fpcsdb

This was an interesting board. Running vertically, approximately 2/3 of the way across, is a NAS-BUS connector. The right-hand end of the card has a connector which suits the NASCOM-1. So, the right-hand side of the board simulates the NASCOM Buffer board and the left-hand side is a large expansion board.

The clever part is that, before fitting the NAS-BUS connector, it is possible to cut off the buffer board part and use the remainder plugged into a NAS-BUS system! Thus we have a dual purpose expansion system. Possible arrangements for connecting to a NASCOM-1 are shown in the drawing below:

The buffer part of the board had a few additional advantages over the standard NASCOM offering:

synchronised power-on reset pulse generator
2716, 2732, 2764 or 8k BASIC ROM socket and decoding
power-on/reset jump to any 4k address boundary
wait-state generator
better I/O port decoding

This was in addition to its normal buffering function.

The remaining part of the board, used by NASCOM or 80-BUS systems, contained the following functions:

64k dynamic RAM with addressing and control logic
programmable graphics system

This was rather neat! It combined just about everything that the NASCOM-1 user needed to upgrade his system to compete with the NASCOM-2 in facilities, if not in speed. Unfortunately the majority of NASCOM-1 machines would not run at 4MHz. With this and an EPROM card quite a powerful (for the period) machine could be assembled. About the only item missing was a good cassette interface, but most NASCOM-1 users had already built/bought the Cottis-Blandford board so its absence from this card was not severely missed.

The programmable graphics system gave 128 user-defined characters with the possibility of a further 128 "bank-switched" as a second user-defined set. Although not the true high resolution screens that we are accustomed to today, this was extremely useful.

The board was sold without components as several construction variations were possible. Micro-Power advertised it 1n 1983 for 39.5 UKP plus carriage and VAT. I can speak from personal experience, this card was one of the best things to appear for the NASCOM-1 owner!