Hi Gray,

If you connect PIC direct to a ISA based modem, at least 8bit port(data)
should be used, more you also have to supply the address line, W/R, etc,
like controlling a intel8250, it's too complex, I think.

I guess the ISA modem also has a UART, if you can find it, can still use
a SCI port to driven it. I don't know if the ISA modem is supplied via
+12 or -12 from ISA bus, if so, your PIC power supply must output
those voltage.


Jerry

At 04:10 PM 6/25/98 -0400, you wrote:
>Hello Everyone,
>
>After reading the thread about using a 16c64 to dial a modem and link to a
>PC, I've thought of a variation to this question:
>
>Since PC-based modems are relatively cheap and plentiful these days, has
>anyone tried to take an off-the-shelf PC-based modem card (e.g. ISA based)
>and interface it directly to any PIC processor?  This might be an easy (and
>cheap) method of getting PIC-based modem communications going.  Of course,
>one could also use an external modem that communicates via an RS232 link,
>however, an ISA-based modem card soution is likely cheaper.  Any comments?
>
>Regards,
>Gary Pepper
>
>Ottawa, Ontario, Canada
>e-mail: gpepper@capitalnet.com
>
>