International Computers Limited - 2903 Range

2903 Range

A rapid development to produce a small business computer from, as far as possible, existing hardware and software. It was urgently needed to generate a cash flow that would support continuing 2900 development. The hardware was based on the 2900 DFC (Disk File Controller), and used the MICOS engine. The 2903/4 system cabinet housed the MICOS engine, Drico FEDS disk storage and an absolutely terrible punched card reader. On a wing attached at 45 degrees there was the operators console which was a visual display unit (VDU). For 1900 users who were accustomed to the Westrex teletype as console this was a major advance. The printers abutted to the wing and were initially integrated, much of the logic was held in the system, soon substituted by the CPI shuttle printer and PBS but maintaining their position.

The 2903 used microcode to emulate 1900 hardware. The operating system was George 1* (a modification of George 1S batch operating system) running on top of the UDAS Executive. In consequence, all the normal 1900 compilers and utilities ran on the 290x range without any changes or recompilation.

One major new facility provided on this range was Direct Data Entry, a system comprising up to eight dedicated VDU data entry stations, with which card image files could be created; these could be assigned to a program's card reader and processed accordingly.

There were three models in the range:

• 2903
• 2904
• 2905 (limited and was replaced by the 2950)

290x computers would run in an office environment, still quite an innovation for this class of machine, and were a runaway success. Roughly 3000 systems were sold. This was ten times as many as ICL had anticipated.

• ME29

The smaller machines in the 290x family were replaced in 1980 by the ME29 system.