len@qumix.UUCP (Leonard Labar) (11/04/84)
I've been attempting to connect a commodore vic-1525 dot matrix printer to my Macintosh with no success. Below is the connection scheme. I'm sure of my connector pinouts. Maybe someone can help me out on the handshaking timing required. The printer does NOTHING. MAC function PRINTER function --- -------- ------- -------- 1 ground ---------------------------- 2 ground 2 +5v n.c. 3 ground n.c. 4 TXD+ ------------------------------ 5 serial data 5 TXD- n.c. 6 +12v n.c. 7 printer handshake ----------------- 3 serial atn i/o 8 RXD+ n.c. 9 RXD- n.c. n.c. 1 serial srq in n.c. 4 serial clk i/o n.c. 6 reset/ It seems like what is required is an RS422 to IEE488 converter circuit. Does anyone know an economical, easy way to do this? Help!
henry@utzoo.UUCP (Henry Spencer) (11/05/84)
> It seems like what is required is an RS422 to IEE488 converter circuit. > Does anyone know an economical, easy way to do this? Help! I think you're just plain out of luck. RS422 is a point-to-point serial signalling technique, whereas IEEE488 is a parallel bus, with all the extra complexity that implies. There is no solution that just needs rewiring; a non-trivial amount of circuitry is going to be needed. There must be serial interfaces for IEEE488 available commercially, but I suspect you won't like the price tags. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
ken@turtlevax.UUCP (Ken Turkowski) (11/07/84)
> > It seems like what is required is an RS422 to IEE488 converter circuit. > > Does anyone know an economical, easy way to do this? Help! > > I think you're just plain out of luck. RS422 is a point-to-point serial > signalling technique, whereas IEEE488 is a parallel bus, with all the > extra complexity that implies. There is no solution that just needs > rewiring; a non-trivial amount of circuitry is going to be needed. IEEE-488 is informally known as a parallel RS-232. There is at least one manufacturer of a RS-232 to IEEE-488 converter (I do have literature around here somewhere). There are also IEEE-422 boards to plug into a UNIBUS, QBUS, MULTIBUS, ... --- UNIBUS, QBUS are trademarks of DEC, MULTIBUS is a trademark of Intel -- Ken Turkowski @ CADLINC, Palo Alto, CA UUCP: {amd,decwrl,flairvax,nsc}!turtlevax!ken ARPA: turtlevax!ken@DECWRL.ARPA
cem@intelca.UUCP (Chuck McManis) (11/09/84)
If I am not mistaken the IEEE-488, aka the GPIB bus is parallel, whereas
the RS-232 port is serial. The RS-232 488 bus refers to an IEEE-488
bus with RS-232 signal levels (ie <-3V ,>+3V) whereas the RS-422 levels
refer to a differential signal (2 wires/signal line the voltage difference
is >+/- 3 V) An RS-422 serial to IEEE-488 parallel converter would
probably involve a single chip microcomputer with a serial channel and
some parallel lines that was programmed to do the conversion. (an 8751
comes to mind :-) ) Then again I may have entirely misinterpreted the
question.
--
-- Chuck - - - D I S C L A I M E R - - -
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