31 Jul
2005
31 Jul
'05
7:06 p.m.
Allison:
No success so far. I'm going to write a small test program
tomorrow to accept a character from the SSM and echo it back. I have the
two ports configured two different ways -- the first equivalent to a
Revision 1 SIO (active low) and the second equivalent to an 8251. It's
still a remote possibility that the board is bad, so I hope this will
flush it out.
I'm still hopeful that someone on the list has a working SSM
2p-2s that they could report on how it's configured and how the cable is
wired. This has bothered me all day, which usually means it's a hardware
problem.
Rich
-----Original Message-----
From: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] On Behalf Of Allison
Sent: Sunday, July 31, 2005 3:09 PM
To: cctalk at classiccmp.org
Subject: Re: Serial Configurations (was Devilish Altair Serial
ConfigurationProblem)
Subject: Serial Configurations (was Devilish Altair Serial
ConfigurationProblem)
From: "Richard A. Cini" <rcini at
optonline.net>
Date: Sun, 31 Jul 2005 12:35:05 -0400
To: "'General Discussion: On-Topic and Off-Topic Posts'"
<cctalk at classiccmp.org>
All:
The problems I'm having have to be related to status bits and
device
initialization. The board is an SSM 2p+2s which is
based on the TMS6011
(which has lots of equivalent UARTs such as the
COM2502, 2017, TR1402,
AY3-1015). The SSM board is very flexible -- I can change status bit
order and polarity to match almost any configuration need. Right now I
have it strapped to match the Altair Revision 1 SIO board (ports 0/1,
RxStat=bit0, TxStat=bit1, active high polarity). I've also tried TxStat
at bit7.
That should work.
Does someone have sample working code for initialization, input
and
output? I have a few datasheets but none of them give
sample code
sequences. I'm missing something here and I'd appreciate a push.
OH, one more detail.. Most of the MITS software when loaded inits
based on the front pannel sense switches (IN FFh). The configuration
sets the board in use and bits. T he setting are in the MITS software
manuals.
Allison