new find: an Intel MDS 800

[Dave Mabry]

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.
>>>
>>>
>>>
>>>>   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
>>>
>>--
>>
>>klemens krause
>>Stuttgarter KompetenzZentrum fyr Minimal- & Retrocomputing.
>>http://computermuseum.informatik.uni-stuttgart.de
>>
>>
> 
>