Z4648252@SFAUSTIN.BITNET (Z4648252) (07/12/89)
Ok, everyone has me sufficiently frightened. Even though I have
been working my DeskJet for nearly a year (August 88) on my Mega2 ST,
I have yet to experience burned out ports. However, after the Closes
alerted everyone to a potential problem AND after all these other
reports.....it's official--I'm worried! I'm 200 miles from the closest
ST dealer and don't relish the idea of being without "Maggie".
Question. Will Diana or anyone else place a schematic for the
buffer that will correct everything? I'm convinced now that I had
better build this thing. I use my DeskJet DAILY and fear what *might*
happen! 'whimper'...
Larry Rymal in East Texas <Z4648252@SFAUSTIN.BITNET>hase@netmbx.UUCP (Hartmut Semken) (07/13/89)
In article <890711.19492732.085188@SFA.CP6> Z4648252@SFAUSTIN.BITNET (Z4648252) writes: > Question. Will Diana or anyone else place a schematic for the >buffer that will correct everything? I'm convinced now that I had >better build this thing. I use my DeskJet DAILY and fear what *might* >happen! 'whimper'... This one will do: ST Parallel 7407 D0 |\ --------------| >------ to Printer D0 |/ D1 |\ --------------| >------ to Printer D1 |/ D2 |\ --------------| >------ to Printer D2 |/ D3 |\ --------------| >------ to Printer D3 |/ D4 |\ --------------| >------ to Printer D4 |/ D5 |\ --------------| >------ to Printer D5 |/ D6 |\ --------------| >------ to Printer D6 |/ D7 |\ --------------| >------ to Printer D7 |/ STROBE |\ -------------| >------- to Printer STROBE |/ The layout of the parallel ports 25-pin SUB D connector is found in the ST "manual". The 7407 has 6 open collector drivers, so you need 2 of them (the pullup resistor are in the printer). the +5volts for the drivers you can get from the joystic port (useful with the ST 1040; not useful with the Megas :-) or from somewhere inside the ST, perhaps the power connector to the internal drive (use some plugeble T-adaptor: easy to install, easy to remove...). That does it for a Seikosha cp80 (really weird, old thing) and my Epson still works just fine. hase -- Hartmut Semken, Lupsteiner Weg 67, 1000 Berlin 37 hase@netmbx.UUCP If there is something more important than my Ego, I want it caught and shot. Now! (Zaphod Beeblebrox)