17 Feb
2003
17 Feb
'03
4:26 p.m.
From: "Mike Davis"
<ipscone(a)msdsite.com>
Let me start off by saying "I hate RS-232". Anyway, now that that's
out of the way, I am having a problem with an RS-232 interface on an
IMSAI SIO board.
I've been debugging a North Star drive and I was having problems with
it booting (DOS 2) in my IMSAI. I would get the "*" prompt but OS
would not recognize my Soroc terminal input. At first I thought it
might be buggy code on my DOS floppy.
Anyway, to make a long story short, I have multiple of everything and
have ruled out everything but something to do with my RS-232
configuration (I guess). I have 2 SIO board and both behave the same
way.
I'm documenting what I have here, in case someone sees something
wrong that I've overlooked. BTW, this was previously working without
any different configuration or hardware, with the exception of the RS-
232 cable from the Soroc to the IMSAI. This is a brand new cable
that was working just a few weeks ago so I'm having a hard time
believing there is anything wrong with this cable. I have only one,
if you can believe that. I'm going to get another this weekend, if I
have not figured this problem out by then.
Anyway...
I'm using Port A (on the SIO) and have configured the A3 Jumper to
have
TD Pin 1 to Pin 15 RD
RD Pin 2 to Pin 16 TD
RTS Pin 4 to Pin 12 CTS
CTS Pin 5 to Pin 13 RTS
DTR Pin 7 to Pin 9 DSR
DSR Pin 8 to Pin 10 DTR
By the way, the SIO manual shows DTR-DSR as through straight throuh
in stead of crossover, as shown above. Seems that it should be
crossed over like the others. In any case, I have tried both ways
but it doesn't seem to make any difference.
I'm using a straight through DB-25 cable from my Soroc to my IMSAI.
I'm using the following CIN and COUT routines.
2900 DB03 CIN IN STAT
2902 E602 ANI IBIT
2904 CA0029 JZ CIN
2907 DB02 IN DATA
2909 E67F ANI 7FH
290B C9 RET
290C DB03 COUT IN STAT
290E E601 ANI OBIT
2910 CA0C29 JZ COUT
2913 78 MOV A,B
2914 D302 OUT DATA
2915 C9 RET
Areas I'm wondering about.
1) Is the A3 header correct for the IMSAI as the computer end and the
Soroc as the terminal. 3 pairs crossed over. It does write to the
Terminal properly and when I press the Break Key, I get an echo from
the IMSAI of *?, which seems normal.
I have tested the input routine, which is part of the DOS input
routines, and was working previously, by modifying it to display the
status to the programmed output on the IMSAI with this code.
0000 DB03 CIN IN STAT
0002 DBFF OUT FFH (programmed output port)
0004 E602 ANI IBIT
0006 CA0000 JZ CIN
0009 DB02 IN DATA
290B E67F ANI 7FH
290D C30000 JMP CIN
Hi
There may already be a status in the port, that maybe
why you see no change. You need to put a dummy read first.
This will cause the drop of alternate characters when
working right but this is for debug. Try:
CIN IN DATA
CIN1 IN STAT
OUT FFH
ANI IBIT
JZ CIN1
IN DATA
ANI 7FH
JMP CIN
If you don't see any change, try some of the other ports,
near by for STAT, like 0 , 1 or 2.
If that fails, you could be having a problem with the
serial lines someplace. You need to check the levels
on the serial chip inputs.
Dwight
Seems that this should show whatever is read in the status port for
Port A. But when executed, the status never changes after I tap any
key.
My system is behaving as if it just can't receive any data from the
terminal. It's driving me buggy as this is a relatively simple
problem. Like I said, I have multiple SIO and they all behave the
same. I even tried another terminal and get the same results. I
have also even tried different ribbon cable from the SIO to the RS-
232 connector.
Anyone see something bonehead that I overlooked?
Thanks,
17 Feb
17 Feb
4:41 p.m.
From: "Mike Davis"
<ipscone(a)msdsite.com>
Let me start off by saying "I hate RS-232". Anyway, now that that's
out of the way, I am having a problem with an RS-232 interface on an
IMSAI SIO board.
[...]
Anyone see something bonehead that I overlooked?
A breakout box? :-)
--
Copyright (C) 2002 R. D. Davis The difference between humans & other animals:
All Rights Reserved an unnatural belief that we're above Nature &
rdd(a)rddavis.org 410-744-4900 her other creatures, using dogma to justify such
http://www.rddavis.org beliefs and to justify much human cruelty.
6:35 p.m.
