either activate until a lock is found (single, AF-S) or be continuously active (continuous, AF-C, servo). Single-mode is especially favored for stationary subjects, when focus, once found, should stay fixed, while the continuous mode is used for moving subjects. Some AF systems also include anticipation of the position of moving subjects – Canon calls this "AI servo" (for artificial intelligence) – or can automatically switch between single and continuous depending on whether the subject is moving – Canon calls this "AI focus".
A separate but often related distinction is between and release priority – whether the camera will take a picture when the subject is out of focus or not. In focus priority, the camera will only take a picture when the subject is in focus (as detected by the AF system), while in release priority, the camera will take a picture whenever the shutter is pressed. Release priority is particularly used of fast-moving subjects, which may not be perfectly in focus, or by experienced photographers, who wish to override the camera's judgment of whether the scene is in focus.
These are usually combined: for stationary subjects, AF is set to single (lock when found) and release is set to focus priority, while for moving subjects, AF is set to continuous and release is set to release priority. Manual focus is generally in release priority – AF is neither detected nor set.
Note that these "priority" modes should not be confused with the same word in exposure modes.
Focus priority can also be used for the trap focus trick: to take a picture only when a subject hits a focus point, by using AF to detect focus but not set it.
Back button focus.
In most digital cameras, by default autofocus is only activated (AF-on) when the shutter button is pressed halfway down, which helps to preserve battery life. However, some photographers find that having AF-on and the shutter release on the same button makes it harder to establish the correct focus point, or hold it once the desired point is established. By using a separate shutter and focus button you can lock focus at the same time as shooting without changing exposure, allowing photographers to focus on the subject through the viewfinder.
One technique to make this easier to control is called "back button focus": separating focus from the shutter control button by reassigning the AF-on function to a button on the back of the camera body. Some models of a camera may have a dedicated AF-ON button, and menu options to disable the focus via shutter button half-press. When photographing at golden hour and fighting off sun flare, the back button focus can become an essential tool to use.
Back button focus allows you to benefit from the three main possible focusing modes: manual focus, single focus, and continuous focus. It is a technique favorited by many wildlife photographers due to the unpredictability of animal subjects.
Flash.
Flash modes allow the user to choose between common settings such as: "Fill flash", to always use flash; "Auto flash", which will use flash in low-lit areas; "Red-eye reduction", which may flash once before the actual photo in order to shrink the subject's pupils and reduce red-eye; or, "Flash off", which will never use flash.
Flash can have its own exposure compensation–how brightly it flashes–which allows one to independently adjust the exposure of the foreground (lit by flash) and background (out of flash range).


