jade@hydra.unm.edu (Eric Jaderlund) (08/30/90)
My girlfriend recently bought a used CTS 21AHC 1200buad modem at a steal of a price and I'm trying to get it to work on her Mac 512K. I am having some problems that I hope someone can help with. First there was the struggle with the cable but I think I have made it correctly, I wired it as follows: Mac(9pin) Modem(25pin) --------- ----------- 1 to 1 3 to 7 5 to 2 7 to 5 9 to 3 Is this right? My problems are 3-fold 1) When I first turn it on the modem starts spitting characters to the computer non-stop. After playing for about 10 minutes it settles down and talks nicely to the computer (I am using Red Ryder, by the way). AT gives an 'OK' response and I can check and set all the registers. But if the modem is off for a while I have to go through the 10 minof garbage before it works. 2) If I try an analog loopback test (this should echo typed characters back to the screen) it goes into that mode and once again out comes the garbage characters non-stop unit I give the interrupt comman (+++) then it stops and goes back to normal. 3) The biggest problem is that it wont dial. An 'AT DT', or any other dial command, spits a line or two of garbage and then says 'NO DIALTONE'. The phone cables seem fine and the regular phone works OK when plugged into the modem. Also I can hear the little realy 'click' after the AT DT command and click again a few seconds later after it cant detect the dialtone. I would suspect a hardware problem but the person who we got it from used it on his IBM-XT without any trouble. Any ideas???? All help appreciated. Thanks, --------------------------------------------------------------------------- Eric Jaderlund jade@hydra.unm.edu Univ. of New Mexico