DEC LA36 Decwriter II

From: Truthan,Larry <truthanl_at_oclc.org>
Date: Thu Dec 26 15:39:00 2002

I have the engineering prints in the LA 36 Decwriter II

LA36 (MPC5) sheet 5 of 8 shows 20 ma RECIEVE on J3 pin 7(+) and Pin 3(-)
bridged by a 3.3 volt zener D4 746A feeding a 4N26 (E43) opto-isolator
which drives a MXAA05 (Q4) driver transitor which has its collector on J4
pin 2 "S.I." (serial in)

20 ma TRANSMIT is on J3 Pin 5(+) and Pin 2(-). These pins are bridged
by a 1N4004 diode D6. This diode also is parallel to the
emitter/collector of Q2, an A05. which is driven by another 4N26
opto-isolator (E47). S.O. is J4 pin 4. It is driven by a 7404 inverter
(E62)-(Input is 7404 pin 3 connected to the diode cathode of the
opto-isolator, output is 7404 pin 4, which connects directly to J4 pin 4,
"S.O." serial out)

Sincerely

Larry Truthan


In reply to:

Message: 29
Date: Thu, 26 Dec 2002 09:39:19 -0700
From: Kevin Handy <kth_at_srv.net>
To: cctalk_at_classiccmp.org
Subject: Re: DEC LA36
Received on Thu Dec 26 2002 - 15:39:00 GMT