wishing to use RSTS 9.6 or earlier for non-commercial, hobby purposes no-cost license. The license is only valid on the SIMH PDP-11 emulator. The license also covers some other Digital operating systems. Copies of the license are included in an authorized software kit available for download on the official website of the SIMH emulator. Documentation The standard complement of documentation manuals that accompanies a RSTS distribution consists of at least 11 large three-ring binders (collectively known as "The orange wall"), one small three-ring binder containing the RSTS/E Quick Reference Guide and a paperback copy of Introduction to BASIC AA-0155B-TK. Each of the 11 three-ring binders contains: Volume 1: General Information and Installation Documentation Directory Release Notes Maintenance Notebook System Installation and Update Guide Volume 2: System Management System Manager's Guide Volume 3: System Usage System User's Guide Guide to Writing Command Procedures Volume 4: Utilities Utilities Reference Manual Introduction to the EDT Editor SORT/MERGE User's Guide RUNOFF User's Guide Volume 4A: Utilities EDT Editor Manual Volume 4B: Utilities Task Builder Reference Manual Programmer's Utilities Manual RT11 Utilities Manual TECO User's Guide Volume 5: BASIC-PLUS BASIC-PLUS Language Manual Volume 6: System Programming Programming Manual Volume 7: MACRO Programming System Directives Manual ODT Reference Manual Volume 7A: MACRO Programming MACRO-11 Language Manual RMS-11 MACRO Programmer's Guide Volume 8: RMS [Record Management Services] RMS-11: An Introduction RMS11 User's Guide RMS-11 Utilities Operation Communication RSTS uses a serial communication connection to interact with the operator. The connection might be a local computer terminal with a 20 mA current loop interface, an RS-232 interface (either local serial port or remote connection via modem), or by an Ethernet connection using DECnet or LAT. As many as 128 terminals (using multi-terminal service) can connect to a RSTS system, running a maximum of 63 jobs (depending on the processor being used, the amount of memory and disk space, and the system load). Most RSTS systems had far fewer terminals. Users can also submit jobs to be run in batch mode. There is also a batch program called "ATPK" that allows users to run a series of commands on an imaginary terminal (pseudo-terminal) in semi-interactive mode similar to batch commands in MS-DOS. Login [Project, Programmer] Users connect to the system by typing the LOGIN command (or HELLO) at a logged-out terminal and pressing return. Typing any command at a logged-out terminal starts the LOGIN program which then interprets the