UNIVAC I

The UNIVAC I (UNIVersal Automatic Computer I) was the first general-purpose electronic digital computer design for business application produced in the United States. It was designed principally by J. Presper Eckert and John Mauchly, the inventors of the ENIAC. Design work was started by their company, Eckert–Mauchly Computer Corporation (EMCC), and was completed after the company had been acquired by Remington Rand (which later became part of Sperry, now Unisys). In the years before successor models of the UNIVAC I appeared, the machine was simply known as "the UNIVAC".
The first Univac was accepted by the United States Census Bureau on March 31, 1951, and was dedicated on June 14 that year. The fifth machine (built for the U.S. Atomic Energy Commission) was used by CBS to predict the result of the 1952 presidential election. With a sample of a mere 5.5% of the voter turnout, it famously predicted an Eisenhower landslide.
History.
Market positioning.
The UNIVAC I was the first American computer designed at the outset for business and administrative use with fast execution of relatively simple arithmetic and data transport operations, as opposed to the complex numerical calculations required of scientific computers. As such, the UNIVAC competed directly against punch-card machines, though the UNIVAC originally could neither read nor punch cards. That shortcoming hindered sales to companies concerned about the high cost of manually converting large quantities of existing data stored on cards. This was corrected by adding offline card processing equipment, the UNIVAC Tape to Card converter, to transfer data between cards and UNIVAC magnetic tapes. However, the early market share of the UNIVAC I was lower than the Remington Rand Company wished.
To promote sales, the company joined with CBS to have UNIVAC I predict the result of the 1952 Presidential election. After it predicted Eisenhower would have a landslide victory over Adlai Stevenson, as opposed to the final Gallup Poll which had predicted that Eisenhower would win the popular vote by 51-49 in a close contest, the CBS crew was so certain that UNIVAC was wrong that they believed it was not working.
As the election continued, it became clear it was correct all along: UNIVAC had predicted Eisenhower would receive 32,915,949 votes and win the Electoral College 438-93, while the final result had Eisenhower receive 34,075,029 votes in a 442-89 Electoral College victory. UNIVAC had come within 3.5% of Eisenhower's popular vote tally, and four votes of his electoral vote total.
After the announcers admitted their sleight of hand, and their reluctance to believe the prediction, the machine became famous. This gave rise to a greater public awareness of computing technology, while computerized predictions were a must-have part of election night broadcasts.
Installations.
The first contracts were with government agencies such as the Census Bureau, the U.S. Air Force, and the U.S. Army Map Service. Contracts were also signed by the ACNielsen Company, and the Prudential Insurance Company. Following the sale of Eckert–Mauchly Computer Corporation to Remington Rand, due to the cost overruns on the project, Remington Rand convinced Nielsen and Prudential to cancel their contracts.
The first sale, to the Census Bureau, was marked with a formal ceremony on March 31, 1951, at the Eckert–Mauchly Division's factory at 3747 Ridge Avenue, Philadelphia. The machine was not actually shipped until the following December, because, as the sole fully set-up model, it was needed for demonstration purposes, and the company was apprehensive about the difficulties of dismantling, transporting, and reassembling the delicate machine. As a result, the first installation was with the second computer, delivered to the Pentagon in June 1952.
UNIVAC installations, 1951–1954
Originally priced at US$159,000, the UNIVAC I rose in price until they were between $1,250,000 and $1,500,000. A total of 46 systems were eventually built and delivered.
The UNIVAC I was too expensive for most universities, and Sperry Rand, unlike companies such as IBM, was not strong enough financially to afford to give many away. However, Sperry Rand donated UNIVAC I systems to Harvard University (1956), the University of Pennsylvania (1957), and Case Institute of Technology in Cleveland, Ohio (1957). The UNIVAC I at Case was still operable in 1965 but had been supplanted by a UNIVAC 1107.
A few UNIVAC I systems stayed in service long after they were made obsolete by advancing technology. The Census Bureau used its two systems until 1963, amounting to 12 and 9 years of service, respectively. Sperry Rand itself used two systems in Buffalo, New York until 1968. The insurance company Life and Casualty of Tennessee used its system until 1970, totaling over 13 years of service.
Technical description.
Major physical features.
UNIVAC I used about 5,000 vacuum tubes, weighed , consumed 125 kW, and could perform about 1,905 operations per second running on a 2.25 MHz clock. The Central Complex alone (i.e. the processor and memory unit) was 4.3 m by 2.4 m by 2.6 m high. The complete system occupied more than 35.5 m² (382 ft²) of floor space.
Main memory details.
The main memory consisted of 1000 words of 12 characters each. When representing numbers, they were written as 11 decimal digits plus sign. The 1000 words of memory consisted of 100 channels of ten-word mercury delay line registers. The input/output buffers were 60 words each, consisting of 12 channels of ten-word mercury delay line registers. There are six channels of ten-word mercury delay line registers as spares. With modified circuitry, seven more channels control the temperature of the seven mercury tanks, and one more channel is used for the 10 word "Y" register. The total of 126 mercury channels is contained in the seven mercury tanks mounted on the backs of sections MT, MV, MX, NT, NV, NX, and GV. Each mercury tank is divided into 18 mercury channels.
Each 10-word mercury delay line channel is made up of three sections:
Instructions and data.
Instructions were six alphanumeric characters, packed two instructions per word. The addition time was 525 microseconds and the multiplication time was 2150 microseconds. A non-standard modification called "Overdrive" did exist, that allowed for three four-character instructions per word under some circumstances. (Ingerman's simulator for the UNIVAC, referenced below, also makes this modification available.)
Digits were represented internally using excess-3 ("XS3") binary-coded decimal (BCD) arithmetic with six bits per digit using the same value as the digits of the alphanumeric character set (and one parity bit per digit for error checking), allowing 11-digit signed magnitude numbers. But with the exception of one or two machine instructions, UNIVAC was considered by programmers to be a decimal machine, not a binary machine, and the binary representation of the characters was irrelevant. If a non-digit character was encountered in a position during an arithmetic operation the machine passed it unchanged to the output, and any carry into the non-digit was lost. (Note, however, that a peculiarity of UNIVAC I's addition/subtraction circuitry was that the "ignore", space, and minus characters were occasionally treated as numeric, with values of –3, –2, and –1, respectively, and the apostrophe, ampersand, and left parenthesis were occasionally treated as numeric, with values 10, 11, and 12.)
Input/output.
Besides the operator's console, the only I/O devices connected to the UNIVAC I were up to 10 UNISERVO tape drives, a Remington Standard electric typewriter and a Tektronix oscilloscope. The UNISERVO was the first commercial computer tape drive commercially sold. It used data density 128 bits per inch (with real transfer rate 7,200 characters per second) on magnetically plated phosphor bronze tapes. The UNISERVO could also read and write UNITYPER created tapes at 20 bits per inch. The UNITYPER was an offline typewriter to tape device, used by programmers and for minor data editing. Backward and forward tape read and write operations were possible on the UNIVAC and were fully overlapped with instruction execution, permitting high system throughput in typical sort/merge data processing applications. Large volumes of data could be submitted as input via magnetic tapes created on offline card to tape system and made as output via a separate offline tape to printer system. The operators console had three columns of decimal coded switches that allowed any of the 1000 memory locations to be displayed on the oscilloscope. Since the mercury delay line memory stored bits in a serial format, a programmer or operator could monitor any memory location continuously and with sufficient patience, decode its contents as displayed on the scope. The on-line typewriter was typically used for announcing program breakpoints, checkpoints, and for memory dumps.
Operations.
A typical UNIVAC I installation had several ancillary devices. There were:
There was no UNIVAC provided operating system. Operators loaded on a UNISERVO a program tape which could be loaded automatically by processor logic. The appropriate source and output data tapes would be mounted and the program started. Results tapes then went to the offline printer or typically for data processing into short term storage to be updated with the next set of data produced on the offline card to tape unit. The mercury delay line memory tank temperature was very closely controlled as the speed of sound in mercury varies with temperature. In the event of a power failure, many hours could elapse before the temperature stabilized.
Reliability.
Eckert and Mauchly were uncertain about the reliability of digital logic circuits and little was known about them at the time. The UNIVAC I was designed with parallel computation circuits and result comparison. In practice, only failing components yielded comparison faults as their circuit designs were very reliable. Tricks were used to manage the reliability of tubes. Prior to use in the machine, large lots of the predominant tube type 25L6 were burned in and carefully tested. Often half of a production lot would be thrown away. Technicians installed a tested and burned-in tube in an easily diagnosed location such as the memory recirculate amplifiers. Then, when aged further, this "golden" tube was sent to stock to be used in a difficult to diagnose logic position. It took about 30 minutes to turn on the computer as all filament power supplies were stepped up to operating value over that time, to reduce in-rush current and thermal stress on the tubes. As a result, uptimes (MTBF) of many days to weeks were obtained on the processor. The UNISERVO did not have vacuum columns but springs and strings to buffer tape from the reels to the capstan. These were a frequent source of failures.


