weird find: papertape "patch" puncher

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Fri Mar 5 16:45:16 2004

>
> In message <!~!UENERkVCMDkAAQACAAAAAAAAAAAAAAAAABgAAAAAAAAAC6RJHIx+0kSwesJ7EUMCZcKAAAAQAAAA8k/XLfXfnU6YRMKg8i0vWwEAAAAA_at_optonline.net>
> "David V. Corbin" <dvcorbin_at_optonline.net> wrote:
>
> > Ps: does anyone have some of the adhesive papertape patches?
> Well, seeing as we're on the subject of papertape hardware, I'd love to get
> hold of a papertape punch, reader and a few rolls of papertape. I've been
> told nothing beats watching the papertape whizz by as a program is loaded
> into RAM. Personally, I think a papertape reader would make a nice addition
> to my 6502 single-board computer :). Small size and light weight would be
> useful, and operation from 240V AC (or low voltage DC) is essential.
> I suppose I could hack together a papertape reader, but I doubt a papertape
> punch would be particularly easy to homebrew :(

There have been several designs for homebrew readers, the schematic of
one is in the back of the S100 handbook. The unidentified chips in that
schemaitc are obviously 555 timers, used as schmitt triggers (!). The
only difficult thing to make is the photodiode array for the read head. I
wonder if you could use plastic fibre-optic cable to lead the light from
a row of holes to some normal-size photodetectors mounted on a PCB in a
convenient arrangement. It would be easier than finding some
photodetectors that you could mount on 0.1" centres.

Making a punch is a lot harder!

If you want my recomendations as to units to look out for (assuming you
have a choice).

Punches :

Facit 4070. Easily the top of the list. It's easy to keep going,
mechnicallly simple, and has a simple interface (close to Centronics,
normally). 'Only' 75 cps, though.

Teletype BRPE. OK, it's fast (110cps), but a pain to interface. Not hard
to keep running, though.

Other Data Dynamics units seem to often have interfaces close to the
BRPE, but are slower. Can be useable

The GNT34 isn't bad (and is tiny), but you really want to get one with
electronics (e.g. as part of the Trend Paper Tape Station).

Reders.

If given the choice, get a Trend HSR500 (500cps) or UDR350/UDR700. These
are quite small, have built-in electronics, and go on for ever. It's
almost impossible not to set one up correctly. I _love_ these units. UDRs
and HSR500Ps have a builit-in mains PSU, the HSR500 needs mains (for the
motor), +5V, and IIRC +24V. Not impossible to power. The other advantage
of these units is that they're entirely optical (even the sprocket track)
and have a capstan/pinsh roller tape feed. There are therefore very kind
to the tapes

Other, smaller, optical readers often have optical detection for the data
holes only, with a sprocket wheel driven by a stepper motor to feed the
tape. Typcially limited to 50cps maximum (most are 30cps), they're
useable, but not as kind to the tapes. Facit made a thing which looks
like a modified 4070 punch with such a reader built into the front cover
(and quite complex electronics inside). Useable, but...

Avoild totally mechnanical readers unless you like repairing tapes and
correcting read errors. The Teletype ASR33 is fun, but I wouldn't want to
use one seriously!

-tony
Received on Fri Mar 05 2004 - 16:45:16 GMT