30 Oct
2004
30 Oct
'04
3:07 a.m.
Yeah, that white MDS-800 is the first I've seen as well. Very cool, I
think.
As for the BIOS in CP/M, it is actually not much different between the
SD and the DD controller boardset. They take the exact same command
set, as I remember. The only real difference is the range of sector
numbers, as there are merely more sectors on the DD diskettes. The
sectors themselves are the same size. They used different I/O ranges
for the control ports, but that was about it.
The original DRI CP/M-80, right out of the box from Digital Research,
would boot on an MDS-800 with the SD controller boards. That is the way
an OEM would get it and they would rewrite the BIOS for their hardware.
Kildall wrote the original CP/M for that exact system, the MDS-800
with Single Density controllers (the SBC-201).
I did a lot of rewriting on my version of the BIOS in order to handle
the internal SD drive on a Series II as a fifth drive (the first four
were the ones that the SBC-202 DD controller could handle). The CP/M
that I bought from Intel supported having BOTH the SD and the DD
controllers in the system at the same time, but Intel never supported
CP/M and the internal drive on the Series II.
Dave
Joe R. wrote:
That's interesting. I've never even heard of
a white MDS-800 before. Was
it painted white originally or was it painted over an orginal blue one?
I think you need a lot more than rewriting the BIOS to handle DD disks.
Intels DD controller has a 3000 series bit-slice CPU and some other odd
circuitry to handle DD.
Joe
At 11:39 AM 10/29/04 +0200, you wrote:
I have a white MDS 800 System. It was sold in
Germany by Siemens and they
relabelled it to SME 800 ("Siemens Microcomputer Entwicklungssystem").
It has an external 8"-double drive and a dumb terminal. Inside it is all
Intel. The only thing they changed internal: The glued "Siemens"-labels
over the original Intel-logos on the PCBs.
You can see it:
http://computermuseum-stuttgart.de/dev/sme800
We are running ISIS-II inclusive KERMIT on it. One time Christian Corti
succeeded to boot a CP/M 2.?. But in the meantime this disk was damaged.
I found a very old CP/M source, dated "11/21/75" in the net, written in
PL/M and was able to translate it with the original PL/M-compiler
written in FORTRAN (dated: JAN 1975) on our SUN 4/260.
What is needed: To adapt the original BIOS for single density disks to
the double density drives on our system and to make bootable floppies.
Cheers
Klemens
On Wed, 27 Oct 2004, Steve Thatcher wrote:
>I lived in Munich, Germany for a year and a half back in 1983 while I was
>working for Applied Microsystems. I developed a couple of the EM series
>emulators and ran into a number of remarked Intel systems that said
Siemens
on the
outside.
--
klemens krause
Stuttgarter KompetenzZentrum fyr Minimal- & Retrocomputing.
http://computermuseum.informatik.uni-stuttgart.de
I've never heard of a Siemans system. The
white MDSs that I've seen all
have the standard Intel markings and labels. (I've got one sitting about 3
feet from me as I type.)
Joe