80-Bus News

2. Weightman & Bullen Architects
23 Front St.,
Acomb, York
Tel ____ ______

would be grateful to hear from other Nascom owners who are using them for Architectural purposes in accounting or Design. Currently we have a Nascom 2, 48K, Nas-Sys 1.

Secondly, in response to Mr. O’Farrells book reviews in 80-BUS News Iss. 1:–

Software Tools in Pascal.

Not having read the original I cannot make comparisons, but I recommend it as being very readable and well illustrated with examples of Programming and Documentation!!!! The cost is quite high (£8.95) but is very good value though the example programs will need rewriting to overcome User definable type limitations on the current Nascom Pascal. Please, please, BLS give us user definable types!

Since I am currently reading ‘Computing Science’ at Imperial College as a degree may I recommend the following books to the interested reader:

Thomas Bartee   Digital Computer. Fundamentals   McGraw Hill   £5.95
Thick, cheap, informative, lots of diagrams and examples of “Real” machines.

Martin Cripps   Introduction to Computer Hardware   Arnold   £4.75
A less detailed view than Bartee but very readable and a good insight into “How it Works”

Further to comments on “Algorithms & Data Structures” by N Worth Prentice Hall.
Gemini’s disk version of Comal-80 contains a Comal version of the Pascal PL/0 compiler described in the book.

Thirdly. A Virtual Nascom??
Is this possible/​feasible??

1. Tape routines for Nascoms/​Geminis to read each others formats. Both use 1200 baud CUTS, but as yet I don’t know how the RP/M routine works.

2. More Important. Video RAM Interrupt board. Is it possible for a board (ie 80-BUS) to be built that detects when a certain portion of memory is being read and then interrupts the host processor. This should really be user definable in 4K blocks a la N2 restart jump. Port addressing could be used to enable/​disable this feature. For true N2 emulation the board must produce interrupts for memory writes between 0800-0BFF.

With this board in a Gemini type system, Nascoms with video RAM could be emulated fully enabling ZEAP, Naspen, Nas-Dis, Space Invaders, Pirahna etc. to be used and give full compatibility between both computers.

C’mon hardware hackers, someone design the circuitry and I’ll write the software if it proves feasible.

Rupert Brown, Nasfan, Nascomaniac and Gemini owner, York.

[Ed. – Did you not see the routine published by R. Beal in INMC80? This allows the Gemini IVC to be used in a pseudo memory-mapped manner. Plus, I hear rumour (from Holland) that there is a program going around that allows most Nas-Sys programs to be run under RP/M and use the IVC for output, even when the output is done directly to a Nascom screen RAM address!]