1 Aug
2005
1 Aug
'05
1:24 p.m.
Dwight:
The software loopback is tonight's project. I have the terminal
software set for no flow control which should be OK for low baud and
loopback testing.
Actually, both the 8251 ACIA and the TMS6011 UAR/T have a reset
sequence requiring software initialization (with the 8251 being more arcane
than the 6011). With the Bit Streamer board, the baud rate is set by
switches but the other line parameters are set in software. With the SSM
board, the baud rate is set by a DIP jumper and the line parameters through
software.
More to come tomorrow...
Rich
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Dwight K. Elvey
Sent: Monday, August 01, 2005 1:10 PM
To: cctalk at classiccmp.org
Subject: RE: Serial Configurations (was Devilish Altair
SerialConfigurationProblem)
Hi Richard
There is no software initialization for these serial
chips unless the board has registers to do this. It is
usually done with jumpers. I'm not familiar with the SSM
boards but unless they got fancy, it should just be jumpers.
Check the data sheet for the chip, any of the ones list
should be the same.
Can you first connect things as RS232 with a light box?
You should then be able to make a simple loop back. At
lower baud rates, you should be able to watch the lights
flicker. A simple echo program should work here.
Once there, you should be able to scan the loader program
for the I/O operation and the status test used. Then
configure your board to use that status bit.
Dwight
From: "Richard A. Cini" <rcini at
optonline.net>
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