Dick Smith Super-80 Computer

The Dick Smith Super-80 was a Zilog Z80 based kit computer developed as a joint venture between Electronics Australia magazine and Dick Smith Electronics. It was presented as a series of construction articles in Electronics Australia magazine's August, September and October 1981 issues.
Electronics Australia had published a number of computer projects before the Super-80, including the EDUC-8 in 1974, the Mini Scamp and the DREAM 6800 Video Computer.
The computer was sold as a "short form" kit for A$289.50. For this, the purchaser received the computer PCB, an assembly manual (a copy of the construction articles from Electronics Australia) and basic components, including 16kB of RAM and a 2kB EPROM containing a machine code monitor program. The technical manual and power transformer were sold separately, as were a kit of I.C. sockets, a BASIC interpreter program and from mid-1982 onwards, a metal case to house the computer.
The computer proved to be a popular construction project, with an advertisement in November 1982 claiming: "Over 2000 sold."
The popularity of the Super-80 led to a small industry growing up around addressing the shortcomings of the original computer - especially the black and white, 32 × 16 character, upper case only video display.
The original name of the computer was "Nova-80", but it was changed at the last minute to avoid "possible legal ramifications".
Technical description.
The Super-80 was based on the Zilog Z80 8-bit microprocessor. As standard, it had 16 kB of dynamic RAM in the form of eight 4116 RAM chips. RAM could be expanded to 32 kB or 48 kB through the addition of rows of eight 4116 RAM chips.
The computer was assembled on a single double-sided printed circuit board. The board was supplied in a light cardboard sleeve that appeared to be an LP record sleeve, having the words "Dick Smith Super 80 Microcomputer Kit Printed Circuit Board" and the part number "Cat H-8402" printed along the spine.
To keep the price of the computer and the component count down, a novel technique was used to implement the video display. Instead of an expensive video display controller chip with dedicated memory, the Super-80 used discrete TTL logic to implement the video display and 512 bytes of system RAM was shared between the video display and the CPU. Fifty times per second, the CPU was turned off for around 10 ms by asserting the Z80 BUSREQ (DMA) pin. The video display circuitry would then read from the shared RAM while it refreshed the image on the screen. In addition to a 50% degradation in processor performance, this meant that it was not possible to perform any accurate timing in software, since the programmer had no control over when the next video display refresh cycle would occur. The video display could be switched off under software control for greater processing speed, or when accurate software timing was required. The most common situation in which that occurred was when the built-in cassette interface was being used. The location of the 512 bytes of video memory was normally at the top of the available RAM, but could be changed by writing to an I/O port.
The keyboard was part of the main computer PCB, but before assembly, the constructor could opt to cut the keyboard section of the printed circuit board off and connect it to the main board with ribbon cable. The keyboard was wired as an 8 × 8 matrix and connected to the computer via the two 8-bit ports of a Z80 PIO chip. Pressing the keys <CTRL>, <C> and <4> at the same time generated an interrupt that would perform a "warm start" of the monitor program. The keyboard 'read' routine supplied in ROM was "negative edge triggered" and would block while a key was down. As a result, most action games incorporated their own keyboard driver.
The standard computer had no serial or parallel I/O as such, relying on the optional S-100 bus interface for I/O and expansion. A 10-pin connector at the back of the board was labeled "PORT" and had power, as well as a pair of digital outputs and two available digital input lines. The connector was for a future RS-232 / 20 mA current loop serial interface, but that was never implemented.
Mass storage was available in the form of a cassette tape interface running at 300 baud. Accessing the cassette interface required the video display to be switched off, so an LED was provided to show activity during a tape load or save operation. The LED would change state each time a 256-byte block of data was successfully transferred.
The Z80 interrupt line was connected to the keyboard PIO and the "Non Maskable Interrupt" line was not connected.
Software.
The Super-80 came with a 2kB machine code monitor program in ROM.
A BASIC interpreter could be purchased either on cassette tape or on a set of three 4kB EPROMs. The first 4kB BASIC EPROM replaced the 2kB monitor EPROM supplied with the computer and contained the first 2kB of BASIC, plus the monitor program. The BASIC interpreter was based on Tiny BASIC rewritten and modified by Ron Harris.
In its November 1981 edition (p93), Electronics Australia announced a programming competition with the chance to win one of two dot matrix printers. EA later compiled the better programs submitted by readers into a book called "Software for the Super-80 Computer".
Modifications.
Many Super-80 owners chose to modify their machines to address the limitations of the original machine.
The El Graphix kit added the ability to display lower case characters and "chunky" graphics.
The Printer Interface was an S-100 Bus card giving the Super-80 a Centronics parallel printer port.
The VDU Expansion Board (VDUEB) was an enhanced video display board for the Super-80 developed by Microcomputer Engineering (MCE). The VDUEB gave the Super-80 an 80×25 video display with limited graphics capabilities. It was based on a 6845 CRTC I.C. and had its own 2kB of video RAM and 2kB of character generator RAM. Installation of the VDUEB board was a one-way process, as it required major modifications to the Super-80 printed circuit board including cutting of tracks and soldering in many wire links between various parts of the board. The VDUEB was then connected via three I.C. sockets formerly occupied by the original video display circuitry. Removal of the original DMA based video display effectively doubled the performance of the computer, since the CPU was no longer being disabled 50 times per second for video display refreshes. The board gave the Super-80 similar video display capabilities to the Applied Technology Microbee computer, released about six months after the Super-80. This led to many Microbee games being ported to the VDUEB equipped Super-80. The VDUEB proved to be a popular modification, with a users' group forming for owners of VDUEB equipped computers - The "Super-80 VDUEB Users' Club".
The Universal Floppy Disk Controller (UFDC) was an add-on floppy disk interface developed by Microcomputer Engineering (MCE). The UFDC was based on the Western Digital WD2793 floppy disk controller chip and had a Z80 DMA controller on board. The most popular disk format was 5" (133 mm) 80 track, double sided, double density using a Mitsubishi floppy drive mechanism. This gave a formatted disk capacity of 800kB. The UFDC's use of DMA required the VDUEB upgrade to be present. To install the disk controller, the Z80 CPU was removed from the main computer board and installed on the UFDC board. The UFDC then piggybacked on the socket vacated by the CPU. This meant that in theory, the UFDC could be used with almost any Z80 based system, provided there was enough physical space above the CPU. The UFDC used a primitive track based disk operating system called "Super-80 DOS", however a CP/M BIOS later became available.
The MXB-1 Memory Expansion Board was designed by a member of the VDUEB Users' Club. The MXB-1 contained space for extra EPROMs, an optional battery backed real time clock, a centronics compatible printer interface and address decoding for up to 192kB of RAM. The extra RAM was installed by replacing the standard 4116 16k × 1 bit RAM chips with 4164 64k × 1 bit RAM chips. The CPU's 64kB address limit was worked around through bank switching. The MXB-1 was mostly of benefit to users running the CP/M disk operating system, since CP/M could then have a full 64kB of RAM for programs, with up to 128kB being used as a small RAM disk.
The El Graphix "X-RAM" board provided up to 16K of battery backed CMOS RAM or EPROM. Several X-RAM boards could be piggybacked allowing each to be port selected as independent 16K banks of memory. This memory took the form of 8 x 2K 24pin sockets which accepted either 2016 CMOS RAM or 2716 EPROMS. As the system ROM shared part of the address range taken up by the X-RAM board the system ROM could be copied into CMOS RAM on the fly and modified as required to actively add or modify custom functions into the operating system.


List of transistorized computers

This is a list of transistorized computers, which were digital computers that used discrete transistors as their primary logic elements. Discrete transistors were a feature of logic design for computers from about 1960, when reliable transistors became economically available, until monolithic integrated circuits displaced them in the 1970s. The list is organized by operational date or delivery year to customers. Computers announced, but never completed, are not included. Some very early "transistor" computers may still have included vacuum tubes in the power supply or for auxiliary functions.
1960s.
1964.
[[File:SDS 930.jpg|right|thumb|SDS 930]]
1965.
[[File:NCR-315, pt. 1 (2231627349).jpg|right|thumb|NCR 315]]
1966.
[[File:Bundesarchiv B 145 Bild-F031433-0011, Aachen, Technische Hochschule, Rechenzentrum.jpg|right|thumb|CDC 6400]]
References.
[[Category:Transistorized computers]]


Tac (Unix)


Commodore 8280

The Commodore 8280 is a dual 8" floppy disk drive for Commodore International computers. It uses a wide rectangular steel case form similar to that of the Commodore 4040, and uses the parallel IEEE-488 interface common to Commodore PET/CBM computers.
The 8280 replaced the earlier 806x series 8" drives and switched to half-height drives. Like the 8061/62 units, the 8280 supports IBM 3740 disks. However, instead of 500k group code recording (GCR) format used by other Commodore drives, it uses MFM as its native disk recording format, the only 8-bit Commodore drive to do so apart from the 1581. Contrary to the 8061/62, the drive ROM has the capability for formatting disks and verifying them, eliminating the need for external utility disk for these operations. The manual contains also a simple BASIC listing of a program to read sectors from IBM 3470 disks.


