Epson HPIL interface
ard at p850ug1.demon.co.uk
Tue Nov 24 16:16:40 CST 2009
I am trying to find something to put my latest E-bay purchase in. Note I
am not saying that I am trying to find somewhere to put it, I have that
problem whne I uy a complete computer system. This is just one PCB about
5" * 4"
Let me start with some backgrounf information. Everybody rememebrs the
Epson dot-matrix printes of the 1980s, things like the MX80, FX80 and so
on. They had a standard Centronics interface on a 36 pin Blue Ribbon
What is less well knwon is that these printers have an 2*13 socket on the
main PCB. 25 pins are used ,the other is a locating hey. This conenctor
carries most of the Centronics signals, power lines, and a few others. It
was designed for optional inteface PCBs, there is a blanking plate in
the top case to allow access to a connector on such a PCB.
For example, Epson made a couple of different serial interface PCBs. One
was a bit-banger -- if a particular pin (P/S-) on the connector is pulled
lwo, then data line D8 becomes a bit-banged serial input and the other 7
data lines are used to set the serial interface parameters. The other was
a serail-parallel converter using a microcontroller with buffer memory.
It jhad a parallel inteface to the printer.
Now HP sold a couple of printers called the HP82905 and HP82906. These
were based on Epson models -- in fact they _were_ Epson printers with
different firmware to handle the HP command set. They were fitted with an
Epson HPIB interface card as standard. But there was also a fairly rare
HPIL interace card, made by HP. And that is what I have just bought.
It's a PCB 82905-60001. It contains 2 chips, a 1LB3 (HPIL interface) and
MK3870 (mask-programmed microcontorller) with the obvious support
components. Since it just uses the stnadarsd parallel interface to the
rwst of the printer, it should work in any Epson printer with that
connector, no matter what firmeare is present (at least for printing text).
After getting in on E-bay, but before it arrived, I remembered I had the
Epson HPIB card somewhere. I could even rememebr were. I dug it out, and
found it was missing a jackpost from the HPIB connector. 2 hours later, I
had one fitted. No, it didn't take me that amount of time to find one, I
just graed some brass ron and turned one. FWIW, the screw thread on the
connecto that it screws into is 4-40 UNC, an odd choice (USA HPIB
jackposts have a 6-32 thread on that end, and the Japanese normally use
metric threads, so I would have expected either 6-32 UNC or M3 here).
This board contains 16 TTL chips so should be triival to repair if it
Anyway, the problem is that I am short of Epson printers. I have one. I
thought it would be triivial to find such devices, but alas not.
1) Does anyobody know which Epson models have this internal connector and
which therefore could be used with the interfaces
2) Anyone know for sure what models the HP82905 and 82906 are based on?
3) Anyone in the London (England) area got any such printes that they
want to sell cheaply? I suspect shipping them would be rather expensive,
hense the 'London area' criterion. Obviously the HP models would be fine
too, as would IBM5152 grapghics printers (the TechRef shows the connector
I am talking about).
Thanks in advance
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