IBM 029 Card Punch and ASCII Machines

jwsmobile jws at
Tue May 12 11:20:04 CDT 2015

On 5/12/2015 9:01 AM, Dave G4UGM wrote:
>> -----Original Message-----
>> From: cctalk [mailto:cctalk-bounces at] On Behalf Of Paul
>> Koning
>> Sent: 12 May 2015 16:21
>> To: General Discussion: On-Topic and Off-Topic Posts
>> Subject: Re: IBM 029 Card Punch and ASCII Machines
>>> On May 11, 2015, at 11:56 PM, Eric Smith <spacewar at> wrote:
>>> On Sun, May 10, 2015 at 1:06 PM, Johnny Billquist <bqt at>
>> wrote:
>>>> I don't know how common card readers were, but I don't think any DEC
>>>> machines could punch cards.
>>> Almost all DEC machines up through early VAX supported card punch
>>> options. They just weren't very common other than on PDP-10.
>>> PDP-8: CP08
>>> PDP-10: CP10 (multiple variants) and CP20
>>> PDP-11 and VAX: CP11
>> Do you have any descriptions of that?  I have not seen any mention of a
> CP11
>> in any peripherals handbook, nor in any OS.  Was that a CSS product?  Who
>> built the punch engine?  What sort of interface did it use?
>> 	paul
> This site lists it as an M7824 card...
> this page from Chilton Labs
> implies a punch is available, but neither say which model punch...
> Dave
Microdata offered a custom wiring job to punch cards with a Univac 
keypunch, instead of IBM.

It used a standard board they had with a clocked parallel output to 
punch cards.  Carriage control would feed cards w/o the need to send all 
columns to trigger card feed.

There was a remote switch on the Univac Keypunch keyboard that allowed 
the unit to be switched to punch via the 1600.  Output could be done 
with the same machine code as a printer driver.

Interface was ascii, and logic in the keypunch custom board 
(wirewrapped) translated the codes.


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