HP 35s

The HP 35s (F2215A) is a Hewlett-Packard non-graphing programmable scientific calculator. Although it is a successor to the HP 33s, it was introduced to commemorate the 35th anniversary of the HP-35, Hewlett-Packard's first pocket calculator (and the world's first pocket scientific calculator). HP also released a limited production anniversary edition with shiny black overlay and engraving "Celebrating 35 years".
Features.
The HP 35s uses either Reverse Polish Notation (RPN) or algebraic infix notation as input.
Other features of the HP 35s include:
The HP 35s has been given a retro look reminiscent of classic HP calculators from the 1970s to the 1990s. However, it provides far more functions, processing power, and memory than most of those earlier models.
The physical appearance and keyboard layout of the HP 35s is very different than that of its immediate predecessor, the HP 33s, but the two calculators are functionally very similar. The primary differences are:
HP has released a free-of-charge 35s emulator for the Windows operating system (and Wine). This was previously only available to teachers for classroom demonstration purposes.
Construction.
The HP 35s was designed by Hewlett-Packard in conjunction with Kinpo Electronics of Taiwan, which manufactures the calculator for HP in mainland China.
According to HP, the calculator has been engineered for heavy-duty professional use, and has been tested under extreme environmental conditions. It is built using 25 screws for rigidity and ease of maintenance.
The case features many design elements from 1970s HP calculators such as the ground-breaking HP-65, including a black case with silver-striped curved sides, slope-fronted keys, and gold and blue shift keys. The faceplate is metal, bonded to the plastic case. The key legends are printed, rather than the double-shot moulding used in the vintage models.
The calculator is powered by two CR2032 button cells, which it is advised to replace one at a time, to avoid memory loss.
It was initially supplied with a hard zippered clamshell case with a pocket for notes, and a printed manual, but this was later changed to a slipcase made of vinyl-covered cardboard with elastic sides and velvet lining, and a CD-ROM containing a PDF manual.
The calculator is entirely self-contained; there is no facility for upgrading the firmware, nor for loading/saving programs and data.
Reception.
The build quality and industrial design of the 35s has been welcomed by reviewers as a return to the best HP professional calculator traditions, in contrast to their more recent advanced calculators which were seen as feature-packed and heavily styled for the student market, but in some cases poorly designed and built. Particular mention has been made of the traditional HP feel of the keyboard with a big key back in its traditional place. Shortcomings which have been identified include the lack of any facility for communication with a computer (for loading and saving programs and data), and sluggish performance.
Response to the calculator's logic has been mixed. The increase in addressable registers and introduction of program line-number addressing have been seen as a big improvement over the 33s. While welcoming the improved handling of complex numbers compared to the 33s, the incomplete support for them has been criticised. Working with hexadecimal and other non-decimal bases has been criticised as requiring excessive and unintuitive keystrokes. Several firmware bugs have also been reported, which have not yet been fixed.
The 35s's lack of communication abilities makes it acceptable for use in some professional examinations where more powerful calculators would not be. For example, in the US, it is the most powerful programmable calculator approved for use in the Fundamentals of Engineering (FE) and Principles and Practice of Engineering (PE) examinations.
Feature details.
Entry modes.
The 35s supports both RPN and algebraic entry modes. Like most HP calculators, it defaults to RPN. The entry mode can be easily changed by the user. An annunciator on the display indicates the current entry mode.
In RPN mode, it uses a four-level stack, as have all HP's non-graphing RPN calculators since the earliest days. In contrast to the usual computer-science terminology, RPN calculators such as this refer to the operational end of the stack as the "bottom" and the far end as the "top". The stack levels are named X (the bottom), Y, Z, and T (the top); they have no connection with the variables of the same names. Level X appears on the lower line of the display and level Y on the upper line. Each stack level can contain any of the data types supported by the machine: real number, complex number, or vector. Various functions are provided for manipulating the stack, such as and to roll, to swap X and Y, to recall the last-used X value, and to swap X and a named variable.
Algebraic mode works by the user entering an expression, then pressing to have it evaluated. The expression appears on the upper line of the display, the result on the lower line. The expression can be edited using the arrow and backspace keys, and re-evaluated as desired.
Units and fractions.
In keeping with the calculator's retro theme, conversions between Imperial/US units and the equivalent standard metric units feature prominently on the 35s's keypad. To facilitate those who still use traditional units, and for other uses, the calculator also allows the entry of values as mixed fractions and the display of values as mixed fractions.
Entry of mixed fractions involves using decimal points to separate the parts. For example, the sequence converts inches to 10.0 cm (approximately).
The calculator may be set to automatically display values as mixed fractions by toggling the key. The maximum denominator may be specified using the function. Numbered flags may be set to specify which of three denominator systems is to be used: most precise denominator, factors of the maximum (for example 2, 4, 8, 16, when the maximum is 16), or a fixed denominator. Two small arrow symbols on the display indicate if the actual value is slightly above or below that displayed. There are no functions to directly extract the parts of the displayed fraction.
Complex numbers.
Previous (and other current) HP calculators have handled complex numbers in a variety of ways. In the HP 33s, complex numbers were stored as two separate values, and the "complex" modifier was used to indicate that an operation was to treat the stack as containing complex numbers. For example, adding and involved the following keystrokes: , which used up all four stack levels.
The 35s stores complex numbers as single values, which can then be operated on in the standard ways. The above example of adding and then becomes: .
On the 35s, the number of functions able to handle complex numbers is limited and somewhat arbitrary. For example, directly taking the square root of a negative real number results in an error message instead of a complex number. This is strictly correct given that a nonnegative real number "a" has a unique nonnegative square root and this is called the "principal square root" which is denoted by . The symbol √ is called the "radical sign" or "radix". For example, the principal square root of 9 is 3, which is denoted by = 3, because and 3 is nonnegative. However raising x to the power of 0.5 using the key works if the number is entered as a real number with a complex part equal to zero. Inverse and hyperbolic trigonometry functions cannot be used with complex numbers. Base-e (natural) logarithms and exponentiation can be used, but not base-10. However, workarounds exist for many of those limitations.
Complex numbers can be entered in either rectangular form (using the key) or polar form (using the key), and displayed in either form regardless of how they were entered. They can be decomposed using the (radius "r") and (angle "Θ") functions. There are no functions for extracting real and imaginary parts, though that can be worked around, using the formulas and .
Vectors.
The 35s provides facilities for handling vectors of up to three real-number elements. A vector may be stored on the stack, or in any variable, as a single value, and processed by various functions. It is entered by the user starting with a square bracket , then the element values separated by commas . Vectors can be added, subtracted, multiplied and divided by scalars. Two vectors of similar dimensions may be added and subtracted, and multiplied to give their dot product. The function will return a vector's magnitude. A cross-product function is not available, nor any function to extract individual elements from a vector, but these can be readily calculated by the user.
Vectors can also be used to simply store up to three real numbers together, thereby increasing the calculator's storage capacity, though with more complexity and reduced speed. HP have published program code for the 35s which enables this.
Number bases.
The calculator can be set to display values in binary, octal, or hexadecimal form, as well as the default decimal. When a non-decimal base is selected, calculation results are truncated to integers.
Regardless of which display base is set, non-decimal numbers must be entered with a suffix indicating their base, which involves three or more extra keystrokes.
When hexadecimal is selected, the row of six keys normally used for floating-point functions (trigonometry, logarithms, exponentiation, etc.) are instead allocated to the hex digits A to F (although they are physically labelled to ).
In non-decimal bases, the word length is fixed at 36 bits, and uses two's complement negation. Six bitwise operations are available: , , , , , and .
Statistics and probability.
The 35s's statistics capabilities are fairly standard. It can process a set of one-variable or two-variable statistics. Calculated results include means, weighted mean, standard deviation, and linear regression figures. The summation registers are also accessible for further calculations.
Probability functions (combinations and permutations) are available, as well as random numbers.
Memory and variables.
The 35s provides 30k bytes of user memory, which is shared among data, stored equations, and programs.
Since complex numbers and vectors of up to three elements can be stored as a single value, each data variable occupies 37 bytes, enough for a type indicator and three floating-point numbers.
The 26 alpha-labelled variables and the six statistics registers are permanently allocated; the rest of the memory space can be occupied by up to 801 more variables which can only be accessed indirectly. Indirect access to any variable is achieved by storing its sequence number (0 upwards) in the or variable as a pointer and then accessing the variable via or . The indirect variables are allocated automatically; storing a non-zero value in one results in the allocation of all variables with sequence numbers up to and including the one specified. Conversely, storing a zero value in the highest-allocated indirect variable results in the automatic deallocation of indirect variables downwards until a non-zero value is encountered. Attempting to read a non-allocated variable results in an error. It is therefore common practice to store a dummy non-zero value in a higher-numbered variable than is needed, to ensure that all lower-numbered variables are made available regardless of their values. The permanently allocated variables and the statistics registers may also be accessed indirectly, using negative sequence numbers of -1 to -32.
The calculator provides a set of 41 mathematical and physical constants, which may be scrolled through and selected using the key. A set of 12 binary flags are available; every flags can be set by the user to determine the behaviour of the calculator, five of these may be used for any purpose.
Stored equations occupy a byte for each character and three bytes overhead.
Program steps occupy three bytes. Steps which specify values or equations occupy more memory, as indicated above.
The amount of used and available memory can be readily checked by the user, but not by programs. The user can clear all indirect variables above a specified number, with the function.
Equations.
As well as variables and programs, the user can store any number of equations in the calculator. "Equations" in this context means expressions ( "f(x...)" ), equalities ( "f1(x...) = f2(x...)" ), and assignments ("y = f(x...)"), which are each handled in different ways. Equations typically include named variables whose values are to be supplied by the user at run time, but can also take values from the stack.
Equations are entered in algebraic notation, even when RPN entry mode is active. They are stored in a list which is accessed with the key, allowing the user to scroll through the list, add, edit and delete equations, and select an equation to be processed.
An equation may be processed in a number of ways.
There are also two built-in entries in the equations list, to allow solving all variables in a system of linear equations. Systems of two equations with two variables, and three equations with three variables, are supported.
Solving and (especially) integrating equations take both time and memory. Efficiencies may be made by reducing the display precision and ensuring enough memory is available.
Since the content of an equation is not validated unless and until it gets processed, it may contain any sequence of characters, including text strings. This may be taken advantage of in order to include lines of notes in the equations list (as is shown in the main picture at the top of this page).
Programming.
The HP 35s is keystroke-programmable, meaning that it can remember and later execute sequences of keystrokes to solve particular problems of interest to the user. Program keystrokes are fully merged: functions accessed via shift keys or menus are recorded as one keystroke, not two or more. These keystroke programs, in addition to performing any operation normally available on the keyboard, can also make use of conditional and unconditional branching and looping instructions, allowing programs to perform repetitive operations and make decisions.
All programs are stored in one continuous program space, and may be created and edited by switching to programming mode, using the key. Within the program space, up to twenty-six alphabetic labels may be defined in the form , and each label may be followed by up to 998 other steps, so that any step may be targeted by a ("go to") or ("execute") instruction in the form (or just for the label step itself, A001). Any steps before the first label are numbered with four digits, but these steps cannot be targeted. Subsequent insertion or deletion of steps in program space results in the automatic correction of GTO/XEQ instructions to reflect changes to the targeted step numbers. It is conventional to use each label to mark the start of a separate program, so that any program may be executed by a command in the form . Program execution can be interrupted or resumed by pressing the ("run/stop") key, and the program step pointer can be moved using the and keys. There is no connection between program labels and the variables of the same names.
As in normal operation, programming can be done in either RPN or algebraic (infix) mode. RPN-mode programs are usually smaller and faster.
Here is a sample program that computes the factorial of an integer number from 2 to 69 (ignoring the calculator's built-in factorial/gamma function). There are two versions of the example: one for algebraic mode and one for RPN mode. The RPN version is significantly shorter.
Algebraic version:
RPN version:
Equations may be embedded in programs, as a single program step. The calculator's settings include a numbered flag which specifies whether equations in programs are to be evaluated or displayed at run time. Since an equation can contain any sequence of characters, it may be composed as a message to be displayed. After displaying a message, the program either stops until is pressed, or if a (pause) instruction follows the message then it pauses for one second before continuing.
Programs may be solved and integrated in much the same way as equations. Instead of selecting an equation from a list, the user presses , then the program's label, and either or , which prompts for the name of the target variable. The existing values of the other variables are used, unless the program contains instructions to make the program prompt for a value. In the case of solving, the program is treated as an expression whose return value (the value left on the stack) should be zero. Programs can also contain instructions for solving and integrating other equations/programs.


