rivero@kovacs.UUCP (Michael Foster Rivero) (11/23/85)
------------------ Thought I would pass this along to Amiga users wishing to hook up a modem. First off, check your Amiga users guide for the pinouts on the rs-232 cable. There are a few non-standard pins that carry voltage. These can ruin your modem and the Amiga itself if you plug them in. CHECK THE AMIGA USERS GUIDE. Next, pin 20 on the connector is supposed to carry a data- terminal ready signal to tell the modem that you are on-line. This would normally be +5 volts, but on the Amiga, there is no such signal. In fact, the line tests out at -5 volts. If your modem requires the DTR signal, then you should check to see if it has a DTR bypass switch somewhere inside (mine did), and switch it on. Otherwise, the modem will ignore the Amiga. I am posting this as I did not find any referances to the DTR signal not being usable anywhere in the manuals. Michael Rivero
hamilton@uiucuxc.CSO.UIUC.EDU (12/01/85)
> Next, pin 20 on the connector is supposed to carry a data- > terminal ready signal to tell the modem that you are on-line. > This would normally be +5 volts, but on the Amiga, there is no > such signal. In fact, the line tests out at -5 volts. > I am posting this as I did not find any referances to the > DTR signal not being usable anywhere in the manuals. did you check that signal while actually using the serial port? the reasonable assumption is for it to be off (~-5v) until you open the serial device, and that's just what happens. if you leave your modem unstrapped (DTR counts), you get the "feature" of auto-hangup when you exit your modem program. wayne hamilton U of Il and US Army Corps of Engineers CERL UUCP: {ihnp4,pur-ee,convex}!uiucdcs!uiucuxc!hamilton ARPA: hamilton@uiucuxc.cso.uiuc.edu CSNET: hamilton%uiucuxc@uiuc.csnet USMail: Box 476, Urbana, IL 61801 Phone: (217)333-8703
stroyan@hpfcla.UUCP (12/03/85)
Pin 20 is supported. If you test it in the powerup state, you will find -5V, (Data Terminal NOT Ready.) If you then do an 'open "i",#1,"ser:"' from AbasiC, pin 20 goes to +5V, (NOW Data Terminal is Ready.) This is handy in some instances, since it will keep some modems from answering the phone when the Amiga isn't looking. :-) Mike Stroyan, hpfcla!stroyan P.S. Pardon the example in AbasiC, I'm holding out for Manx's Aztec C. (Come on January!)