Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!spdcc!m2c!frog!rms
From: rms@frog.UUCP (Bob Santy, Software)
Newsgroups: comp.sys.m6809
Subject: Re: homebrew coco serial port problems
Message-ID: <1568@frog.UUCP>
Date: Fri, 21-Aug-87 15:12:00 EDT
Article-I.D.: frog.1568
Posted: Fri Aug 21 15:12:00 1987
Date-Received: Sun, 23-Aug-87 11:35:47 EDT
References: <822@sask.UUCP>
Organization: Superfrog Heaven [ CRDS, Framingham MA ]
Lines: 20
Keywords: 6551
Summary: COCO III and ACIAs


I have also had "funny" behavior on the part of the ACIA chip in the RS232
pack.  Upon having a discussion with Kevin Darling (one of the CIS OS9 COCO
experts on CompuServe), I started experimenting with slowing the COCO III
down to 1 Mhz inside the ACIA driver with some success.  The experiment was
not completely successful because the interrupt handler slowed the system
down upon receipt of control.

The upshot of it is that some ACIA chips don't seem to like the E clock
running above 1 Mhz.  Slowing the clock down via a poke with the debugger
gives the most success, but there must be something else I'm not doing because
the behavior still exists but less frequent.  The loss of characters on
input which gets worse as the baud rate is increased is my main problem.

Of course, I could be way off base with this assement of the problem.

Comments appreciated.

Bob Santy
.