IBM 029 Card Punch and ASCII Machines

Dave G4UGM dave.g4ugm at
Tue May 12 16:48:08 CDT 2015

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at] On Behalf Of Eric Smith
> Sent: 12 May 2015 19:32
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: IBM 029 Card Punch and ASCII Machines
> On Tue, May 12, 2015 at 9:20 AM, Paul Koning <paulkoning at>
> wrote:
> >> On May 11, 2015, at 11:56 PM, Eric Smith <spacewar at> wrote:
> >> 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?
> The CP11 might have been CSS. I wouldn't have thought so since the one
> VAX site I knew that had one wouldn't likely have ordered CSS gear.
> Possibly at one time they had enough need for punching cards to justify
> buying CSS, but by the time I encountered it the punch was always powered
> down with a dust cover over it.
> >  Who built the punch engine?  What sort of interface did it use?
> AFAIK, DEC didn't build any card punches; they are all OEM'd with DEC-built
> interfaces. For the PDP-10 they OEM'd several different models, possibly
> from multiple vendors. I don't know the details of any of them, even though
> I used two different ones back in the day.
> IIRC, the CP20 was a Unibus device, and might or might not have been
> program-compatible with the CP11.

For the PDP-8 the docs I found on the web suggest a very old IBM punch from the 1950's


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