Server Assistant

Server Assistant is the first program that is run after an install of Mac OS X Server. It can be run again to execute further configuration on a remote or local server. It is also capable of executing remote installation of software onto the server as well.
Server Assistant is a software wizard that guides the administrator through setting up functions of Mac OS X Server.
It is accessible from Finder > Applications > Server > Server Assistant


VSIP

The Visual Studio Industry Partner (VSIP) Program (formerly Visual Studio Integration Program) allows third-party developers and software vendors to develop tools, components and languages for use in the Microsoft Visual Studio .NET IDE. The program offers partnership benefits including co-marketing opportunities, and Visual Studio licensing options as well as extended access to Microsoft technical and premier support.
The VSIP SDK (software development kit) facilitates development of integrated tools and includes development software and documentation that can be used within the Visual Studio .NET IDE directly. Extensions to the IDE, also known as "Add-ins", can be as simple as adding a custom server control to the toolbox, or as complex as adding support for a new CLR-compliant language.
Visual Studio Express is limited and does not support third-party extensions.


Dirname

codice_1 is a standard computer program on Unix and Unix-like operating systems. When codice_1 is given a pathname, it will delete any suffix beginning with the last slash (codice_3) character and return the result. codice_1 is described in the Single UNIX Specification and is primarily used in shell scripts.
History.
The version of codice_1 bundled in GNU coreutils was written by David MacKenzie and Jim Meyering.
The command has also been ported to the IBM i operating system.
Usage.
The Single UNIX Specification for codice_1 is:
 dirname string
Examples.
dirname will retrieve the directory-path name from a pathname ignoring any trailing slashes
$ dirname /home/martin/docs/base.wiki
/home/martin/docs
$ dirname /home/martin/docs/.
/home/martin/docs
$ dirname /home/martin/docs/
/home/martin
$ dirname base.wiki
$ dirname /
Performance.
Since codice_1 accepts only one operand, its usage within the inner loop of shell scripts can be detrimental to performance. Consider
 while read file; do
 dirname "$file"
 done < some-input
The above excerpt would cause a separate process invocation for each line of input. For this reason, shell substitution is typically used instead
 echo "${file%/*}";
or if relative pathnames need to be handled as well
 if [ -n "${file##*/*}" ]; then
 echo "."
 else
 echo "${file%/*}";
 fi
Note that these handle trailing slashes differently than dirname.
Misconceptions.
We might think that paths that end in a trailing slash are a directory. But actually, the trailing slash represents all files within the directory.
 /home/martin/docs/.


Phantasie

Phantasie is the first video game in the "Phantasie" series.
Gameplay.
Based on the Isle of Gelnor, "Phantasie" allows a group of six characters to adventure the countryside and try to defeat the evil Black Knights and their sorcerer leader, Nikademus. Players could choose to be one of six character classes (Thief, Fighter, Ranger, Monk, Priest, and Wizard) and could also choose between the races of Human, Dwarf, Halfling, Elf, or Gnome. By selecting "Random" one could also choose from ogre, troll, pixie, gnoll, orc, lizard man, minotaur, and other races.
The game was notable for taking advantage of a broad mix of styles for the game: a town window which allowed purchasing in various shops, a top-down style dungeon crawl view, a top-down world map, and a separate combat window. Each character class had unique fighting styles and options and all characters could choose their strategy for a particular round in the turn-based combat segments. After a combat, experience was awarded, but the players would have to return to town to purchase their levels if they qualified.
Reception.
With more than 50,000 copies sold in North America, "Phantasie" was very successful for SSI. It was the company's best-selling Commodore game as of late 1987. Game reviewers Hartley and Pattie Lesser in 1987 complimented the Atari ST version of "Phantasie" in their "The Role of Computers" column in "Dragon" #120 (1987), recommending that Atari ST owners should "consider "Phantasie" as a game well-worth their attention." "ANALOG Computing" in 1988 called "Phantasie" and its sequel the best fantasy role-playing games for the Atari 8-bit. In 1991 and 1993 "Computer Gaming World"s Scorpia called "Phantasie" "a surprisingly good little game, with many interesting features".
Legacy.
"Phantasie I", "Phantasie III", and "Questron II" were later re-released together, and reviewed in 1994 in "Dragon" #203 by Sandy Petersen in the "Eye of the Monitor" column. Petersen gave the compilation 2 out of 5 stars.


Better Light

Better Light, Inc. is a company in San Carlos, California, US that manufactures high-end digital scanning backs for view cameras, which are used in many photographic applications including; landscape, commercial advertising, fine art reproduction and architecture.
Better Light scan backs replace the common 4x5 film cassettes used in all 4x5 view cameras of both the studio and field types and also works in copy stands and microscopes that have 4x5 film stages on them as well. The form factor is close to the same one found in the Polaroid 545 Land Film Holder. As a scanning system (opposed to the instant capture systems), conceptually similar to a desktop flatbed scanner redesigned to fit into a Polaroid 545 back.
Better Light scan backs start at the low end using 54 MP to record images of 106 MB of data and then progressively go up through systems of: 144 MP at 274 MB, 216 MP at 618 MB, 384 MP at 488 MB, 416 MP at 794 MB, and finally (in panorama mode) up to approximately 2 GP at 3.8 GB. Unlike most instant capture systems, which only capture one third of the true RGB values for every point in the scene and thus interpolate every pixel up 300% to compensate for this, Better Light systems in their normal mode capture the full RGB values for every point in the scene and use no spatial interpolation. Instant capture systems (besides using interpolation algorithms on every image) also commonly use sharpening, anti-aliasing, anti-moire and compression algorithms on every image as well. Better Light systems, when used in their normal mode, use no post capture processing algorithms at all and always provide files with extremely high color accuracy and information densities. Diamonds provide a great example of the necessity of needing to record critical color accurately without interpolation since interpolation creates spurious color artifacts in an otherwise perfectly clear "white" diamond.
Since Better Light systems are not instant capture and take some time to scan the image, they are mostly suitable only for shooting static scenes unless the resulting geometric distortion of the moving parts of the scene is the desired artistic effect. And while they are not recommended for portraiture some photographers successfully take portraits with them anyway. Many landscape and even oceanscape photographers also successfully use these scanning systems for their work as well.
The company's president, Mike Collette, worked as an instrumentation engineer before starting the company in 1992.


APF Imagination Machine

The APF Imagination Machine is a combination home video game console and home computer system released by APF Electronics Inc. in late 1979. It has two separate components, the APF-M1000 game system, and an add-on docking bay with full sized typewriter keyboard and tape drive. The APF-M1000 was built specifically to compete with the Atari 2600. The full APF Imagination Machine, including the APF-M1000 console and the IM-1 computer component, originally sold for around ().
Overview.
APF Basic.
The bundled APF Basic interpreter allows any users to develop their own programs. Most retailers of the system offered a full and hefty instruction manual to explain how the specialized code works, and a tech sheet that specifies every function of every chip on the console, so as to allow the users to make the most efficient code possible. To encourage more home users to create their own games and trade them, a monthly mailing list lasted well through the video game crash of 1983 and into the next generation of consoles.
Special cassette.
One of the most marketed features of the console is the dual-sided cassette drive that allows the user to write or use a stored program, and also to record or play audio. The feature is generally used for programmers to leave notes about their work, or for instructions to be read aloud before a game is played.
Peripherals.
The console has a number of aftermarket add-ons:
It has a hub of sorts, generally called the "building block", which allows for the connection of some standard computer accessories.
Games.
In addition to the 1 Basic interpreter cartridge bundled with the system, only 15 official game cartridges were ever released by APF Electronics Inc, although several cartridges contain multiple games. Many games were created by an active programming community of owners and distributed through the monthly newsletter, released on cassette tape or printout.
The official game list is as follows:
APF IM-2 console.
APF had planned on releasing a follow up to the original M1000 Imagination Machine game console, but went out of business just before the console could go to market. No official specs have ever been released, although some former employees have mentioned that it was essentially the same M1000 core with typical upgrades.
Development.
The impetus for the Imagination Machine was to beat to market Atari's preannounced but never-launched plans to extend the Atari 2600 to become a home computer. The design was inspired by reverse engineering the TRS-80, Commodore Pet, and Apple I home computers. Working directly with Fairchild Semiconductor, the team got much of its I/O design from Andy Grove. The engineering department wanted to make the design modular for optional expansion, but the marketing department wanted to bundle some features, so the preliminary result was an integrated cassette tape drive. This was removed when, three months later, the first floppy drives appeared on the market which were a superior storage technology.
Reception.
"Games" magazine said in mid-1980, "APF's hardware is impressively solid in both design and performance, and if you're not ready to plunk down $600, you can buy just the game system (MP 1000) for $130 and decide later if you really want the computer component. But it's the whole system that's exciting. If what you want is just a video game, you may as well stick with Atari." "Mechanix Illustrated" in October 1980 called the system "one smart television that's inexpensive, completely programmable, and easy to use". The magazine praised its large RAM and ROM capacities, and called it the first computer that can let the user store new data on the same cassette as the application.


