14 Feb
2015
14 Feb
'15
12:55 a.m.
http://www.vintage-computer.com/vcforum/showthread.php?45888-FS-Documation-M
1000-Card-Readers
error: many things
> Ben.
>
>
>
>
-----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:
school.
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
>>
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.