Re: NULL modem projects

[cheer@i.hate.spam (Christopher D. Heer)]

It was 7 Mar 1997 11:31:22 -0500.  I was reading instead of working.  And John 
Ruschmeyer <jruschme@hiway1.exit109.com> said:

>In article <1342551240-970307124700@rook.wa.com>,
>Brian Hammack <brian.hammack@rook.wa.com> wrote:

>> JE| 2) Is it possible to make a *serial port* out of a <Insert name of
>>   | old    300/1200/2400 baud modem> modem?

>>Trying to figure why the RS232 of the serial card isn't good enough...

>Maybe I should clarify. My assumption from all the "null modem" posts is
>that there are a lot of people whose Apples have internal modems as
>opposed to serial cards. Further, many of these are of the 300/1200 baud
>variety.

I was making the same assumption.  It'd be kind of a silly question otherwise.

>In my limited experience, it seemed that such a modem consisted of some
>bus logic, a UART, and some modem circuitry. I was positing the question
>of whether anyone had taken an obsolete internal modem and converted it
>into a serial port. The advantage being that one *should* be able to get
>a higher transfer rate than is possible through the modem hardware.

>There is some precedent for this. In the CoCo (Radio Shack Color Computer)
>world, it is a popular hack to take the old RS 300 Baud modem pack, cut
>off the half of the board with the modem circuit (leaving behind the 6551),
>jumpering two cut traces, and tacking on a small circuit containing a
>DB-25 and some line drivers (1488/1489, etc.).

>Any thoughts?

Yeah. . . that it sounds (a) doable, and (b) not worth the bloody effort, what 
with Super Serial cards costing around $15 these days.
-- 
          Christopher D. Heer - cheer at us dot oracle dot com
     My opinions are my own and do not reflect those of Oracle Corp.
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