Motorola Xyboard

The Motorola Droid Xyboard, previously released as the Xoom 2 in Europe before being renamed, is an Android-based tablet computer by Motorola Mobility, announced by Motorola on November 3, 2011.
Compared to its predecessor, the Motorola Xoom, Motorola's website said that the Motorola Droid Xyboard would be "10 percent lighter", "33 percent thinner", have an "improved HD 10.1-inch screen", and would be able to "stream PC files to your tablet with MotoCast™".The device is available in 3G and WIFI variants with there being options between an 8.2-inch screen or a 10.1-inch screen model. The website also claims the tablet's 1.2 GHz dual-core processor "boosts speed by 20 percent".
There is an optional active capacitive stylus available, sold separately.
Media Edition.
The Droid Xyboard is also available as a Media Edition. The Motorola website states that the Media Edition will "Stream files from your PC" with "MotoCast™" and has an 8.2-inch "HD widescreen" with "Adaptive virtual surround sound". The Media Edition does not support the active stylus.
Availability.
UK.
Both Xoom 2 tablets were released in November 2011, and are available in the UK at Carphone Warehouse, Best Buy, Dixons, PC World and Currys in the United Kingdom.
North America.
The Droid Xyboard was released in some stores on December 9, and was released in all stores on December 12, 2011.


Casio FX-602P series

The FX-601P and FX-602P were programmable calculators, manufactured by CASIO from 1981. It was the successor model to the Casio FX-502P series and was itself succeeded in 1990 by the Casio FX-603P.
Display.
The FX-601P series featured a single line dot matrix display with 11 characters as main display. An additional 3 digits 7-segment display used to display exponents as well as program steps when entering or debugging programs. There were 11 status indicators.
Programming.
The programming model employed "key stroke" programming by which each key pressed was recorded and later played back. On record, multiple key presses were merged into a single programming step. Only a few operations needed two bytes. Synthetic programming was possible but not very common
The FX-601P could store 128 fully merged steps and data could be stored in 11 memory register. The memory of the FX-602P could be partitioned between from 32 to 512 fully merged steps and data could be stored in 22 to 88 memory register. The default set-up was 22 register and 512 steps. From there one could trade 8 steps for one additional register or 80 steps for 11 register with the 11th register begin a so-called "F" register.
Like its predecessor the FX-602P series supported 10 labels for programs and subroutines called P0 .. P9. Each program or subroutine could have up to 10 local labels called LBL0 .. LBL9 for jumps and branches.
The FX-601P and FX-602P supported indirect addressing both for memory access and jumps and therefore programming model could be considered Turing complete.
Both the FX-601P and FX-602P could load and execute programs from the predecessors.
Programming example.
This program computes the factorial of an integer number from 2 to 69. For 5!, the user enters codice_1 codice_2 to produce the result, 120. The program occupies 9 bytes of memory.
Interface.
The FX-601P and FX-602P used the same FA-1 interface as used by the FX-502P line of calculators or alternatively the newer FA-2 interface which was also used by Casio FX-702P. Both interfaces featured a Kansas City standard Compact Cassette interface.
The FA-2 Interface was used the FX-602P series of programmable calculator and the FX-702P Pocket Computer to store programs and data register to Compact Cassette. When compared with its predecessor the Casio FA-1 the FA-2 featured an additional tape control output and connector for the Casio FP-10 printer.


WASTE text engine

The WASTE (an acronym for WorldScript-aware styled text engine) is an Apple Macintosh text editing software library. WASTE helps Macintosh programmers include advanced text display and editing in their applications.
WASTE is a memory-based editor, which places no arbitrary limit on the amount of text being edited, up to available system memory. It supports the Macintosh WorldScript system, allowing it to handle double-byte character sets and bi-directional text. It includes automatic support for undo operations, drag and drop editing, text justification, embedding images into text, and low-level hooks for rendering and measuring text.
WASTE version 2.0 gained support for paragraph-level formatting, additional character styles, multiple undo and redo operations, Unicode translation, and Mac OS X Carbon support, as well as providing new application programming interfaces (APIs) for printing and string matching.
WASTE is a popular third party library used in many Macintosh applications, formerly under the Classic Mac OS and more recently under Mac OS X, including Netscape Navigator, Internet Explorer, Microsoft Entourage, Microsoft Outlook for Mac, REALbasic, and Tex-Edit Plus.
Since WASTE uses deprecated QuickDraw features, it was deprecated in Mac OS X version 10.4 and unsupported as of version 10.6.


Sony U series

The Sony U series of subnotebook computers refers to two series of Sony products the PCG-U and the VGN-U . The later VGN-U were, at their release, the smallest independent computers running Windows XP and the most powerful high-end subnotebooks at the time. The VGN-U50 and VGN-U70P models are roughly the size of two DVD cases stacked on top of each other.
The first models of the series to come out were the VGN-U50 and the VGN-U70P in Japan. The American model is the VGN-U750P. A VGN-U8G model was introduced for some south Asian countries.
Technical specifications.
Additional specification for VGN-U series
Other:
Docking station:
Advanced technical information for the VGN-U series.
CPU.
The Pentium-M series CPU (1.0 GHz, 1.1 GHz) supports SpeedStep, which allows the processor to slow down when not under load, using less power and prolonging battery life. The 1.1 GHz is a Dothan generation processor, and has a 2 MB cache, whereas the 1.0 GHz is a Banias generation CPU with only 1 MB of cache. The 900 MHz Celeron-M does not support SpeedStep, and has only 512 KB cache. Despite the Celeron-M's performance shortcomings, benchmarks show the arithmetic performance difference is marginal. Much of the performance increase seems to result from having a total of 512 MB of memory. Battery life of the Pentium-M series is said to be anywhere from 30 to 45 minutes over the Celeron-M model as a result of having SpeedStep.
Display.
The internal display has a resolution of 800x600 pixels. The integrated i855gm graphics card can display a maximum of 16 million colors. Connecting an external monitor to the VGA port of the docking station enables a maximum resolution of 1600x1200x16m. The graphics supports display cloning or extended desktop when using an extended monitor, and also supports OpenGL and Direct3D hardware acceleration, with a performance approximating that of a Radeon 7000 or a GeForce 1. With updated drivers from Intel, the ability to rotate the screen in 90, 180 and 270 degree modes is enabled.
The brightness of the internal display is adjustable. The brightness control has nine levels, and also the ability to turn the backlight off in direct sunlight.
The display is very small, roughly 5 inches (127 mm) diagonal; it may cause some eyestrain if it used for prolonged periods. The high DPI resolution offers excellent viewing of images and video.
Keyboard.
Sony VGP-KBC1 Foldable Keyboard,
The compact USB keyboard resembles a laptop keyboard. It folds in the middle, and has a TrackStik mouse pointer in the center. When folded, the unit is approximately the same width and height of the U-series unit, and about half the thickness. Original U50 and U70p units had a faulty Synaptics driver which sometimes caused USB HID input device conflicts. Recent driver updates have resolved this issue.
TrackStik and mouse buttons.
The pointing-head is on the right side of the unit below the directional pad. The mouse buttons are on the left side of the unit, no matter what orientation it is used in. When rotated into portrait mode, the options key, brightness, and onscreen keyboard button are remapped to the mouse buttons, and the previous mouse buttons become the new modifier buttons.
The TrackStick has a rubber tip that can be worn out after repeated use. You can get a replacement tip from Sony parts.
CompactFlash slot.
This slot will accommodate a Type-II CompactFlash device, provided there are Windows XP drivers for such a device. It will accept all valid CompactFlash memory cards. Some memory cards pulled from sealed MP3 devices such as iPods have been crippled as so not to be fully compliant as a regular memory card, and may not work.
Memory Stick slot.
The Sony Memory Stick slot is underneath the CompactFlash slot. It will accept only Memory Stick memory storage cards; Wi-Fi and Bluetooth cards will not work as there are no Windows XP drivers for any such Memory Stick IO devices at this time.
Headset connectors.
There is one headset connector on the left hand side of the unit, above the button-hold switch. It also has an extended port for a headphone remote control unit, which allows one to control audio playback and read current track information. There are a couple extensions available to allow Windows Media Player and Winamp to display output to the controller unit.
Rechargeable battery.
There are two OEM batteries available, and now some aftermarket enhanced models. The stock one that comes with all units lasts approximately two to three hours, depending on usage. An extended battery is available as an option, is about twice the thickness of the stock battery, and lasts approximately twice as long as the stock battery.
Power supply.
The iGo Juice and other third party adapter manufacturers make power supplies that are compatible with the U series. The power tip is compatible with many other Sony models, including the Z505, and possibly some Fujitsu models. Please check voltage, current and power ratings to ensure maximum compatibility.
RAM & upgrading.
On all models, the memory is on a proprietary daughtercard manufactured by Sony. This card has a proprietary interface, and is incompatible with all currently known memory cards. The memory is DDR 266 MHz. On models with 512 MB, the memory is maxed out. On models with 256 MB, the memory card can be removed and replaced with a 512 MB card, currently only available in Japan, but occasionally rarely found in the United States, and usually at extremely high prices.
Since the U series uses a proprietary memory module and not a standard SODIMM, if a vendor claims to have U-series RAM for sale and it is a SODIMM, it will not fit in the U series. There are various vendors claiming to sell U-series RAM but the vast majority are selling incompatible DDR SODIMM. There has been no report of modules larger than 512MB as of August 2014.
i.Link Firewire port.
i.Link is Sony's name for IEEE 1394; the port is compatible with 4 pin FireWire cables, and is unpowered. 6 pin firewire cables will need an adapter. The i.Link port on the docking station additionally has a power jack next to the 4 pin jack, used only for Sony compatible CD and DVD drives. Only drives compatible with this extended power jack are capable of booting CDs and DVDs on the U series. Other drives may work once booted into the OS, but will not boot setup CDs or DVDs. There are at least four Sony drives that will work: PCGA-CRWD2, PCGA-DVRW1, PCVA-DRW3, and PCGA-DVD1/A.
Models and prices.
The VGN-U70p was produced in 2004 in Japan. It was not available outside Japan, but it was available via import retailers. Only Sony Japan sold the VGN-U70p version directly, while both Sony and other Japanese vendors sold the lower model VGN-U50. A memory upgrade for the U50 is rumored to exist in Japan at an extremely high price.
As of approximately January 2005, Sony Japan had discontinued the U70p, and introduced a new model, VGN-U71p. The upgraded features include a 1.1 GHz CPU with 2 MB of cache, and a 30 GB hard drive.
In December 2004, Sony USA introduced an American model, the VGN-U750. It is identical to the U70, but has an upgraded CPU of 1.1 GHz with 2 MB of cache. It forgoes the Japanese Sony DoVaio media application for an English version of Sony VAIO Media as its media player application. In mid-February 2005, Sony USA's website stopped selling the U750.
In Hong Kong, Singapore, and a few other south Asian countries, Sony had introduced a regional localized model, the VGN-U8G and VGN-U8C. The U8G is identical to the U50, except it came with an external DVD+/-RW i. Link drive.
Availability.
All models of the Sony Vaio U series have been discontinued in lieu of the new UX series.
For a limited time, models U50/U8G/U8C/U70p/U71p/u750p were available from the following vendors (listed alphabetically): As all U models preceding the UX have been discontinued as of 2006, availability of any of the aforementioned U series models on the following websites is either nil, scarce, or sporadic.
Due to their unique design and still-considerable computational power the U series remains in high demand, evidenced by the numerous internet fan communities and the consistent high prices they fetch on online auction sites.