Joe Blade (series)

Joe Blade is the title of a series of budget-price platform games written by Colin Swinbourne and published by Players. All three titles were flick-screen adventures, in which the player controls the title character through a number of rooms, dispatching enemies and rescuing innocent people. The manner of this varies between the three games.
Joe Blade.
The first "Joe Blade" title portrayed Blade as a lone commando sent into an evil mastermind's complex to release a number of diplomats. It was one of the earliest video games to be placed on the "Index" in Germany due to accusations that it "glorified" war and that the villains resembled SS troopers. While the game was still legally obtainable, it effectively banned the game from distribution, as technologies such as the Internet were not available at the time and German publications were not permitted to advertise the titles.
Joe Blade 2.
"Joe Blade 2" took a rather different approach to the first game. Instead of being a soldier, Blade was this time a vigilante taking to the city to rid the streets of criminals, rescuing old-age pensioners along the way. Blade was no longer armed with a gun, and had to jump over villains, just touching them with his feet, to dispatch them. This almost surreal take on the game was in stark contrast to the comparatively more gritty realism of the first installment. The game was also known for being considerably easier than the first title, almost to the point where many players managed to complete the game in one hour-long sitting.
The Spectrum version of the game featured a version of Invade-a-Load featuring Pac Man.
Joe Blade 3.
"Joe Blade 3" returned to the first title's formula, arming Blade with a machine gun. Exclusively released for the ZX Spectrum and Amstrad CPC, it included Commodore 64 instructions in its inlay, but no Commodore 64 version was ever released.
Legacy.
A 1991 Players game, "Prison Riot" plays very similarly to the Joe Blade titles and a hacked version that identifies itself as "Joe Blade 4" has been distributed on the internet.


