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From: dlb5404@tamuts.tamu.edu (Daryl Biberdorf)
Newsgroups: comp.sys.3b1,comp.sys.att
Subject: Need 3b1-end pinouts for parallel interface
Keywords: parallel pinout
Message-ID: <12347@helios.TAMU.EDU>
Date: 19 Feb 91 15:27:19 GMT
Sender: usenet@helios.TAMU.EDU
Followup-To: comp.sys.3b1
Distribution: na
Organization: Texas A&M University
Lines: 44

I was going to hook up the old C.Itoh Prowriter 8510 this weekend
when I noticed that my 3B1 uses a female centronics connector instead
of the more common DB-25 for its parallel port.  After calling around,
no local businesses stock the male centronics-male centronics cable I need
and special ordering it looks like it will cost more than I think it should.
:)  So I guess I'll make my own.

Anyway, I have the pinouts for the printer (equivalent to the Apple
Imagewriter I and the AT&T 470, I believe), but I don't have them
for the computer.  Can anyone help?

In case it matters, here are the pinouts for the Prowriter:

	Pin	Signal Name
	1	DATA STB'   (' indicates low true)
	2-8     data (2 is LSB, 8 is MSB)
	10	ACK'
	11	INPUT-BUSY
	12	PE
	13	SELECT
	14	0 V.
	15	not connected
	16	0 V.
	17	CHASSIS GND
	18	+5 V. DC
	19-30   TWISTED PAIR GND (for pins 1-11 and 31, in order.
		                  What are these for?  couldn't tell.)
	31	INPUT PRIME'
	32	FAULT'
	33	0 V.
	34	not connected
	35	not connected
	36	INPUT BUSY

These pin numbers are for the standard 36-pin Centronics-style connector.
Will I need a full 36-conductor cable to accomplish all these connections?
(33 if I ignore the NC pins)  If so, how does a clone accomplish
parallel communications with a DB-25 connector and still allow for
communications TO the machine through that connector?

Thanks in advance for any help you can provide. 

--Daryl Biberdorf,  dlb5404@{rigel,tamuts}.tamu.edu
  Texas A&M University