Samsung Ativ Tab 7

The Samsung Ativ Tab 7, "XE700T1C" or previously known as "Samsung Ativ Smart PC Pro", is a tablet manufactured by Samsung. The Ativ Tab 7 was announced on August 29, 2012 at IFA 2012 in Berlin, incorporates a dual-core 1.8 GHz Intel Core i5 - 3337U processor, and runs the Windows 8 operating system.
The incorporation of Windows 8 has received mostly favourable reviews. Also the Ativ Tab 7 itself received positive reviews for its lightweight design, inclusion of S-Pen, and its overall performance for a device positioned as a high-end device.
Hardware.
The design of the Ativ Tab 7 is relatively similar to its smaller Android-based counterparts (such as the Galaxy Tab 2 10.1 and the Galaxy Note 10.1)built using a mixture of plastic and glass. A micro HDMI port, MicroSD slot, and a full-size USB port are incorporated into the design, as well as a volume rocker, power button, and headphone jack located on the top. A physical Windows button is located directly below the screen. A charging port and dock connector are located on the bottom. The Ativ Tab 7 uses a LED Full HD display at a resolution of 1920x1080. The tablet is available with either 128 or 256 GB of internal storage which is expandable via an external micro-sd card.
Reception.
At IFA 2012, TechRadar praised the Ativ Tab 7's Windows 8 operating system, lightweight design, and the ability to expand its functionality and storage with its S-Pen and attachable keyboard. It was also said that there is a plenty amount of USB ports which was even doubled with the attachment of the removable keyboard. Overall they deemed the device as one of the best Windows 8 transformer tablets around.
CNET said that the Ativ Tab 7 performs well, most of the time as docked into the removable keyboard. The tablet's battery life, numerous USB ports, and the pre-installed Samsung software were regarded as positive aspectsdespite considering the design itself to be merely cheap and unusual. The Intel chipset used in the Ativ Tab 7 was also judged as a great for the device noting that its performance was fast and very responsive most of the time in comparison to the chipsets used in competing Windows 8 devices. Over-all they viewed the Ativ tab 7 as more of an overpriced and confused Windows 8 ultrabook that is detachable and is better off with a keyboard as it is best left like that.


Nvidia Tesla Personal Supercomputer

The Tesla Personal Supercomputer is a desktop computer (personal supercomputer) that is backed by Nvidia and built by various hardware vendors. It is meant to be a demonstration of the capabilities of Nvidia's Tesla GPGPU brand; it utilizes NVIDIA's CUDA parallel computing architecture and is powered by up to 2688 parallel processing cores per GPGPU, which allow it to achieve speeds up to 250 times faster than standard PCs, according to Nvidia.


DashCon

DashCon was a fan convention catering primarily to users of the blogging service Tumblr, with a particular emphasis on fandoms. Held over the weekend of July 11, 2014, in Schaumburg, Illinois, the inaugural convention quickly became infamous for allegations of mismanagement and corruption among organizers, an alleged abrupt demand by the hotel for an upfront payment of cash for use of its facilities, and celebrity guests being forced to drop out of the convention after they were informed by the hotel that they would be responsible for paying for their rooms. A small ball pit placed in one of the halls became a meme after organizers offered attendees an "extra hour" in the pit (along with raffle and concert tickets) as reimbursement for a canceled panel.
Organizers for DashCon initially stated that they were going to hold a second DashCon in 2015 despite the issues faced by the inaugural edition, but officially announced via a Tumblr post in September 2014 that DashCon LLP was going to be dissolved and all its assets liquidated, meaning that they were not going to hold a second convention. The post also denied claims that a similarly themed convention, Emoti-Con, was a re-branded DashCon.
Concept.
DashCon was originally announced in mid-2013 under the name Tumbl-Con USA, as a convention catered to users of the blogging platform Tumblr, and was touted as the "largest gathering of Tumblr users to date". The convention was to focus on works that had developed significant followings among Tumblr users, such as "Doctor Who", "Sherlock", "Supernatural" and the podcast "Welcome to Night Vale". The convention raised money through ticket pre-orders, along with a crowdfunding campaign on Indiegogo. Prior to the start of the convention, the name of the event was changed to DashCon (alluding to the site's dashboard feed) to indicate that it was not officially associated with Tumblr.
Convention.
The convention was organized by DashCon LLP, a Hudson, Ohio-based limited liability partnership owned by Megan Eli and Roxanne Schwieterman. DashCon was held from July 11 to 13, 2014, at the Renaissance Schaumburg Convention Center Hotel. Among the guests originally scheduled to attend were actor Doug Jones, webcomic artist Noelle Stevenson, and the cast of "Welcome to Night Vale".
On the evening of July 11 – the first night of DashCon – early reports began to surface from attendees that events occurring at the convention were poorly planned and attended, a vendor had left due to poor sales, and minors had been admitted into 18+ rated panels. The convention itself also began to experience unexpected financial difficulties: a DashCon staff member claimed that the staff of the Renaissance purportedly informed them that they would need to pay $20,000 upfront for the use of the facilities, or shut the convention down. DashCon organizers claimed to have verbally negotiated to pay the venue gradually throughout the convention using ticket sales, rather than issuing an upfront payment despite their contract suggesting otherwise.
At 9:00 p.m. CT, as a result of this unexpected development, the DashCon organizers began to publicly solicit donations among a crowd of around 350 attendees (itself much lower than the original estimate of 3,000 to 7,000 attendees), and online via PayPal, to cover costs, with a goal of collecting at least $17,000 by 10:00 p.m. to prevent the convention from being shut down. Organizers speculated that the abrupt change in plans was because the hotel's management "[did not] like the people at the con". Attendees were seen performing a three-fingered salute from "The Hunger Games", chanting lines from "High School Musical", and singing Queen's "We Are the Champions" and "Do You Hear the People Sing?" from "Les Misérables". While organizers managed to raise the necessary funds, the incident raised suspicion among attendees over the possibility of the crowdfunding drive being a scam (which included disputes over the authenticity of an image of the bill, printed on hotel stationery, which was released by a staff member), or being further proof of the alleged mismanagement and corruption.
Several guests – including Noelle Stevenson (who had to moderate their own panel because the scheduled moderator was absent), the Baker Street Babes (who produced an all-female Sherlock Holmes podcast), and the "Welcome to Night Vale" cast – were also informed by the hotel that they would be responsible for paying for their own rooms, despite previously being told that the rooms would be paid for by the convention itself. Stevenson would ultimately join the "WTNV" cast for the night in accommodations obtained via Airbnb. The appearance by the "Welcome to Night Vale" cast was ultimately canceled; organizers did not issue refunds but instead reimbursed those who had purchased tickets for the panel with tickets to a raffle of various autographed collectibles, admission to a concert with the Chicago-based "Doctor Who"-inspired rock band Time Crash, and an "extra hour with the ball pit".
Reception and aftermath.
The ball pit – roughly the size of a kiddie pool, in an otherwise empty concession hall – and the notion of an "extra hour" in it, quickly became a meme among attendees and other Tumblr users, inspiring parodies. Users envisioned other large quantities of items that could have been purchased with the $17,000, and a video game developer created "Dashcon Simulator 2014", a comedic simulation of the convention's ball pit. Convention guest Mark Oshiro explained that the ball pit was "not a point of interest, it wasn't something a single soul talked about, and it was just a quirky thing that existed", and that "in order to support the idea that DashCon was a full, 100 percent disaster, every single detail was used to paint the con and the people at it as horrific failures of humanity".
In the aftermath of the convention, a staff member of the hotel stated that the facility did enjoy their presence, while DashCon's staff promised to provide a more thorough explanation of what had occurred. The Baker Street Babes reported that the hotel payment issue was, according to organizers, a mistake. Stevenson, whose hotel payment had not yet been resolved, defended criticism of DashCon by other users, arguing that they were unfamiliar with what typically occurs at a convention in the first place.
Near the end and after the convention had finished, suspicion rose that the event was a cash grab by the convention organizers. It was noted that when organizers were asked to pay the remaining $20,000 to continue the convention, it was claimed that only $3,000 had been accrued by then. During the donation drive, third-party sources and testimonies claim that around $750 was collected onsite, with the remainder made in electronic transactions. A leaked payment statement, however, listed $11,750 had been paid in cash, causing observers to accuse convention organizers of pocketing a substantial amount of the donations, though organizers denied this claim.
Emoti-Con.
In September 2014, "The Daily Dot" published an article where they reported on concerns that DashCon had renamed/rebranded itself Emoti-Con. The writer noted that the two conventions were nearly identical in their themes, that Emoti-Con was to be held in the same venue that the second DashCon was to be hosted at, the Emoti-Con website contained much of the same text as the DashCon website, and that it was being organized by one of the co-creators of DashCon. DashCon later denied that the two cons were the same via a post on their official Tumblr account, where they stated that while Emoti-Con was being organized by two of the three owners of DashCon, the two events are otherwise unrelated to one another. They also stated that Emoti-Con would be "functioning under a very different infrastructure than DashCon did, with a more experienced and well-rounded staff". Emoti-Con was later canceled, with their official Tumblr account citing "personal, financial, and safety" issues.