FiftyThree Pencil


WebNFS

WebNFS is an extension to the Network File System (NFS) for allowing clients to access a file system over the internet using a simplified, firewall-friendly protocol.
WebNFS was developed to give Java applets and other internet enabled applications a way of accessing filesystem services over the internet. While NFS provides applications on Unix with full filesystem semantics, not all of these might be needed in a distributed, read-only web environment. Conversely, access restrictions—such as requiring the use of restricted ports for originating requests—normally used in closed environments are not usually applicable in public distributed environments.
WebNFS makes use of a well known port (port 2049 on both UDP and TCP) thus avoiding the overhead and unpredictability of using the ONC RPC portmap protocol. WebNFS adds public filehandles and multicomponent lookups to the NFS protocol.
WebNFS is specified by a number of RFC-s:
In 2007, Sun Microsystems opensourced its WebNFS implementation. The name has since changed to YANFS (Yet Another NFS) to reflect the expanded scope of the project to include a server side implementation.


DEC Firefly

The Firefly was a shared memory asymmetric multiprocessor workstation, developed by the Systems Research Center, a research organization within Digital Equipment Corporation. The first version built contained up to seven MicroVAX 78032 microprocessors. The cache from each of the microprocessors kept a consistent view of the same main memory using a cache coherency algorithm, the Firefly protocol. The second version of the Firefly used faster CVAX 78034 microprocessors. It was later introduced as a product by DEC as VAX-3520/3540 and called 'Firefox'.
Hardware description.
The Firefly was an asymmetric multiprocessor specialized racked computer as only one of the microprocessors had access to a Q-Bus interface that implemented the I/O subsystem.
Processors.
The Firefly contained a primary processor board and zero, one, two or three secondary processor boards. These processor boards were 8 by 10 inches large. The primary processor board contained a microprocessor, its floating-point coprocessor and cache, and the Q-Bus control logic. The secondary processor boards each contained two microprocessors, their floating-point coprocessors and caches. The original Firefly processor boards used the MicroVAX 78032 microprocessor and MicroVAX 78132 floating-point coprocessor, but later Firefly systems used the faster CVAX 78034 microprocessors, CVAX Floating Point Chips (floating-point coprocessors). The processor boards communicated with each other and the memory via the MBus. The components used in the processor boards of the original Firefly were the same as those originally designed for the MicroVAX II system.
The caches in the Firefly were direct-mapped for simplicity and to support multiprocessing; they used the Firefly protocol to ensure cache coherency. The caches on the MicroVAX processor boards had a capacity of 16 KB (4,096 4-byte lines) and were implemented with eleven 2 KB (4-bit by 4,096-word) SRAMs and twenty transistor–transistor logic (TTL) devices. The cache control logic was implemented with fifteen devices, mostly consisting of programmable array logic (PAL) devices. The caches on CVAX processor boards differed only in the capacity: 64 KB (16,384 4-byte lines) and were implemented with 8 KB (4-bit by 16,384-word) SRAMs.
Memory.
Processors in the Firefly communicated with the main memory through their individual caches and over the MBus. Memory was implemented by one to four memory modules that connect to the MBus. The original Firefly had a master memory module with a capacity of 4 MB and up to three slave memory modules of the same capacity for a memory capacity of 4 to 16 MB. Later Firefly systems used a memory module with a capacity of 32 MB, for a memory capacity of 32 to 128 MB. The memory access time in the original MicroVAX-based Firefly was 400 ns, while the CVAX version had a memory access time of 200 ns.
I/O.
I/O devices were connected to the system via the Q-Bus, whose 22-bit address space was mapped onto the 24-bit memory address space of the Firefly by using mapping registers controlled by the master processor. The devices used direct memory access (DMA) to access the memory though the cache of the main processor. The Firefly's I/O devices were: a monochrome display controller (MDC), a buffered controller for magnetic disk drives, the RQDX3 and an DEQNA Ethernet controller.
While DEC used existing components for most of the I/O system, the display controller was designed specifically for the Firefly by the project's engineers who felt that no existing product met their performance requirements. There were two displayer controllers, one providing color graphics, and the other monochrome graphics. These controllers operated by checking a work queue set up in the memory using DMA, providing fully symmetric access to the display hardware by all processors.
The monochrome display controller (MDC) was contained on a board half as large as the processor boards and was capable of achieving a resolution of 1024 by 768 pixels. It contained a 16-bit 29116 microprocessor clocked at 10 MHz with a 10 KB memory containing 2,048 40-bit words of microinstruction memory. A 1024 by 1024-pixel frame buffer was implemented with VRAMs, with three quarters used to hold the display bitmap with the rest available for the display manager or used to cache fonts.
The 29116 microprocessor periodically checked a work queue set up in the memory using DMA and executed commands from that queue. The commands performed BitBlt operations within the frame buffer, between the system memory and frame buffer and were also used to paint characters from the font cache.
The display hardware also provided an interface for a keyboard and mouse. Sixty times per second, the MDC wrote to the memory the position of the mouse and an unencoded bitmap representing the state of the keyboard. As a result of implementing the MDC as an I/O device, the Firefly supported multiple display controllers in one system connected to multiple monitors.
Software.
Two of the variants of the Firefly used system software called "Topaz", which consisted of multiple components such as the "Taos" operating system that used a microkernel named "the Nub" and the "Trestle" window system. One of the features of Taos was that it supported the Ultrix binary calling interface, allowed existing Ultrix binaries compiled for the MicroVAX run unmodified image on the Firefly. In contrast to Ultrix, Topaz supported processes with multiple threads which could span multiple processors, and the Taos system could run both Ultrix and Topaz applications at the same time. Modula-2+, (a Modula-2 extended language) was used to program both Topaz and its applications.
The Stanford V (operating system) also supported Firefly in a configuration with one CVAX and four Microvax-II CPUs in a BA123 chassis and QVSS?VCB01 graphics.