I tried the dummy code test but it made no difference. Also, the
status port address is fixed, once the board is addressed. If Port A
is 02h, then the status for port A is 03h.
The thing that may be confusing me is that this was a previously
working system, with this configuration. So, the configuration and
such should already be correct.
And the patches made to the DOS disk, match the settings on the board
(another good sign). And since I have multiple SIO boards that all
behave the same way, I ruled out a hardware failure. Of course, I do
have a cable that wasn't in the original system. But the cable is
new.
The SIO also uses an 8251 and that has some control setup capability
but I have never had to program any of that. Just a reset and use
board jumpers for setup.
Perhaps it's time to stop assuming it was previously working. :-)
I'm pretty sure this is some sort of handshake issue.
Very strange.
From:
"Mike Davis" <ipscone(a)msdsite.com>
Let me start off by saying "I hate RS-232". Anyway, now that that's
out of the way, I am having a problem with an RS-232 interface on an
IMSAI SIO board.
I've been debugging a North Star drive and I was having problems with
it booting (DOS 2) in my IMSAI. I would get the "*" prompt but OS
would not recognize my Soroc terminal input. At first I thought it
might be buggy code on my DOS floppy.
Anyway, to make a long story short, I have multiple of everything and
have ruled out everything but something to do with my RS-232
configuration (I guess). I have 2 SIO board and both behave the same
way.
I'm documenting what I have here, in case someone sees something
wrong that I've overlooked. BTW, this was previously working without
any different configuration or hardware, with the exception of the
RS- 232 cable from the Soroc to the IMSAI. This is a brand new cable
that was working just a few weeks ago so I'm having a hard time
believing there is anything wrong with this cable. I have only one,
if you can believe that. I'm going to get another this weekend, if I
have not figured this problem out by then.
Anyway...
I'm using Port A (on the SIO) and have configured the A3 Jumper to
have
TD Pin 1 to Pin 15 RD
RD Pin 2 to Pin 16 TD
RTS Pin 4 to Pin 12 CTS
CTS Pin 5 to Pin 13 RTS
DTR Pin 7 to Pin 9 DSR
DSR Pin 8 to Pin 10 DTR
By the way, the SIO manual shows DTR-DSR as through straight throuh
in stead of crossover, as shown above. Seems that it should be
crossed over like the others. In any case, I have tried both ways
but it doesn't seem to make any difference.
I'm using a straight through DB-25 cable from my Soroc to my IMSAI.
I'm using the following CIN and COUT routines.
2900 DB03 CIN IN STAT
2902 E602 ANI IBIT
2904 CA0029 JZ CIN
2907 DB02 IN DATA
2909 E67F ANI 7FH
290B C9 RET
290C DB03 COUT IN STAT
290E E601 ANI OBIT
2910 CA0C29 JZ COUT
2913 78 MOV A,B
2914 D302 OUT DATA
2915 C9 RET
Areas I'm wondering about.
1) Is the A3 header correct for the IMSAI as the computer end and the
Soroc as the terminal. 3 pairs crossed over. It does write to the
Terminal properly and when I press the Break Key, I get an echo from
the IMSAI of *?, which seems normal.
I have tested the input routine, which is part of the DOS input
routines, and was working previously, by modifying it to display the
status to the programmed output on the IMSAI with this code.
0000 DB03 CIN IN STAT
0002 DBFF OUT FFH (programmed output port)
0004 E602 ANI IBIT
0006 CA0000 JZ CIN
0009 DB02 IN DATA
290B E67F ANI 7FH
290D C30000 JMP CIN
Hi
There may already be a status in the port, that maybe
why you see no change. You need to put a dummy read first.
This will cause the drop of alternate characters when
working right but this is for debug. Try:
CIN IN DATA
CIN1 IN STAT
OUT FFH
ANI IBIT
JZ CIN1
IN DATA
ANI 7FH
JMP CIN
If you don't see any change, try some of the other ports,
near by for STAT, like 0 , 1 or 2.
If that fails, you could be having a problem with the
serial lines someplace. You need to check the levels
on the serial chip inputs.
Dwight
>
>Seems that this should show whatever is read in the status port for
>Port A. But when executed, the status never changes after I tap any
>key.
>
>My system is behaving as if it just can't receive any data from the
>terminal. It's driving me buggy as this is a relatively simple
>problem. Like I said, I have multiple SIO and they all behave the
>same. I even tried another terminal and get the same results. I
>have also even tried different ribbon cable from the SIO to the RS-
>232 connector.
>
>Anyone see something bonehead that I overlooked?
>
>Thanks,
6:54 p.m.
