Path: utzoo!attcan!uunet!husc6!uwvax!rutgers!bellcore!texbell!bigtex!natinst!cs.utexas.edu!eholley
From: eholley@cs.utexas.edu (Ed Holley)
Newsgroups: comp.os.minix
Subject: rs232 stuff
Keywords: rs232, serial
Message-ID: <4089@cs.utexas.edu>
Date: 25 Nov 88 00:40:55 GMT
Organization: U. Texas CS Dept., Austin, Texas
Lines: 19

For anyone that is having trouble with the serial port driver:

My serial driver absolutely refused to do anything at all.  I eventually
found that this was due to the transmit/receive buffer not being
read after the modem was set up.  By adding the following line to
the bottom of procedure config_rs232 in rs232.c, I got my modem to work.

  port_in(base + RS232_TRANSMIT_HOLDING,&value);

where value is declared as as integer.

This clears out any interrupts the port thinks have occured, allowing
more interrupts to occur.  I hope this helps somebody else out there.

Incidently, after spending all the time to figure this out, I discovered
that this driver is not very usable, at least on my poor old slow PC
compatable.  But it does work.

	Ed Holley (eholley@cs.utexas.edu)