80-Bus News


September–October 1983, Volume 2, Issue 5

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the licensee (i.e. the manufacturer) is concerned he can NOT get any price concession on a CP/M Plus license from Digital Research unless he ‘trades-in’ his CP/M 2 license. This ‘all-or-nothing’ situation means selling ONLY CP/M Plus’s with his systems (and having to put up his prices to cover it), or having to buy a CP/M Plus license as well (and having to put up his prices to cover it)! Finally, CP/M Plus is available in two versions – one for systems with 64K RAM or less, the other for more than 64K. From what I know the first of these is of little practical benefit, as you don’t get the main features that CP/M Plus is all about – cache buffering etc; you do however lose more TPA (available RAM, to you and me!) because of Plus’s greater size. With the latter version you get hit by cost again – the system needs additional hardware (e.g. more RAM, plus a Real Time Clock) to support all the extra features, and hence must cost more. I am sure that CP/M Plus has some features that we would all love, but, in my opinion, it either needs Digital Research to alter its pricing philosophy, or YOU, the customer, to say to Nascom, Gemini, or who-ever “Of course T’d buy lots more boards and things, if only I could have CP/M Plus.” Personally I. don’t think it’ll catch on – and I very rarely make such statements in print, as I would hate to have my own quotes flung back at me at some future date! There is one possible exception to my opinion – see below.


As to the question of CP/M Plus SYSs, my understanding of Plus is that it is constructed in such a way that a well written BIOS can have additional facilities added WITHOUT having to have the BIOS source code, or in fact any other ‘tools’ than those supplied with Plus. For example, manufacturer X brings out a 1 gigabyte bubble memory board. With it he supplies a disk that contains code that is easily linked by the user to his CP/M Plus, providing instand giga-memory! Too easy to be true? Not according to an emminent Nascom/​Gemini systems software writer – not named in case he’s wrong!


Z800 CPU card? Fantastic idea! One snag! Contact Zilog USA, find someone who knows what’s going on, and ask him when there will be real production devices around in anything more than handfuls. If he says 1984 you’ve got a salesman, not a realist; try again! The Z800 sounds a super device (in fact ‘Z800’ is a generic term referring to any of the four quite different versions that there will eventually be). For those who haven’t heard of the Z800, and without going into any detail, it is a super-charged, turbo-charged, fuel-injected Z80 with cache buffer, extended addressing range, and additional instructions. Further description can wait a few months, maybe even a year! Going back to my comments on CP/M Plus, it is in fact the Z800 that causes me to add the qualifier. The combination could be extremely powerful and fast. But we must dream, and wait…

Source listings.

I am sure that your comments on pricing will be noted, although the important thing to note is that the listings are available if you want them, even though it’s at a price! Since Lucas bought Nascom I don’t think that any of the new products have come with listings – for example, the AVC hasn’t – see Dave Hunt’s review in the last issue, nor has their disk system. Gemini supplies sources of one or two minor utilities and demos, and used to supply BIOS listings. My knowledge of other manufacturers is limited, but I am not aware of any that DOES supply sources, other than MAP80 – and that is currently the subject of High Court proceedings which are being brought against MAP80 Systems by Gemini Microcomputers for alleged copying by MAP80 of large portions of the Gemini BIOS. Selling source listings instead of giving them away obviously doesn’t guarantee that they won’t still be copied, but the

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