Tada! Man that was frustrating. But I found the problem. Turns out
that I had another board in the system that was conflicting with my
SIO.
I was reading the IMSAI manual for the SIO (which is far too short)
and after that there was a section on the MIO. I began to think that
maybe the MIO was used instead of the SIO. Nope! That wasn't the
problem. But just on a hunch, since I hadn't checked the addressing,
I removed the MIO board. Tada! It all began to work.
Evidently, the MIO was added later and never tested with the drive.
I'll leave that for the weekend but at least I have my North Star
drives booting and working properly now.
Whew! Thanks to those that tried to help.
Mike
From:
"Mike Davis" <ipscone(a)msdsite.com>
Let me start off by saying "I hate RS-232". Anyway, now that that's
out of the way, I am having a problem with an RS-232 interface on an
IMSAI SIO board.
I've been debugging a North Star drive and I was having problems with
it booting (DOS 2) in my IMSAI. I would get the "*" prompt but OS
would not recognize my Soroc terminal input. At first I thought it
might be buggy code on my DOS floppy.
Anyway, to make a long story short, I have multiple of everything and
have ruled out everything but something to do with my RS-232
configuration (I guess). I have 2 SIO board and both behave the same
way.
I'm documenting what I have here, in case someone sees something
wrong that I've overlooked. BTW, this was previously working without
any different configuration or hardware, with the exception of the
RS- 232 cable from the Soroc to the IMSAI. This is a brand new cable
that was working just a few weeks ago so I'm having a hard time
believing there is anything wrong with this cable. I have only one,
if you can believe that. I'm going to get another this weekend, if I
have not figured this problem out by then.
Anyway...
I'm using Port A (on the SIO) and have configured the A3 Jumper to
have
TD Pin 1 to Pin 15 RD
RD Pin 2 to Pin 16 TD
RTS Pin 4 to Pin 12 CTS
CTS Pin 5 to Pin 13 RTS
DTR Pin 7 to Pin 9 DSR
DSR Pin 8 to Pin 10 DTR
By the way, the SIO manual shows DTR-DSR as through straight throuh
in stead of crossover, as shown above. Seems that it should be
crossed over like the others. In any case, I have tried both ways
but it doesn't seem to make any difference.
I'm using a straight through DB-25 cable from my Soroc to my IMSAI.
I'm using the following CIN and COUT routines.
2900 DB03 CIN IN STAT
2902 E602 ANI IBIT
2904 CA0029 JZ CIN
2907 DB02 IN DATA
2909 E67F ANI 7FH
290B C9 RET
290C DB03 COUT IN STAT
290E E601 ANI OBIT
2910 CA0C29 JZ COUT
2913 78 MOV A,B
2914 D302 OUT DATA
2915 C9 RET
Areas I'm wondering about.
1) Is the A3 header correct for the IMSAI as the computer end and the
Soroc as the terminal. 3 pairs crossed over. It does write to the
Terminal properly and when I press the Break Key, I get an echo from
the IMSAI of *?, which seems normal.
I have tested the input routine, which is part of the DOS input
routines, and was working previously, by modifying it to display the
status to the programmed output on the IMSAI with this code.
0000 DB03 CIN IN STAT
0002 DBFF OUT FFH (programmed output port)
0004 E602 ANI IBIT
0006 CA0000 JZ CIN
0009 DB02 IN DATA
290B E67F ANI 7FH
290D C30000 JMP CIN
Hi
There may already be a status in the port, that maybe
why you see no change. You need to put a dummy read first.
This will cause the drop of alternate characters when
working right but this is for debug. Try:
CIN IN DATA
CIN1 IN STAT
OUT FFH
ANI IBIT
JZ CIN1
IN DATA
ANI 7FH
JMP CIN
If you don't see any change, try some of the other ports,
near by for STAT, like 0 , 1 or 2.
If that fails, you could be having a problem with the
serial lines someplace. You need to check the levels
on the serial chip inputs.
Dwight
>
>Seems that this should show whatever is read in the status port for
>Port A. But when executed, the status never changes after I tap any
>key.
>
>My system is behaving as if it just can't receive any data from the
>terminal. It's driving me buggy as this is a relatively simple
>problem. Like I said, I have multiple SIO and they all behave the
>same. I even tried another terminal and get the same results. I
>have also even tried different ribbon cable from the SIO to the RS-
>232 connector.
>
>Anyone see something bonehead that I overlooked?
>
>Thanks,
7904
days inactive
7904
days old
3 comments
3 participants
participants (3)
-
dwightk.elvey＠amd.com -
ipscone＠msdsite.com -
rdd＠rddavis.org