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,
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Eric Jaderlund
jade@hydra.unm.edu
Univ. of New Mexico