Micro­power

  

Volume 2 · Number 4 · September 1982

Page 14 of 36

Making a Nascom 1 into a Nascom 2 – so to speak

P. Crabb

This application note is intended as a guide for any soldering iron freak who happens to fall into the same way of thinking as myself. I will not guarantee that what has been accomplished on my system will work nor that it will not destroy what you have scrimped and saved lovingly to build over the last seven or eight years.

The Nascom 1 is an excellent machine even without the addition of Nas-sys, and a lot more powerful than many people realise, but in the light of the Nascom 2, it has somewhat paled, although with the time and effort lost in the ‘bankrupcy’ period, the total system has somewhat paled in the light of what you can now get for the same cost. In defence of the concept, I must add that what you lose in getting a complete working system from another source is more valuable to me than the money saved, but then I am funny that way. You probably are too.

I acquired my Nascom 1 many years ago and it served several purposes before being consigned to its box to gather dust while I set to work (paid) an a number of different systems. My work eventually moved on to the Nascom 2 as a base for an o.e.m. learning system and interest in the Nascom 1 was regenerated to the extent of acquiring a buffer board and a 16K RAM card.

During my original researches with the Nascom 1, I had expanded to the extent of CCsoft Tiny BASIC which I fitted to the standard machine using the Bits & P.C.s dual monitor board and I must commend this (if it is still available) to anyone who wants a cheap training system for BASIC. But, although I wrote a large number of useful programs (like calculating Pi to several thousand places) with the unexpanded Nascom/​CCsoft system, the prospect of having so much extra storage did not appeal to my pioneering spirit, and I looked for a better vehicle to explore the wide-open spaces.

The answer was abviously the ROM BASIC from the Nascom 2 and  ,​quite by chance, one became available. as did a Nas-sys ROM. This was quite legal, decent and almost honest since when I bought a Nascom 2 CP/M system these were on the board, and in the price, but quite inaccessible on the memory maps.

The problem was incorporating them into the system. There were definitely no funds available for an EPROM board, and even if there had been, there would need to be modifications before the ROM BASIC could be accomodated. The answer to the problems came in a flash of inspiration (and a pool of perspiration) and used the Dual Monitor board.

Here there are four 2708 sockets, each providing access to the data bus, most of the address bus and also power lines.

Page 14 of 36