Microsoft open sources GWBASIC

Liam Proven lproven at
Thu May 28 14:25:22 CDT 2020

On Thu, 28 May 2020 at 21:11, geneb <geneb at> wrote:
> CP/M was huge in the US, especially among the S-100 system users.  It was
> a pretty narrow window though - from probably 1978-1982.  Kaypro had a
> good portion of the market as well, but like pretty much all the other
> manufacturers of CP/M machines, the IBM PC compatible juggernaut beat them
> cold before they fully understood the fight.  I'm not aware of any CP/M
> machine manufacturer that was able to successfully transition to the PC
> compatible market.  Some (like Kaypro) tried with offerings like the
> Kaypro 16 and Kaypro 2000, but I suspect at that point it was too little,
> too late.  They simply couldn't compete with the uber cheap hardware
> coming in from overseas.

The $64K question is, of course, how big that market was.

I was reading computer magazines back then, but I didn't have one for
a good while. I was aware of the prevalence of CP/M, sure. But I was a
kid -- 12 at the end of 1980 -- and not interested in business/office

I have no idea if many UK offices or businesses were using CP/M
computers. I wouldn't have paid much attention if I saw them, but I
don't remember seeing many.

I know when I entered the business, in 1988, some companies had old
computers around, sure. Very early PCs, including clones from Epson
and Sony and so on, and a few things like Apricots and Victors running
DOS but not PC-compatible. I saw a handful of minicomputers -- one
PDP-11, one IBM S/36 and one AS/400 in that job; the next AS/400 being
about 15y later in 2002.

One company sold computers that ran an OS _called_ CPM-something, but
it wasn't CP/M. I am not in regular touch with anyone I worked with
back then to ask, sadly. They were big chunky desktops with screen
built into the case, an 8" floppy and an 8" or even 12" hard disk.

I has used  DR CP/M and this was utterly different. I don't think it
had a microprocessor at all. I have asked on the list before and never
found out any candidates for what it might be.

I did one job extracting data from a laboratory  BBC Micro-based
system with a Torch "bridge". BBC Micros were a big desktop slab --
the classic all-in-one keyboard and system unit, but the back was a
foot deep so big enough (but *not* strong enough) for a CRT to sit on
it. So serious users got a 5¼" drive in a metal chassis that went over
the back of the computer and was strong enough to sit a CRT on top.

Like this, but on legs to go over not under the computer:

It turns the 6502 Beeb into a Z80 CP/M machine.

They had both CP/M files (trivial to convert) and BBC files (_not_
trivial and took us some work).

I think in my first decade at work, that is the only time I ever saw
an old DR CP/M system -- but I came in about a decade after CP/M's

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