Path: utzoo!attcan!uunet!wuarchive!mit-eddie!bu.edu!orc!oliveb!tymix!tardis!jms
From: jms@tardis.Tymnet.COM (Joe Smith)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Converting parallel to serial port
Summary: Completely different chips and data rates
Message-ID: <1003@tardis.Tymnet.COM>
Date: 12 Apr 90 07:03:50 GMT
References: <7881@hydra.gatech.EDU>
Reply-To: jms@tardis.Tymnet.COM (Joe Smith)
Organization: BT Tymnet, San Jose, CA
Lines: 22

In article <7881@hydra.gatech.EDU> gt4662b@prism.gatech.EDU (BRANHAM,JOSEPH FRANKLIN) writes:
>In my quest to try and hook up an external terminal to my 1000, someone gave
>me a great idea. He claims that the parallel and serial ports on the
>1000 are driven by two identical chips. What I'd really like to do is this:
>	make a little board which plugs into where the chip which drives
>the parallel port which can make my parallel port act like a serial port.
>	1) Does anyone know how much off-base this idea is?

Your friend had incomplete information.  The serial port transmit and
receive data is handled by Paula, the custom chip that also handles
floppy-disk read and write, audio output, and analog joystick I/O.

The parallel port is driven by one of the 8250 chips.  The other 8250 chip
is identical, but is connected to the slowly-changing RS-232 signals;
DTR, RTS, CD, CTS, DSR, RI.

You would be better off buying a multi-port serial board.
-- 
Joe Smith (408)922-6220 | SMTP: jms@tardis.tymnet.com or jms@gemini.tymnet.com
BT Tymnet Tech Services | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms
PO Box 49019, MS-C41    | BIX: smithjoe | 12 PDP-10s still running! "POPJ P,"
San Jose, CA 95161-9019 | humorous dislaimer: "My Amiga speaks for me."