9 Apr
2002
9 Apr
'02
5:13 p.m.
Interesting, but nonetheless incredibly timewasting
and pointless idea: get an old XT clone with the BIOS
and the 4 blank sockets for BASIC. Write a BIOS
extension chipset in 4 2716's or less. This would be a
great deal of work, though.
You can do this same sort of thing even today if you
have a junky (or not)network card with the net boot
EPROM socket (almost always a 2716/32/64 or similar).
The code doesn't have to have anything to do with a
network. I actually did something like this many years
ago when I wrote a password protection EPROM for my
XT, unfortunately, I don't have the code anymore, but
as I recall the first two bytes have to be 0x55 0xAA
or something similar, and the chip must checksum to 0.
I wrote the code in assembler, reserved a byte for the
checksum, and wrote a BASIC program (no laughing,
please) to calc the checksum and drop it into the
image.
--- Richard Erlacher <edick(a)idcomm.com> wrote:
Why not just build a PROM card? I will happily send
you a blank card with
some decoding logic, buffers, and enough wire-wrap
space for an EPROM or two
for the cost of postage.
Dick
----- Original Message -----
From: "Bob Shannon" <bshannon(a)tiac.net>
To: <classiccmp(a)classiccmp.org>
Sent: Tuesday, April 09, 2002 6:23 PM
Subject: Re: Native CP/M
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I second the request!
I'd love to get a BIOS for my Imsai, but its a
project for another day. A
decent CP/M package would be a great start, but
I'd also need some tiny
monitor
to get code into the Imsai.
I doubt this is a job for the front panel...
Don Caprio wrote:
> I'm trying to build a development platform for
my Imsai. I've tried
various
> CP/M emulators but haven't found one I
like yet.
>
> Has anyone sucessfully run CP/M on a PC without
running under dos and/or
windows?
Thanks.