80-Bus News


Spring 1985 · Volume 4 · Issue 1

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hand if need be. The program fulfilled its main purpose, and the backup disks are made using the separate BACKUP program which had been used previously.

Nascom — Where now?

Fairly regularly people walk in the shop and say, “I’ve got an old Nascom 2 and don’t know whether to get rid of it or spend some loot and upgrade it.”. Well two things are apparent, firstly there are a lot of Nascom 2’s still around (there should be, as nearly 10,000 were made before Lucas got there paws on the show), and secondly a lot of people are still dedicated to the machine which in all probability they sweated blood over building some three or four years back.

The problem is doing anything with a Nascom works out expensive. Possibly the cheapest way out is to flog the Nascom to some unsuspecting mug and then go and buy a Beeb, a Spectrum, a Commodore or some other such Mickey Mouse computer. But then none of these has the potential of an expanded Nascom, despite the plethora of add-on bits you can get for them.

All the following comments apply equally to the Nascom 1, but remember that for optimum results the N1 should be capable of running at 4MHz (although the disk systems will run as slow as 2MHz with no wait states) and the N1 should have a decent buffer board. The original Nascom buffer board wasn’t too clever! The Gemini GM806AK combined backplane-cum-buffer board is fine. (This IS still available, so don’t believe any dealer who says he can’t get it for you anymore.)

The only viable upgrade of a Nascom is towards disks, a goodly few have already taken that course, and I think those who have gone that way are happy. Expensive certainly, but still worth the money as the end result still costs less than going out and buying an equivalent machine from new. However, even this route is becoming more circumscribed as Lucas seem to contract their Nascom operation and Gemini have reduced the number of options available. MAP are still around and in there somewhere, but I haven’t heard from them for some time.

All permutations would need at least 48K of RAM and all would require disk drives. The drives would be either single or double sided 80 track drives. The drive boxes available from the various 80-BUS manufacturers are all comparitively expensive, and cheaper equivalents can be found advertised as options for the Beeb computer. But watch the specs. Check that what you are buying does or does not include power supplies (as required) and that 40/80 track types are really 80 track types and not some ‘cod’ used by the various DOSes for the Beeb.

The basic choices left are:

  1. Nascom NASDOS with the Nascom controller card, with or without the AVC card.
  2. Nascom CP/M with the Nascom disk controller and AVC cards.
  3. Gemini CP/M with the Gemini disk controller and IVC or SVC cards.
  4. MAP CP/M with the MAP VFC disk controller/​video card.
  5. Careful permutations of 3 and 4.

Choice 1) Uses the original Nascom screen display and needs the Nascom disk controller card. It may well not be the best choice, for although NASDOS allows the use of your original Nascom software, little if any new software has been made available.

Choice 2) Uses the original Nascom screen display and needs the Nascom disk controller card. Not a bad choice, CP/M 2.2 seems to be the route to take. The Nascom CP/M uses the Nascom AVC as either a colour display or as an 80 column display (very necessary for CP/M). The Nascom AVC is a bit slow in the 80 column mode.

The problem with either choices 1) or 2) is likely to be support. Most of Nascoms’ old faithful dealers now no longer stock Nascom products and Lucas do not seem to be encouraging new dealers. The only dealer (as far as I am aware) able to offer full support for Nascom products these days is B & L Micros at Kenilworth. So unless you live in the Midlands, the Nascom options might not be advisable.

Choice 3) Uses the Gemini GM829 disk controller card or the (now obsolete) GM809 card. Possibly the most universal choice. There were more Nascom/​Gemini hybrids in the recent 80BUS survey than anything else except straight Gemini systems. Gemini have recently reduced the permutations of CP/M 2.2 for Nascom, so the only version currently available uses single or double sided 80 track drives and must use either the Gemini SVC or the (now obsolete) IVC card. This makes it the most expensive choice, but it wins on both overall operating speed and disk capacity. You could save money by using secondhand GM809 and GM812 cards as these still seem to be around in small quantities from people who have upgraded to GM829 and GM832 respectively.

Choice 4) Uses the MAP VFC combined video and disk controller card. Available with either CP/M 2.2 or CP/M 3. (None of the other manufacturers have opted for CP/M 3 as there is little to show for the increased cost.) About the same price as the straight Gemini choice using secondhand cards.

Choice 5) Careful permutations of Gemini and MAP cards with a suitable choice of CP/M (Gemini or MAP, depending upon the exact permutation) will work but there seems no advantage in opting fora

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