Re: Apple IIe + Modem (Sportster 14.4) ?

[david@uow.edu.au (David Wilson)]

kellihanb@aol.comDelete (KellihanB) writes:
>  Using  Apple Access II, I wasn't able to get it to automatically dial
>anything.  It says the modem isn't responding.  However, by going into terminal
>mode, and typing AT commands blindly, the modem will respond correctly and even
>make a connection.  Unfortunately this program has no facility for VT100 or
>ANSI emulation and can't even do XModem transfers...
>  So I got myself a copy of ZLINK.  The disk boots and I start ZLink.  It hangs
>after you select ZLINK.SYSTEM from the ProDOS start up.  Now, on a hunch, I
>tried unplugging the modem.  ZLINK works fine.  Plugging the modem in doesn't
>affect ZLINK until you type a key.  It locks up.  Unplugging the modem will get
>ZLINK going again...  
>   What's wrong?  Does anyone know what's causing this behavior?

Let me guess, your modem does not assert DCD until it connects to a modem
at the other end? A quick look at a 6551 data sheet shows:

As long as /DCD is high, no further interrupts for receiver will occur

See if you can program your modem to keep DCD active except when carrier
is lost it should pulse it and then return it to the active state.
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia