Mail Archives: opendos/2000/07/17/17:13:17
> Kildall was also stubborn about pricing -- at the
> time, CP/M was *the* brand for serious microcomputer
> operating systems, and Kildall *vastly*
> underestimated the power of IBM to establish a new
> rival brand overnight.
Well, I can see his point - IBM were somewhat late in joining the game, and
stayed quite a distance behind the competition for many years. It was a
somewhat short-sighted decision not to sell at MS's price, although
hindsight is always 20/20...
> Gates was much smarter
> about the situation, foregoing the per-unit $$
> and realizing that time-to-market was much more
> important than delivering quality code in 1981.
Oh, how much MS have changed. They don't even care about time-to-market now
:)
> > Well, yes, but QDOS was pretty much a disassembly/reassembly of
> > CP/M-80,
> > wasn't it?
>
> There's quite a debate about that, it surfaces
> from time to time on the comp.os.cpm newsgroup.
Whoa, it's been a long time since I read that 'froup...
> As a DRI OEM, Seattle did have access to some DRI code --
> I suspect what they did was more of a functional clone
> (sort of like the first Phoenix BIOS was a functional
> clone of the IBM PC-XT BIOS) than "disassembly/reassembly."
In much the same way we now have wine as a Windows clone etc. I suppose.
It's possible, although my QDOS disk suffered from the bit rot around 1987,
so I never got a chance to compare it to my CP/M disks.
> CP/M 2.2 (the first popular version) didn't have any
> CPM.SYS except perhaps as an intermediate system image --
> the three modules, BIOS (from the hardware manufacturer),
> BDOS, and CCP (from DRI) were loaded from dedicated "system
> tracks" on the floppy (and later hard) disk.
Yes, of course, I remember reading those parts of the source and thinking
'weird way of doing things', but I suppose no weirder than any other. I'm
half asleep this evening - keep getting CP/M, CP/M-86, DOS Plus, and my
Apple ][ mixed up. The Apple ][ had a Z80 card with a disk containing a
'CPM.SYS' file, but perhaps that wasn't the OS after all. It was CP/M 2.2
though.
> For CP/M 2.2, the system image was created
> as a binary file (essentially a concatentation of the BIOS,
> BDOS, and CCP binaries as they were to reside in RAM,
> with BDOS and CCP being of fixed size from DRI) and
> transferred to the system tracks with a hardware-
> specific "SYSGEN" program.
And CP/M 1 required one to do that all by hand, according to the bits and
pieces I've collected in my DOWNLOAD directory over the years. Ah well, I
suppose asking each OEM to patch the OS by hand would be asking a bit too
much these days :)
> The most remarkable thing is the tiny size of the
> code in those days
It's amazing really - even modern assembly programs don't seem to be as
tightly coded. However, working with DRI's rather frugal programming
environment (I'm a developer on the FreeGEM project), it's not surprising
they managed to pack it in so small a space. If the GEM Desktop code is
anything to go by, there are probably some crafty little tricks in there.
> Now that everyone and his granny has
> more RAM than an entire shop of CP/M coders, all in
> a single cheap PC, I guess that level of the coding art
> is lost forever.
This morning I had to sort out a pile of machines at work, and some of these
had labels I don't remember writing (distinctive handwriting though,
definitely mine) marked 65Mb, 128Mb etc., and I thought 'what are these
machines doing with 64Mb RAM? I'll have some of that' - and then I realised
they were harddrive capacities. Heck, I've enough RAM in this machine to
store the entire contents of my main HDD from four years ago, and 12 copies
of my first HDD. But I digress. I wonder what Gary Kildall would think of
modern desktop machines?
> I've never heard of "CP/M 4," and I was intimately involved in
> the 8-bit CP/M world throughout the '80s. What did I miss?
Sorry, missed off a '-86'. I'm not sure if it existed as CP/M, but it's the
OS inside DOS Plus (Cp/M-86 with a DOS 2 emulation layer) and Personal CP/M
(that seems quite interesting - it's the only CP/M I've found that'll boot
correctly on my P][400). John Elliott's website had some info on it -
http://www.seasip.demon.co.uk/. But I see John's just pointed this out :)
*sigh* I must drink more coffee, I had MP/M and CP/M-86 confused for a
moment.
Regards,
Ben A L Jemmett
(http://web.ukonline.co.uk/ben.jemmett/, http://www.deltasoft.com/)
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