The Rockwell AIM 65 computer was a development computer based on the MOS Technology 6502 microprocessor introduced in 1976. The Rockwell 6502 processor ran with a clock speed of 1MHz and an 8K monitor in ROM plus 1K of user RAM. The user memory was expandable on-board to 4K. The AIM-65 was essentially an expanded KIM-1 computer. Available software included a monitor with line at a time assembler/disassembler, BASIC interpreter, assembler, Pascal, PL/65, and FORTH development system. Available hardware included a floppy disk controller and a back plane for expansion.

The AIM 65 (R6500 based Advanced Interactive Microcomputer) retailed at $375/£249.50. The fully-built and tested single-board computer came complete with full 54-key QWERTY keyboard, 20-character LED display and 20-column printer which used thermal roll paper and produced characters formed in a 5 x 7 dot matrix operating at 120 lines per minute. The computer has extensive options, many interfaces and expansion capabilities. The AIM 65 is also a mini-development system at the price of most evaluation boards. In addition to bare board blue-collar versions, the AIM 65 is available in an enclosure, complete with power supply, for use as a desk top computer. 

Standard software included the system console monitor software in ROM, called Advanced Interactive Monitor. It featured line assembler, disassembler, setting and viewing memory and registers, starting execution of other programs and more. Single stepping was made possible using non-maskable interrupt (NMI). The command prompt was the less-than sign "<", and on receiving a single character command, it added this input character and the greater-than sign ">". If the thermal printer was turned on, this would be output on a single line. The monitor included a number of service routines that could be accessed and used by a user's program to control I/O and code execution, and was fully documented, including source code.

An audio cassette interface programmable for two tape recording formats was provided; one at a standard 1,200 baud and the other at a Kim-1 compatible version.  This made it possible to write large assembly programs using the two pass assembler ROM. Source code in text was written twice consecutively to the input tape, and then the assembler, which could start/stop the input cassette tape using motor control was invoked. During the first pass the symbol table was built and stored in RAM. During the second pass symbols would be translated and code written out to the second tape, also using start/stop motor control. Being able to avoid storing code in RAM made it possible to save much space. It was however, still important to keep the symbols list short since RAM size was often no more than 4 KB.

There are 5 ROM sockets available for program installation, but 2 of them are normally occupied by the Monitor/Text Editor. The Monitor can be considered the Operating System, since it provides the over-all system control. 

The three remaining ROM sockets can be used for user-defined programs to be installed. BASIC, PASCAL, FORTH, or an Assembler/disassembler can also be installed, although the PASCAL ROMS require an additional expansion module. 

The AIM 65 can directly interface with external peripherals with its two 8-bit bi-directional parallel ports, a 9600 baud serial port, 4 control lines, and 2 timers.

Manufacturer: Rockwell
Date: 1976

This exhibit has a reference ID of CH25227. Please quote this reference ID in any communication with the Centre for Computing History.

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