building my own relay computer

[Dave G4UGM]

http://www.vintage-computer.com/vcforum/showthread.php?45888-FS-Documation-M
1000-Card-Readers

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of ben
> Sent: 14 February 2015 08:27
> To: cctalk at classiccmp.org
> Subject: Re: building my own relay computer
> 
> On 2/14/2015 1:14 AM, ben wrote:
> > On 2/14/2015 1:05 AM, Dave G4UGM wrote:
> >>
> >>
> >>> -----Original Message-----
> >>> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Dale
> H.
> >>> Cook
> >>> Sent: 14 February 2015 03:41
> >>> To: cctalk at classiccmp.org
> >>> Subject: Re: building my own relay computer
> >>>
> >>> At 08:14 PM 2/13/2015, Ben wrote:
> >>>
> >>> The alu has never relay been a problem with relays, but what about
> >>> main storage? Punched tape (paper/film/card) is no longer with us for
> I/O.
> >>>
> >>
> >> Punched tape is about. Check out the "green keys" list, 5-level stuff
> >> comes up from time to time, generally at low cost. There is some
> >> ex-CNC items on E-Bay at present but for silly prices. Whilst I
> >> haven't seen any on E-Bay there were three Documation readers
> >> advertised on the Vintage Computer forums.
> >>
> >>
> >>> Fifty years ago I got around that by building my own card reader
> >>> (very
> >> slow)
> >>> for input and hand-punching Hollerith cards with a hole punch. That
> >>> was some years before I got access to an IBM card punch in high
school.
> >>> Output
> >>> was a set of electro-mechanical counters, and they were a real pain
> >>> to implement.
> >>>
> >>
> >> Many folks have implemented photo electric tape readers, but these
> >> tend to be clocked off the small feed holes. I guess it wouldn't be
> >> too hard to build a photo electric reader that has a 3-d printed feed
> >> wheel that was driven by a stepper motor. In fact I am pretty sure
> >> you could even use a coil and ratchet arrangement, like this one
> >> here:-
> >>
> >> http://grabcad.com/library/cam-operated-ratchet-pawl-1
> >>
> >> but operated buy a coil and magnet rather than a rotating cam. Some
> >> one has actually made a complete but operated mechanical punch card
> >> computer..
> >>
> >> http://observationdeck.io9.com/a-3-d-printed-hand-cranked-punch-
> card-
> >> compute
> >>
> >> r-1481921919
> >>
> >> so I don't think its hard. Getting things 3-D printed isn't hard, in
> >> fact most FabLabs will have one and things can be printed for the
> >> cost of materials. Also Hack Space...
> >>
> >>   I think it's the punch that's harder. You would need to harden the
> >> punch pins, and the would need to have a very exact fit. I guess a
> >> CNC router could be used to make these...
> >>
> >
> > I think that needs real machine work. Strange what you could do 100
> > years ago you can not do today.
> > Computer controlled stuff is good for may things but not that.
> error: many things
> > Ben.
> >
> >
> >
> >