PWB shell

The PWB shell (also known as the Mashey shell) was a Unix shell.
History.
The PWB shell was a modified (and generally constrained to be upward-compatible) version of the Thompson shell with additional features to increase usability for programming. It was maintained by John Mashey and various others (Dick Haight, Alan Glasser).
PWB/UNIX started with Research Unix 4th Edition in mid-October 1973, and was frequently updated over the next few years, as the PWB department tracked Research Unix changes and added a few features. The PWB shell was released in mid-1975 and remained available through Version 6 Unix-based PWB/UNIX. In Version 7 Unix (1979), the PWB shell was superseded by the Bourne shell. The PWB shell was the standard shell for PWB/UNIX, circa 1975–78., but did not run on any edition of Research Unix, as it required a new system call "udata(2)" that let "login(1)" set login name, login directory ("$s") and TTY ("$t") so "sh(1)" to obtain them.
Notable features.
Several features were introduced in the PWB shell that remain in many later shells. The "if" and "goto" commands were made internal to the shell, and extended to allow "if"-"then"-"else"-"endif", and "switch" and "while" constructs were introduced, as well as "onintr" to ignore interrupts or catch them to perform cleanup. Simple variables could be used, although their names were limited to one letter and some letters were reserved for special purposes, of which some are the precursors of the environment variables found in all Unix systems from Version 7 onward.
For example, The "$s" variable was the ancestor of "$HOME", used to avoid hard-coding pathnames. The "$p" variable was the ancestor of "$PATH", which let users search for commands in their own choice of directories. Unlike most of the UNIX systems of the time, the original PWB/UNIX computer center was shared by multiple programming groups who could not change the contents of /bin or /usr/bin, but wanted to create their own sets of shared commands. In addition, the shell's command-searching was enhanced to allow shell procedures to be invoked like binary commands, i.e., if the shell found a non-binary file marked executable, it would fork another shell instance to read that file as a shell script. Thus people could type "command arguments" rather than "sh pathname/command arguments". All this behavior was packaged as the function "pexec", which was the ancestor of "execvp", to allow any program to invoke commands in the same way as the shell.
The $ character, used previously for identifying arguments to a shell script, became the marker for dereferencing a variable, and could be used to insert a variable's value into a string in double quotes. (In addition to later shells, this feature would also later appear in the Perl and PHP programming languages.)
Descendants.
These features could not overcome the shortcomings of the Thompson shell, and so a new shell was written from scratch by Stephen Bourne. This Bourne shell was incompatible with the Thompson and PWB shells, but included equivalents of most of the PWB shell's features, but done from scratch, rather than incrementally, with much discussion among the various participants. In particular, environment variables and related machinery were designed by Stephen Bourne, John Mashey, and Dennis Ritchie as a general mechanism to replace the earlier, more limited features. After the adoption of the Bourne shell as the standard shell in Version 7 Unix, use of the PWB shell was phased out, although for a while, there was an internal Bell Labs course called "Bourne Shell Programming for Mashey Shell Programmers". (The C shell, developed before the public release of the Bourne shell, also inherited some of the features of the PWB shell.)


