26 Jun
2006
26 Jun
'06
8:04 p.m.
---ard at p850ug1.demon.co.uk (Tony Duell) says:
For the punch, I'd recommend a Facit 4070.
They're relatively common I
think, easy to maintain, and fairly simple. The basic interface is an 8
bit parallel one which can be linked to a PC with a little logic, there
was also an internal RS232/current loop card [1] and I believe I read
about an IEEE-488 card, but I've never seen one.
I got one of the Facit punches off of Ebay. It works quite well. I built up
an interface "adapter" that fits in a wire jumper box that has a couple of
DB-25's (make & female). The circuit needed a single 7400 NAND gate, and a
couple of zener diodes, but now my printer port drives the punch with NO
software modifications. The interface wasn't that complicated, and I had
to mush the parts together inside the adapter box, but it is just fine. I
connected it up to my Linux box and 'cat /dev/lp' does the trick.
Be aware: The Facit 4070 comes in two versions the 'DTL' version and the
'TTL'
version. The signal levels are a bit different. The TTL version is the later
one, and has easier level signals. Mine was the DTL one and needs some
clamping zener diodes to make it all work.
If you do get one with a serial option, note that it will probably cost a
bit more (I've seen $100). Without is much cheaper. The schematics are
on bitsavers. You might want to print them out on large (11x17 inch)
paper they look nicer that way.
As for the reader, that is another story. I got some off of eBay as well, but
I have yet to get them all interfaced up. The PeeCee really has no general
input port (with controls and the like).
--
Tom Watson
tsw at johana.com
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