ISO: Motorola MDP-1000 info/software

Antonio Carlini a.carlini at
Wed Sep 30 13:06:49 CDT 2020

On 30/09/2020 18:40, Josh Dersch via cctalk wrote:
> On Wed, Sep 30, 2020 at 5:20 AM ED SHARPE via cctalk <cctalk at>
> wrote:
>> whats  the  story on  this...i  see  items   but no pix. also   check
>> your  spelling on Motorola; Instrmentation and Control, Inc.  that  is  in
>> the  index. let me  now  if  there  is a photo  group  for this at  least
>> with the  covers   I always  wondered if it  was  just  a  12 bit  computer
>> or  if it  was   software  compatible  with pdp-8? I wonder  what  else
>> this  division of Motorola produced....   there  was a  teleprinter   they
>> made...   Here is  the link  to the  teleprinter  it  is  filed under gov
>> div.  think i got the  12
>> bit  computer manual  from same person.
> The link is dead (seems misspelled, but even correcting it (and changing
> htmi to html) doesn't result in a link that works).  I can't find any
> reference to you posting a link to the manual in the cctalk archives, but
> that doesn't mean it isn't there, somewhere.  If you're able to scan this
> manual, I'd love a copy.
> The MDP-1000 is in no way like a PDP-8.  Different memory word-size, has an
> actual ALU, 5 registers, etc.  It's a very odd little system.  I was doing
> a bit more reading last night and while the ALU is 12 bits wide, the Link
> (carry) bit is the carry out from bit 7.  Logical operations only operate
> on the low 8 bits, though there are variants that work on the upper 4 bits
> only, as well.
> - Josh

Maybe here:   ?

I think the "i" wasn't an "ell" it was an "I" as in "I think ..."?


Antonio Carlini
antonio at

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