Vicmodem to Mac conversion.

[Info-Mac]

Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site qumix.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!cbosgd!ihnp4!zehntel!dual!amd!qumix!len
From: [email protected] (Leonard Labar)
Newsgroups: net.micro,net.micro.cbm,net.micro.apple,fa.info-mac
Subject: Vicmodem to Mac conversion.
Message-ID:
Date: Fri, 26-Oct-84 04:23:18 EST
Article-I.D.: qumix.140
Posted: Fri Oct 26 04:23:18 1984
Date-Received: Sun, 28-Oct-84 04:41:10 EST
Distribution: net
Organization: Qume Corp., San Jose, CA
Lines: 44



Subject: vicmodem to rs422 conversion


I just got this working!!! It only cost me $1.60 for the 9 pin
connector since I already had the $59 vicmodem and scrap parts.
Some will scoff but this is a poor man's modem for the Macintosh. A
bit slow (300 bps) but when the wife watches the budget you have to
start somewhere. I also have a home-brew auto dial circuit but I
haven't converted that from the vic to mac yet.


-----RS422 (+5 volts line driver/receiver)------


MAC function breadboard VICMODEM function

1 ground ground 1, A 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<- LS04-6 5 to <- H carrier detect

8 RXD+ ---- -----

9 RXD- <-- LS04-4 &1k res., 3 to <-- C data from modem



back of mac
-------------
\ 5 4 3 2 1 /
\ 9 8 7 6 /
--------

The MAC book (red cover) seems to say you can run the rs422 lines open
ended like this. They talk about doing it with the imagewriter.