Bit of CP/M trivia needed

[Joe R.]

At 02:29 PM 8/30/05 -0700, you wrote:
>>From: "Allison" <ajp166 at bellatlantic.net>
>>
>>>
>>>Subject: Re: Bit of CP/M trivia needed
>>>   From: "Dwight K. Elvey" <dwight.elvey at amd.com>
>>>   Date: Tue, 30 Aug 2005 10:14:15 -0700 (PDT)
>>>     To: cctalk at classiccmp.org
>>>
>>-------snip---------->
>>
>>>>    I don't think so. CPM was first written by Gary Kidall for the Intel
>>>>MDS-800 (go read the CPM docs) and they NEVER had DMA capability. They
used
>>>>a 2k bit bootstrap loaded in a 1702 EPROM. Here is a picture of a MDS-800
>>>>with THE actual 1702 Boot EPROM
>>>
>>>Hi
>>> Yes, what I meant to say was for the S-100. I was told that the first
>>>S-100 implementation used this type of board. I knew Gary used a
>>>MDS-800.
>>>Dwight
>>
>>No.  Most (if not all) of the first S100 system had front pannels 
>>(ALTAIR AND IMSAI Were the first!).  The few that didn't had some form 
>>of rom monitor to simulate a fronpannel via TTY such as Poly-88, 
>>Processor tech SOL and others.
>
>Hi
> What does a front panel have to do with what I stated?


   I think her point was that machines that didn't have any ROM in them had
to have a front panel (in order to handload the boot code)* and that the
later machines contained ROM so a front panel wasn't necessary.  

   *This is how the first Altairs operated. FWIW Later you could buy an
EPROM card for them that contained the exact same code in EPROM and boot
from it.


> I am familiar with the MDS800 having worked for
>Intel and written both assembly and PLM80 for it.
>I was also responsible for testing of the 1036 card
>( the PLL used in the M2FM board set ). So, I do understand
>the disk I/O of the MDS800. I made no claim as to
>how a MDS800 works( please read previous mails ).
>As I corrected, I was not intending to make a claim about
>the first ever CP/M ( again please read previous mail in
>context ) but felt that from the context of the conversation
>that we were talking about S-100 machines. I tried to clarify
>this misconception that I was talking about the MDS800 in
>a previous mail ( again please read ), I was not talking about
>the MDS800.
> All I'm saying is that I was told that this particular
>DMA based interface was used for the first implementation
>on the S-100 of CP/M.

  You may be correct but that's not what the original poster asked and I
think your response confused everyone.

    Joe

 This was told me by another fellow
>many years ago. I don't recall the fellows name but he
>seemed at the time to be honest enough since he had nothing
>to sell or gain by such a comment. He claimed to have some
>involvement in that process. If you don't like that you
>can just shoot me and be done with it but, please, don't
>put words in my mouth.
>Dwight
>
>> 
>>I have the history of being Altair owner SN00200 an early one with a 
>>full set of warts and germs.  I was in the unenviable position by the end of
>>January 1975 of having an assembled and debugged machine with 4k and NO
>>software.  Needless to say I was very heads up for software of any kind. 
>>
>>>><http://www.classiccmp.org/hp/mds-800/frnt-pan.jpg>. The 1702 is mapped
>>>>into and out of the memory space by the BOOT switch on the MDS front
panel.
>>>>Allison's description is dead on. 
>>
>>Should be with the hours spent using MDS800 and having one they are
familiar.
>>
>>>>Dave Mabry is the expert of the Intel MDS
>>>>and he can provide more details about how they're booted and the BIOS
table
>>>>is loaded. FWIW Gary had a contract to write PL/M for Intel and wrote CPM
>>>>as a file handling system for use in developing PL/M. He offered Intel CPM
>>>>but they didn't want it since they were working on their own OS.(BIG
>>>>Mistake!) Intel's OS was released as ISIS and was only used in the Intel
>>>>MDS systems (although I've heard they did have a PC version for a PC based
>>>>MDS). ISIS is very crude compared to CPM.
>>>>
>>>>   MDS 800  <http://www.classiccmp.org/hp/mds-800/mds-800.htm>
>>>>
>>>>   You might also want to take a look at 'CP/M and a brief history lesson'
>>>>here;  <http://www.classiccmp.org/hp/mds/mds.htm>. I used to have the
exact
>>>>quotes from Gary but unfortunately the link to them is now dead.
>>
>>Good synopsis.
>>
>>Allison
>>
>>
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>
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