BASIC-E


Rotating line camera

A rotating line camera is a digital camera that uses a linear CCD array to assemble a digital image as the camera rotates. The CCD array may consist of three sensor lines, one for each RGB color channel. Advanced rotating line cameras may have multiple linear CCD arrays on the focal plate and may capture multiple panoramic images during their rotation.
Line-scan technology is capable of capturing data extremely fast, and at very high image resolutions. Usually under these conditions, resulting collected image data can quickly exceed 100 MB in a fraction of a second. Line-scan-camera–based integrated systems, therefore are usually designed to streamline the camera's output in order to meet the system's objective, using computer technology which is also affordable.
Line-scan cameras intended for the parcel handling industry can integrate adaptive focusing mechanisms to scan six sides of any rectangular parcel in focus, regardless of angle, and size. The resulting 2-D captured images could contain, but are not limited to 1D and 2D barcodes, address information, and any pattern that can be processed via image processing methods. Since the images are 2-D, they are also human-readable and can be viewable on a computer screen. Advanced integrated systems include video coding, optical character recognition (OCR) and finish-line cameras for high speed sports.
Panoscan.
The Panoscan is a high resolution digital panoramic rotating line camera, manufactured by Panoscan Inc. The first Panoscan camera, called MK-1, was manufactured in 1999. The MK-2 and MK-3 models, with higher resolution and speed, followed. Panoscan uses a tri-linear CCD array and assembles an image by capturing a single line of pixels while rotating through a 400 degree arc. A full resolution, spherical image can be produced in under a minute. The camera produces digital images of 9,000 by 65,000 pixels that can be printed at 30 feet (10 metres) in length. The camera incorporates a pan mechanism and does not require an external unit.


Stattoo

Stattoo is a Dashboard-like information display tool for Mac OS X by Panic. It can display the time, date, current music, upcoming iCal events, email inbox status, temperature, software updates, hard drive capacity, and battery charge.


Fast loader

A fast loader is a software program for a home computer, such as the Commodore 64 or ZX Spectrum, that accelerates the speed of file loading from floppy disk or compact cassette.
Floppy disks.
Background.
Fast loaders came about because of a discrepancy between the actual speed at which floppy drives could transfer data and the speed that was provided by the operating system's default routines. This discrepancy was most pronounced on the Commodore VIC-20 and 64. While the earlier Commodore PET series had used an industry-standard IEEE-488 parallel bus, this was replaced with a custom Commodore serial bus on the VIC-20. The serial bus was intended to be nearly as fast as its predecessor, due to the use of the 6522 VIA as a hardware shift register on both the drive and computer. However, hardware bugs were discovered in the 6522 that prevented this function from working consistently. As a result, the KERNAL ROM routines were hastily rewritten to transfer a single bit at a time, using a slow software handshaking protocol.
Although the C64 replaced the 6522 VIA with two 6526 CIA chips, which did not suffer from this bug, the companion 1541 disk drive still had a 6522 VIA. Commodore chose not to redesign the 1541 hardware, also in order to retain backward compatibility with VIC-20 peripherals; this however came at the expense of speed. Because of the transfer protocol, the Commodore 1540 and 1541 disk drives soon gained a reputation for extreme slowness. Only at the introduction of the Commodore 128 computer and the Commodore 1571 disk drive was the original plan put into action and a hardware shift register was used, reducing the need for special fast loaders.
Development.
Soon after the C64's release, some astute programmers realized that Commodore's bit-banging serial KERNAL routines were unnecessarily sluggish. Since the CPU in the C64 ran at approximately the same speed as that in the 1541 disk drive, it was sufficient to synchronize only at the beginning of each byte, rather than at each individual bit. Moreover, this transfer method allowed two bits to be sent simultaneously, one over the standard codice_1 line and one over the codice_2 line (which was normally used to perform the handshaking). On the C64, this required very careful timing to avoid interference from interrupts and from the VIC-II graphics chip, which could "steal" CPU cycles. Some fast loaders disabled interrupts and blanked the screen for this reason. A fast loader would generally "wedge" itself into the codice_3 vector at codice_4, thus intercepting any calls to the KERNAL codice_3 routine. Next, the fast loader would transfer the necessary code into the drive RAM and order its execution, then receive the file sent by the altered transfer code. Depending on the exact nature of the routines used, the loading speed could be improved by as much as a factor of five.
This technique was used for a few of the many fast-load systems made (such as JiffyDOS). Others were simply more efficient in I/O and file handling, offering marginal to good improvement. Other products added parallel hardware.
Commercial fast loaders.
Various software companies released fast loaders for the C64, usually in cartridge form. In the United States, probably the most popular such cartridge was the Epyx FastLoad. Most fast loader cartridges also incorporated other features to increase ease of use. An on-board implementation of Commodore's DOS Wedge was included in most fast loader cartridges. Machine language monitors, disk editors, and various convenience commands for Commodore BASIC were also common additions. Some fast loader cartridges were very sophisticated, incorporating a reset button, "freeze" capabilities, and a simple onboard GUI. The Final Cartridge III was perhaps the most successful of this genre. A few commercial fast loaders, most notably CMD's JiffyDOS, were not cartridge-driven but instead replaced the KERNAL ROM in the C64 and the DOS ROM in the 1541. While these were more difficult to install, they offered greatly increased compatibility, being almost invisible to software running on the machine.
The cartridge, Action Replay MK6 RAM loader loads a 202 block program in around 9 seconds. Its Warp loader is 25 times faster, but programs can only be loaded with a loader saved to disk when the cartridge is not present.
Whereas the ARMK6 fastloader was compatible with most software, The Final Cartridge III was known to crash often, so programs had to be loaded in normal C64 mode, deactivating the cartridge, making it more or less useless.
Many commercial programs for the C64, especially games, contained their own fast-loading routines on the distribution media. The user would load a small "stub" program from the disk with the standard slow routines, which would then install faster transfer routines in both the computer and the drive before proceeding to load the rest of the program at high speed. This way, the user benefited from the fast loader without having to buy or know about a dedicated fast-loader product.
Type-in fast loaders.
Several popular Commodore magazines published type-in fast loading software. In April 1985, "Compute!" published "TurboDisk", a fast loader that included C64 and VIC-20 versions. This program proved popular and was republished in the July 1985 issue of "Compute!'s Gazette".
It was printed yet again in August 1986, without the VIC-20 version, but with several accompanying utilities to relocate the program in memory and to create auto-booting software that took advantage of "TurboDisk"'s speed. A Commodore 128 version was also included for those C128 users who still had 1541 disk drives.
"COMPUTE!'s Gazette" also published several other utilities that speed up C64-to-1541 communications, including "Turbo Copy" (a 4-minute full-disk copier), "TurboSave" (a utility that accelerated the speed of disk saves) and "Quick!" (another fast loader).
"RUN" Magazine published "Sizzle!" in December 1987, an integrated package that included a relocatable fast loader with autoboot generation capability.
"BYTE" published Loader, a machine-language fast-loading software for Apple DOS 3.3, in November 1983. "Compute!" published TurboDisk for DOS 3.3 in October 1986.
The type-in fast loader fashion continued in the age of the Internet. "Krill's Loader" (2009) and "Spindle" (2013) are two examples of C64-to-1541 "IRQ loaders", fast loaders that allow programs (mainly games) to keep their own IRQs during loading. With modern loaders the slow rate of GCR decoding proved to be the bottleneck, and modern loaders all carry their own optimized routines for such.
Cassette tapes.
The built-in routines for storing and reading data to and from Compact Cassette tapes was made for safe storing rather than speed. Better tape-quality in the 1980s made it possible to store data more effectively, reducing loading time and tape length.
Such programs existed for several computers, such as the Ohio Scientific Challenger. The PET Rabbit was one such program for the PET, while TurboTape was one for the Commodore Datassette. Turbo 2000 was a similar system for the Atari.
Invade-a-Load was a fast loader for cassette-based games which not only accelerated the loading of blocks from the tape, but also contained a mini-game (in this case, a clone of "Space Invaders") that could be played while waiting for the main game to finish loading.


Lists of microcomputers

For an overview of microcomputers of different kinds, see the following lists of microcomputers:


Polipo

Polipo is a lightweight caching and forwarding web proxy server. It has a wide variety of uses, from aiding security by filtering traffic; to caching web, DNS and other computer network lookups for a group of people sharing network resources; to speeding up a web server by caching repeated requests. It can be configured to use on-disk cache and serve cached content when offline and perform various forms of content filtering.
To minimize latency, Polipo both pipelines multiple resource requests and multiplexes multiple transactions onto the same TCP/IP connection. Polipo is HTTP 1.1-compliant, supports IPv4, IPv6, traffic filtering and privacy-enhancement.
Polipo is free software released under the MIT License.
Polipo ceased to be maintained on 6 November 2016 due to the increasingly widespread use of encryption (i.e. HTTPS) making caching proxies obsolete.
Design.
Polipo is designed to be used as a personal web cache or a web cache shared among a few users to boost internet access. Designed to be fast, lightweight and small, it is useful when the system resources for a larger proxy are unavailable. Because of this, it has been put to uses such as a tether on the OpenWrt.
GUI wrappers.
Natively, polipo comes as a highly specialized command-line interface (CLI) software application, which requires commands to be typed on the keyboard and parameters stored in configuration text files. Alternatively, polipo allows users to run the program automated and non-interactively, such as in a shell script. By starting a GUI wrapper application users can intuitively interact with polipo, start and stop it and change its working parameters, through graphical icons and visual indicators.
Some independent GUI wrapper projects are:
Features.
The fast, lightweight and small memory footprint proxy server polipo uses a variety of techniques:
Limitations.
Polipo is limited to 2G or 4G file sizes on 32 bit systems which will cause errors when serving large requests.


