Rockwell Aim 65
The Rockwell AIM-65, introduced in 1976, is a MOS Technology 6502 microprocessor-based computer designed for training and development. The AIM-65 was the big brother of computer KIM-1. Available software included a monitor with assembler / disassembler of a line at a time, interpreter BASIC, Assembler, Pascal, PL/65 and development system FORTH. Available hardware included a driver diskette and a motherboard for expansion.
The standard software included the monitor in ROM called Advanced Interactive Monitor (AIM) - hence the name of the system. The monitor provided a line assembler, disassembler, ability to modify and view the contents of the memory and registers, initiate the execution of other programs and more. The stepping was possible using the non-maskable interrupt (NMI). The command prompt is the "less than" symbol, "<". If the thermal printer is on, would write characters on one line. The monitor included a number of service routines and was fully documented, including source code.
The machine offered a double ribbon control. This allowed to write large programs in assembly using the two-step assembly in ROM. The source text is written twice consecutively in the input tape, and the assembler was invoked. This could start and stop cassette tape input using motor control. During the first step, the symbol table was made and stored in RAM. During the second step the symbols and the code would be translated into machine language written in the second tape, also using motor control. Being able to avoid storing the code in RAM made it possible to save memory. However, it remained important to keep symbols short since the size of RAM in these machines is often not more than 4 KB .