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!linus!decvax!decwrl!amd!qumix!len From: len@qumix.UUCP (Leonard Labar) Newsgroups: net.micro.cbm,fa.info-mac,net.micro,net.micro.apple Subject: Vic to Mac Null modem cable. Message-ID: <148@qumix.UUCP> Date: Mon, 29-Oct-84 00:38:33 EST Article-I.D.: qumix.148 Posted: Mon Oct 29 00:38:33 1984 Date-Received: Sat, 3-Nov-84 03:53:19 EST Distribution: net Organization: Qume Corp., San Jose, CA Lines: 53 Subject: Commodore to Mac Null modem cable I recently posted the interface below to the net. It works. Since then I've added a second cable that after unplugging the modem allows one to interface direct from the Commodore to the Mac. Its' description is listed below the first. -----RS422 (+5 volts line driver/receiver)------ MAC function breadboard VICMODEM function (conn. 1) 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 / -------- conn. 1 signal conn. 2 (to CBM) 1,A GND 1,A M TXD --> C (RXD) C <-- RXD M (TXD) H to GND carrier detect H to GND So now I can type on the CBM keyboard and everything appears on the Mac screen that I type. Big deal! Only problem is it doesn't work the other direction. I'm sure I don't have any faulty connections. Q. Anybody know the answer to the above problem? Q2. Is there a way for the Mac to receive and store M-Basic files via the modem port? I have a lot of files without peeks and pokes that I could use if I can do this.