SGI O2

The O2 is an entry-level Unix workstation introduced in 1996 by Silicon Graphics, Inc. (SGI) to replace their earlier Indy series. Like the Indy, the O2 used a single MIPS microprocessor and was intended to be used mainly for multimedia. Its larger counterpart is the SGI Octane. The O2 was SGI's last attempt at a low-end workstation.
Hardware.
System architecture.
Originally known as the "Moosehead" project, the O2 architecture featured a proprietary high-bandwidth Unified Memory Architecture (UMA) to connect system components. A PCI bus is bridged onto the UMA with one slot available. It had a designer case and an internal modular construction. Two SCSI drives could be mounted on special caddies (1 in the later R10000/R12000 models due to heat constraints) and an optional video capture / sound cassette mounted on the far left side.
CPU.
The O2 comes in two distinct CPU flavours; the low-end MIPS 180 to 350 MHz R5000- or RM7000-based units and the higher-end 150 to 400 MHz R10000- or R12000-based units. The 200 MHz R5000 CPUs with 1 MB L2-cache are generally noticeably faster than the 180 MHz R5000s with 512 KB cache. There is a hobbyist project that has successfully retrofitted a 600 MHz RM7xxx MIPS processor into the O2.
Memory.
There are eight DIMM slots on the motherboard and memory, and all O2s are expandable to 1 GB using proprietary 239-pin SDRAM DIMMs. The Memory & Rendering Engine (MRE) ASIC contains the memory controller. Memory is accessed via a 133 MHz 144-bit bus, of which 128 bits are for data and the remaining for ECC. This bus is interfaced by a set of buffers to the 66 MHz 256-bit memory system.
I/O.
I/O functionality is provided by the IO Engine ASIC. The ASIC provides a 64-bit PCI bus, an ISA bus, two PS/2 ports for keyboard and mouse, and a 10/100 Base-T Ethernet port. The PCI bus has one 64-bit slot, but the ISA bus is present solely for attaching a Super I/O chip to provide serial and parallel ports.
Disks.
The O2 carries an UltraWide SCSI drive subsystem (Adaptec 7880). Older O2's generally have 4x speed Toshiba CD-ROMs, but any Toshiba SCSI CD-ROM can be used (as well as from other manufacturers, the bezel replacement however is designed to fit Toshiba design and also IRIX cannot utilize CD-DA mode other than Toshiba). Later units have Toshiba DVD-ROMs. The R5000/RM7000 units have two available drive sleds for SCA UltraWide SCSI hard-disks. Because the R10000/R12000 CPU module has a much higher cooling-fan assembly, the R10000/R12000 units have room for only one drive-sled.
Graphics.
The O2 used the CRM chipset specifically developed by SGI for the O2. It was developed to be a low-cost implementation of the OpenGL 1.1 architecture with ARB image extensions in both software and hardware. The chipset consists of the microprocessor, and the ICE, MRE and Display ASICs. All display list and vertex processing, as well as the control of the MRE ASIC is performed by the microprocessor. The ICE ASIC performs the packaging and unpacking of pixels as well as operations on pixel data. The MRE ASIC performs rasterization and texture mapping. Due to the unified memory architecture, the texture and framebuffer memory comes from main memory, resulting in a system that has a variable amount of each memory. The Display Engine generates analog video signals from framebuffer data fetched from the memory for display.
Operating systems.
Several operating systems support the O2:
Performance.
The SGI O2 has an Imaging and Compression Engine (ICE) application-specific integrated circuit (ASIC) for processing streaming media and still images. ICE operates at 66 MHz and contains a R3000-derived microprocessor serving as the scalar unit to which a 128-bit SIMD unit is attached using the MIPS coprocessor interface. ICE operates on eight 16-bit or sixteen 8-bit integers, but still provides a significant amount of computational power which enables the O2 to do video decoding and audio tasks that would require a much faster CPU if done without SIMD instructions. ICE only works with the IRIX operating system, as this is the only system that has drivers capable of taking advantage of this device.
The Unified Memory Architecture means that the O2 uses main memory for graphics textures, making texturing polygons and other graphics elements trivial. Instead of transferring textures over a bus to the graphics subsystem, the O2 passes a pointer to the texture in main memory which is then accessed by the graphics hardware. This makes using large textures easy, and even makes using streaming video as a texture possible.
Since the CPU performs many of geometry calculations, using a faster CPU will increase the speed of a geometry-limited application. The O2's graphics is known to have slower rasterization speed than the Indigo2's Maximum IMPACT graphics boards, though the Maximum IMPACT graphics is limited to 4 MB of texture memory, which can result in thrashing, whereas the O2 is limited only by available memory.
While CPU frequencies of 180 to 400 MHz seem low today, when the O2 was released in 1996, these speeds were on par with or above the current offerings for the x86 family of computers (cf. Intel's Pentium and AMD's K5).
Uses.
O2s were often used in the following fields:


Yaboot

Yaboot (yet another boot loader) is a bootloader for PowerPC-based hardware running Linux.
History.
In 2009, maintenance by Paul Nasrat was handed over to Tony Breeds.
Hardware support.
Support includes the New World ROM Macintosh and IBM RS/6000 systems. It does not support the "OldWorld" PowerMacs.
Booting procedure.
It is built to run within the Open Firmware layer common to most such systems instead of working as a Mac OS 9 program like its predecessor BootX.
Yaboot is similar to LILO and GNU GRUB. Yaboot uses the following steps to boot:


Shar

In the Unix operating system, shar (an abbreviation of "shell archive") is an archive format created with the Unix codice_1 utility. A shar file is a type of self-extracting archive, because it is a valid shell script, and executing it will recreate the files. To extract the files, only the standard Unix Bourne shell "sh" is usually required.
Note that the shar command is not specified by the Single Unix Specification, so it is not formally a component of Unix, but a legacy utility.
Details.
While the shar format has the advantage of being plain text, it poses a risk due to being executable; for this reason the older and more general tar file format is usually preferred even for transferring text files. GNU provides its own version of shar in the GNU Sharutils collection.
"unshar" programs have been written for other operating systems but are not always reliable; shar files are shell scripts and can theoretically do anything that a shell script can do (including using incompatible features of enhanced or workalike shells), limiting their utility outside the Unix world.
The drawback of self-extracting shell scripts (any kind, not just shar) is that they may rely on a particular implementation of programs; shell archives created with older versions of "makeself", for example, the original "Unreal Tournament" for Linux installer, fails to run on bash 3.x due to a change in how missing arguments to codice_2 built-in command are handled.
History and similar formats.
James Gosling is credited with writing the first version of the "shar" utility, and also wrote an early example of the concept in the form of this simple shell script:
AR=$1
shift
for i do
 echo a - $i
 echo "echo x - $i" »$AR
 echo "cat >$i «'!Funky!Stuff!'" »$AR
 cat $i »$AR
 echo "!Funky!Stuff!" »$AR
done
A version of the same concept, but for the VMS operating system, was written in 1987 by Michael Bednarek from The Melbourne Institute of Applied Economic and Social Research as a DCL script, VMS_SHAR.COM. This was later maintained and extended by James A. Gray from Xerox, and Andy Harper from King's College London.
The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities.


Bubble Dizzy

Bubble Dizzy is an arcade style action video game developed by the Oliver Twins and published in November 1990 by Codemasters for the Amstrad, Spectrum, MS-DOS, Atari ST, Commodore 64 and Amiga.
Gameplay.
The game involves Dizzy being forced to walk the plank of a pirate ship and from the sea bed use bubbles to float back to the surface and dry land. Like "Dizzy Down the Rapids", this game derived from a mini-game found in "The Fantastic Adventures of Dizzy".