TI-57

The TI-57 was a programmable calculator made by Texas Instruments between 1977 and 1982. There were three machines by this name made by TI, the first was the TI-57 with LED display released in September 1977 along the more powerful TI-58 and TI-59. It had 50 program steps and 8 memory registers. Two later versions named TI-57 LCD and TI-57 LCD-II have a LCD display, but were less powerful (ran much slower) and had much less memory: 48 bytes to be allocated between program 'steps' and storage registers.
The TI-57 lacked non-volatile memory, so any programs entered were lost when the calculator was switched off or the battery ran out.
The LED display version of the TI-57 had a rechargeable Nickel-Cadmium battery pack BP7 which contains two AA size batteries and electronics to raise the voltage to the 9V required by the calculator. A popular modification is to power it from a 9V battery and use the battery cover of a LED TI-30 or a part of the dismantled battery pack. This modification provides a better battery life than the original battery pack.
Included, with at least the original version was a book entitled "Making Tracks Into Programming". It was self described as "A step-by-step learning guide to the power, ease and fun of using your TI Programmable 57".
Radio Shack also marketed this calculator, rebranded as the EC-4000.
Programming.
The programming capabilities of the TI-57 were similar to a primitive macro assembler.
Any keystroke could be stored, along with some simple program flow control commands and conditional tests. These included:
GTO (GoTO): Causes program pointer to jump immediately to a Label (0-9) or to a specific program step (00 to 49).
SBR (SuBRoutine): Causes a program to jump to a Label, and on encountering an Inv SBR command, continue executing at the instruction immediately following the original SBR.
DSZ (Decrement and Skip on Zero): Decrements storage register zero, and skips the next instruction if the result is zero. There was also an inverse form, Decrement and Skip if Not Zero.
Tests for equality/inequality could be performed against a value on the display (the "x" register) and a dedicated test register, "t". The result of the test would cause the next instruction to be conditionally skipped.
Programs could be edited by inserting, deleting, or overwriting a program step.
A NOP (No OPeration) function was provided to allow a program step to be ignored.
Due to the hard limit of 50 program steps, use of NOP was infrequent.
The TI-57 used the "one step, one instruction" principle, regardless of whether one instruction required one or up to four keypresses.
Sample program.
The following program generates pseudo-random numbers within the range of 1 to 6.


Sense switch

A sense switch, or program switch, is a switch on the front panel of a computer whose state can be tested by conditional branch instructions in software. Most early computers had several sense switches. They were typically used by the operator to set program options.
On the IBM 1620 there are four switches, and their state can be tested via special forms of the IF-statement offered by the FORTRAN compiler for the IBM 1620. For the IBM 1130 there are sixteen switches matching the sixteen-bit word size of the computer, plus a toggle switch adjacent to the power on/off switch. These bit-switches are more normally used with the computer stopped to specify some memory address to be viewed (via the indicator lights on the front panel), or set. The state of these switches can be determined by a program, and so a running program might modify its behavior depending on the switches, such as change the amount of progress information printed, alter the tactics of a multi-variable optimization attempt, and so on. The IBM 1130 also has an "Interrupt Request" key associated with the console printer, whose pressing might cause a suitably programmed long-running program to type a progress report on the console printer. In the more usual batch job environment, it was pressed by the computer operator to signal the operating system to terminate a running program that had perhaps overrun its allowed time, or commenced misbehavior such as repeatedly printing blank lines.
The front panel of the Data General Eclipse computer has 5 sense switches, 16 address switches, and 5 control switches, as shown (left to right) in the figure at right.
Personal computers replace the function of fixed sense switches with the keyboard and screen user interface.
A typical running application has two modes: either it has nothing to do and awaits some user action, or, some action is in progress that will take a long time to complete. If a program does not regularly test the state of sense switches during a long calculation, they are ineffective at changing the program's operation.