Message-ID: <129@qumix.UUCP>
Date: Thu, 4-Oct-84 18:03:37 EDT
Article-I.D.: qumix.129
Posted: Thu Oct 4 18:03:37 1984
Date-Received: Fri, 5-Oct-84 20:46:19 EDT
Distribution: net
Organization: Qume Corp., San Jose, CA
Lines: 25
This is what I have on paper so far. Anyone tried something like this
yet?
-----RS422 (+5v line driver/receiver)-----
MAC function breadboard VICMODEM function
1,3 ground ground 1,12,A,N ground
2 +5v pwr to ic ------
4 TXD+ --> 3.3k pullup --> M data to modem
5 TXD- ---- ----
6 filtered +12v ---- 10 modem power
7 carrier detect<- LS04-8, 6 to 9, 5 to H,K carrier detect
8 RXD+ ---- ----
9 RXD- <-- LS04-4 &1k res., 3 to <- B,C data from modem
back of mac
-------------
\5 4 3 2 1 /
\9 8 7 6 /
--------
The Macintosh book (red cover) seems to say you can run the RS422 lines
open ended like this. They talk about doing it with the imagewriter.
I have yet to hook this up and try it. Also, I want to make sure the
"back of mac" shows the pinouts in the right place.