List of home computers

The home computers between 1977 and about 1995 were different from today's uniform and predictable machines. During this time it made economic sense for manufacturers to make microcomputers aimed at the home user. By simplifying the machines, and making use of household items such as television sets and cassette recorders instead of dedicated computer peripherals, the home computer allowed the consumer to own a computer at a fraction of the price of computers oriented to small business. Today, the price of microcomputers has dropped to the point where there's no advantage to building a separate, incompatible series just for home users.
While many office-type personal computers were used in homes, in this list a "home computer" is a factory-assembled mass-marketed consumer product, usually at significantly lower cost than contemporary business computers. It would have an alphabetic keyboard and a multi-line alphanumeric display, the ability to run both games software as well as application software and user-written programs, and some removable mass storage device (such as cassette tape or floppy disk).
This list excludes smartphones, personal digital assistants, pocket computers, laptop computers, programmable calculators and pure video game consoles. Single-board development or evaluation boards, intended to demonstrate a microprocessor, are excluded since these were not marketed to general consumers.
Pioneering kit and assembled hobby microcomputers which generally required electronics skills to build or operate are listed separately, as are computers intended primarily for use in schools. A hobby-type computer often would have required significant expansion of memory and peripherals to make it useful for the usual role of a factory-made home computer. School computers usually had facilities to share expensive peripherals such as disk drives and printers, and often had provision for central administration.
Attributes.
Attributes are as typically advertised by the original manufacturer. Popular machines inspired third-party sources for adapters, add-on processors, mass storage, and other peripherals.
"Processor" indicates the microprocessor chip that ran the system. A few home computers had multiple processors, generally used for input/output devices. Processor speeds were not a competitive point among home computer manufacturers, and typically the processor ran either at its maximum rated speed ( between 1 and 4 MHz for most processor types here), or at some fraction of the television color subcarrier signal, for economy of design. Since a crystal oscillator was necessary for stable color, it was often also used as the microprocessor clock source. Many processors were second-sourced, with different manufacturers making the same device under different part numbers. Variations of a basic part number might have been used to indicate minor variations in speed or transistor type, or might indicate fairly significant alterations to the prototype's capabilities. In the Soviet Bloc countries, manufacturers made functional duplicates of Western microprocessors under different part number series.
"TV" indicates the factory configuration produces composite video compatible with a home TV receiver. Some computers came with a built-in RF modulator to allow connection to the TV receiver antenna terminals; others output composite video for use with a free-standing monitor or external RF modulator. Still others had built-in or proprietary monitors. Often a composite video monitor (monochrome or color) would be substituted for the family TV. Some standard types of video controller ICs were popular, but see the very detailed List of home computers by video hardware for a discussion of video capabilities of different models. Memory and TV bandwidth restrictions meant that typical home computers had only a few color choices and perhaps 20 lines of 40 characters of text as an upper limit to their video capabilities. Where the same model was sold in countries using PAL or NTSC television standards, sometimes there would be minor variations in the speed of the processor, because NTSC and PAL use different frequencies for the color information and the crystal for the video system was often also used for the processor clock.
Base mass storage was whatever came in the basic configuration. Some machines had built-in cassette drives or optional external drives, others relied on the consumer to provide a cassette recorder. Cassette recorders had the primary virtue of being widely available as a consumer product at the time. Typically a home computer would generate audio tones to encode data, that could be stored on audio tape through a direct connection to the recorder. Re-loading the data required re-winding the tape. The home computer would contain some circuit such as a phase-locked loop to convert audio tones back into digital data. Since consumer cassette recorders were not made for remote control, the user would have to manually operate the recorder in response to prompts from the computer. Random access to data on a cassette was impossible, since the entire tape would have to be searched to retrieve any particular item. A few manufacturers integrated a cassette tape drive or cassette-like tape mechanism into the console, but these variants were made obsolete by the reduction in cost of floppy diskette drives.
Floppy disk drives were initially very costly compared to the system purchase price. Plug-in ROM cartridges containing game or application software were popular in earlier home computers since they were easier to use, faster, and more reliable than cassette tapes. Once diskette drives became available at low cost, cartridges declined in popularity since they were more expensive to manufacture than reproducing a diskette, and had comparatively small capacity compared to diskettes. A few cartridges contained battery-backed memory that allowed users to save data (for example, game high scores) between uses of the cartridge.
Typically there were several models or variants within a product line, especially to account for different international video standards and power supplies; see the linked articles for variants and consequences of variations. "Compatibility" indicates some measure of compatibility with a parent type, however, sometimes incompatibility existed even within a product family. A "clone" system has identical hardware and is functionally interchangeable with its prototype; a few clone systems relied on illicit copies of system ROMs to make them functional.
List of hobby, kit, or trainer computers.
This type of microcomputer required significant electronics skills to assemble or operate. They were sometimes sold in kit form that required the user to insert and solder components in a printed circuit board. They may have had just blinking lights and toggle switches, or a hexadecimal display and a numeric keypad. While some units were possibly expandable to the "checkbook balancing/homework typing" stage, most were intended more for education on the use and application of microprocessors. See also Microprocessor development board, Single-board computer.
School computers.
These were aimed at the class room, not the living room. Some types were popular in the centrally planned economies of eastern Europe where Western computers were scarce, or in the early days of computer education in Western schools. Popular home computers of the period were fitted with various types of network interfaces to allow sharing of files, large disk drives, and printers, and often allowed a teacher to interact with a student, supervise the system usage, and carry out administrative tasks from a host computer.
Cardboard and demonstrator "computers".
Logic demonstrators illustrated some of the logical principles of computer circuits, but were incapable of automatic operation or non-trivial calculations. Some were literally cardboard, others used combinations of switches and lamps to show how logical operations worked. Some products demonstrated logical operations purely mechanically.


Flicker fixer

A flicker fixer or scan doubler is a piece of computer hardware that de-interlaces an output video signal. The flicker fixer accomplishes this by adjusting the timing of the natively interlaced video signal to suit the needs of a progressive display Ex: CRT computer monitor. Flicker fixers in essence create a progressive frame of video from two interlaced fields of video.
Flicker fixers sample the NTSC/PAL output from the output device and store each scan line from the field currently being displayed in RAM while simultaneously outputting the line alternately with the corresponding neighboring lines from the field stored previously ("weaving"). Some more advanced flicker fixers integrated in add-on graphics cards use more sophisticated methods. Outputting the image at double scan rate essentially composes a progressive display with all lines from both fields at full vertical refresh rate. This promotes the horizontal frequency of the signal from 15.734 kHz to 31.47 kHz (in the NTSC case, numbers for PAL are slightly lower), which can be the used to drive a VGA monitor from an output device.
Use with the Commodore Amiga.
One computer capable of producing an interlaced image is the Commodore Amiga. The Amiga's default video mode is PAL or NTSC. NTSC and PAL interlaced screens have two fields called odd and even. The fields switch every 60th of a second on NTSC, or 50th of a second on PAL, which allows for higher resolution while using a narrower signal bandwidth than full 50 or 60 FPS progressive video would require, but it can also produce an alarming jittering effect for graphics with high contrast details between fields. This NTSC/PAL compatibility gave the Amiga a distinct edge in uses such as television production and gaming, but since the original Amigas were unable to produce vertically high-resolution displays without flickering this was unsuitable for office-like usage where one might need to work with a clear high-resolution image for several hours. Flicker fixers were devised to remedy this.
The later iteration of the Amiga - the Amiga 3000 had a custom chip called Amber which could perform flicker-fixing on any signal. The ECS and AGA chipset could also output VGA display modes. Commodore offered the A2320 Display Enhancer Board for this purpose, The board fit neatly in a video graphics adapter slot on the A2000 series computer. It supported the new video modes offered by the Enhanced Chip Set (ECS) and AmigaOS 2.0, including the Productivity Mode. Also, the earlier A2024 'Hedley' greyscale monitor featured an integrated flicker fixer, supporting up to 8 shades of grey.


Amiga Chip RAM

Chip RAM is a commonly used term for the integrated RAM used in Commodore's line of Amiga computers. Chip RAM is shared between the central processing unit (CPU) and the Amiga's dedicated chipset (hence the name). It was also, rather misleadingly, known as "graphics RAM".
Direct memory access.
Under the Amiga architecture, the direct memory access (DMA) controller is integrated into the Agnus (Alice on AGA models) chip. Both the CPU and other members of the chipset have to arbitrate for access to shared RAM via Agnus. This allows the custom chips to perform video, audio, or other DMA operations independently of the CPU. As the 68000 processor used in early Amiga systems usually only accesses memory on every second memory cycle, Agnus operates a system where the "odd" clock cycle is allocated to time-critical custom chip access and the "even" cycle is allocated to the CPU: thus, for average DMA demand, the CPU is not typically blocked from memory access and may run without interruption. However, certain chipset DMA, such as high-resolution graphics with a larger color palette, Copper, or blitter operations, can use any spare cycles, effectively blocking cycles from the CPU. In such situations CPU cycles are only blocked while accessing shared RAM, but never when accessing Fast (CPU-only) RAM (when present) or ROM.
Chip RAM by model.
Most stock Amiga systems were equipped with Chip RAM only and shipped with between 256 kiB and 2 MiB.
The shared RAM data bus is 16-bit on OCS and ECS systems. The later AGA systems use a 32-bit data bus controlled by the Alice coprocessor (replacing Agnus) and 32-bit RAM. The memory clock runs at double the rate on AGA systems. As a result, chipset RAM bandwidth is increased fourfold compared to the earlier 16-bit design. However, 32-bit access is limited to CPU and graphics DMA and cannot be used for other devices. The ECS-based A3000 also has 32-bit Chip RAM, but access is only 32-bit for CPU operations; the chipset remained 16-bit.
The maximum amount of Chip RAM is dependent on the Agnus/Alice version. The original Agnus chip fitted to the A1000 and early A2000 systems is a 48-pin DIP package able to address 512 KiB of Chip RAM. Subsequent versions of the Agnus are in an 84-pin PLCC package (either socketed or surface-mounted). All models except the A1000 are upgradable to 2 MiB of Chip RAM. The A500 and the early A2000B can accommodate 1 MiB by installing a later revision Agnus chip (8732A) with minimal hardware modifications; late-production machines usually already contained that chip, so that only jumper modifications were necessary. Likewise, 2 MB can be installed by fitting an 8372B Agnus and extra memory.
The maximum amount of Chip RAM in any model is 2 MiB. The Amiga 4000 motherboard includes a non-functional jumper that anticipated later chips and is labeled for 8 MiB of Chip RAM—regardless of its position, the system only recognizes 2 MiB due to the limitations of the Alice chip. However, the software emulator UAE can emulate an Amiga system with the design limit of up to 8 MiB of Chip RAM.
Fast RAM.
Amiga systems can also be expanded with Fast RAM, which is only accessible to the CPU. This improves execution speed, as CPU cycles are never blocked even when the custom chipset is simultaneously accessing Chip RAM. Adding Fast RAM to systems with 32-bit CPUs roughly doubles the instruction speed, as the more advanced 68020, '030, and '040 CPUs can utilize more memory cycles than the earlier 68000.
Confusingly, a system may have several different kinds and speeds of Fast RAM. For example, an Amiga 3000 may contain 16-bit Zorro II expansion RAM, 32-bit Zorro III expansion RAM, 32-bit motherboard RAM, and 32-bit CPU card RAM simultaneously (in increasing speed order). Automatically configured RAM is prioritized by the system, so the fastest memory is used first.
Early versions of the Amiga 2000B, and the most common "trapdoor memory expanded" configuration of the Amiga 500, contain 512 KiB pseudo-fast RAM ("slow RAM") controlled by Agnus with the same limitations as Chip RAM, yet unusable as such due to register limitations. Numerous budget trapdoor expansions for the 500 extended this "controllerless" concept to up to 1.8 MB slow RAM (requiring a Gary adapter for addressing).