80-Bus News


March–April 1983, Volume 2, Issue 2

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tapes and disks live in the drawers and all the manuals in the cupboard (and these days in the filing cabinet as well). The computer is safe and away from prying fingers, being buried on the shelves behind the desk. The only snag as far as I can see is the weight of the thing, like all MFI stuff, it might be cheap, but it makes up for it in weight. With the cupboard full of books, the keyboard, monitor and printer in place, and the drawers full, it must weigh nearly a couple of hundredweight, a distinct disincentive to making changes to the computer as it means pulling the whole lot away from the wall to get at anything.

With the advent of the disk system, so CP/M came into my life. This proved to be quite useable but a lot less clever than the nice Nascom operating systems Richard is wont to write. Richard converted to CP/M about the same time and started to write the SYS series of overlay BIOSes for CP/M which brought some of the niceties of NAS-SYS to CP/M. Of course, with the advent of disks, everthing I had previously developed as a discipline in using the machine had to change, and with it the sort of things I was doing. Less learning ‘how to use’ the machine and more actually ‘using’ it, if the difference is discernible. Exercises in overlaid BASIC programs for business use, and of course a lot more writing both for this magazine and others using newer and ever improving versions of NAS-PENs.

Despite the danger of my having to wear a truss through moving the desk, the system has grown over the past couple of years. Various goodies from the Gemini range have been added, the GM809 disk controller, doubling the density of disk system, and the Gemini GM812 IVC card, bringing the video display up to the standard I required. I would have liked to have played around with colour, but the Nascom AVC was delayed so long, and when it finally arrived was found to be too slow for my purposes, my enthusiasm waned and I asked myself if the investment in colour was really worth it for the sort of things the computer is used for Pluto would be nice, but prohibitively expensive when the cost of a high resolution monitor to do it justice is considered. So colour was dropped.

With my re-awakened interest in radio (hardly a new found interest as I have been dabbling with radio for the past 20 years, long before the home computer was ever thought of), the need to quieten the system RF-wise became a pressing consideration. For those not aware of the problem, try putting a portable radio next to your Nascom and see what happens (to the radio that is). The radio becomes unuseable except as an uncontrollable squawk box, emitting squeaks and whistles all over the place. Now ALL computers chuck out RF interference and Gemini are as bad as Nascom in that respect. Anyway, the system had to be rebuilt into a totally shielded RF proof box. Up until then it had been what you might call a ‘distributed system’, with bits of it on various shelves. Unfortunately, when designing the box, and bringing it all together, it was soon realised that using the Nascom with its 12″ x 8″ board would mean that the box would be too big to fit on the shelves of the desk. So somewhat reluctantly the Nascom was pensioned off and a Gemini GM813 put in its place. This meant a spare RAM card which could be used as virtual disk as this feature had recently been added to SYS.

So the system slowly evolved and was used under CP/M, using two drives. The A: drive always containing what I called the ‘system disk’, of which I had three. The first ‘system disk’ had all the utilities I used for assembler programming, the assembler and linker, the debugger, PEN, and so on. The second disk had all the BASIC bits on it, the BASIC itself, the compiler and so on. The third disk was my INMC/80BUS (word crunching) disk, containing PEN and the proof reading program SPELLGUARD with its 150K dictionary [Ed. – you trying to tell me you actually ‘Spellguard’ this lot?]. Work was always carried out on the B: drive, and various ‘system disks’ were used in drive A: in conjunction with the relevant ‘work disk’ in drive B:. I have found this an ideal way of working and saw little reason to change it.

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