6 Aug
2016
6 Aug
'16
7:59 a.m.
I've definitely got an MP-B.
What I'm thinking is I'll use one of the socketed 16k boards and go through the
RAMs to make sure I have good. ?But I'm having trouble understanding how to set the
jumpers to get the addressing to A000. ?I thought I had that by the guide for the ram on
the swtpc site (it's a Digital Research board). ?The machine only gets animated when
that weird piggybacked mpm board is plugged in.
I suppose if there are bad RAMs on the DR board that'd do it though.
Brad
Sent from my Samsung device
-------- Original message --------
From: Chris Elmquist <chrise at pobox.com>
Date: 2016-08-06 7:10 AM (GMT-08:00)
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
Subject: Re: SWTPC 6800
Simplifying the machine configuration can help too.? You should only need
MP-A (CPU), MP-S (serial interface) and MP-M at $A000 if you have the
SWTBUG ROM.? It only needs 128 bytes of RAM at $A000 so an unexpanded
(4K) or partially populated MP-M would be sufficient.
If you have MIKBUG, then you need MP-C instead of MP-S since MIKBUG does
not know how to talk to MP-S.
Removing all the other cards temporarily could eliminate conflicts due to
addressing, failed components, etc.
With this minimal configuration, you should be able to get SWTBUG's "$"
prompt.? MIKBUG will prompt with "*".
Also, check which backplane board you have.? Depending on vintage, you
may have MP-B or MP-B2.? MP-B2 allowed the I/O block address (normally
at $8000) to be changed.? If you have MP-B2 and someone has customized
the machine, then there will be more to figure out regarding where the
I/O is really located, what the monitor ROMs expect, etc.
http://www.swtpc.com/mholley/MP_B/MP_B_Index.htm
http://www.swtpc.com/mholley/MP_B2/MP_B2_index.htm
Chris
On Friday (08/05/2016 at 10:47PM -0700), Brent Hilpert wrote:
Do you have some RAM at $A000+ yet?
That's all that should matter as far as required RAM goes.
Presuming this is the holley page you were referring to:
http://www.swtpc.com/mholley/HiTerm/Test6800_Index.html
he does mention RAM needed at A000 for the BUGs, as Chris and I have been saying.
Without RAM there there's no stack for return addresses for subroutines executed in
the BUGs, so execution could head off to wherever.
On 2016-Aug-05, at 10:23 PM, Brad H wrote:
> Okay so.. I decided to try the MP-C board out, just for kicks.? No change.
> Then I decided to add one of the RAM boards.. the next one up in addresses.? Got a
little bit when I powered on.? Added one of the old MPM boards.. one that has memory chips
all piggybacked on one another.? Now when I powered up, the system was sending four or
five characters at a time, linefeed, four or five characters at a time, linefeed ad
infinitum.? I added the final MPM board.. zero.
> So.. I think we do have some ram problems.. most likely.? I'm thinking it would
be easiest to concentrate efforts on the socketed RAM boards.. test all the RAM out.?
I'm going to read up on addressing and try to understand a bit better what is going
on.? I'm thinking maybe I need to reconfigure the addressing on one of the boards to
match whatever that overstuffed MPM board is set to.
> Until I get an oscilloscope.. fooling around is about all I can do here.
>
> Sent from my Samsung device
>
> -------- Original message --------
> From: Chuck Guzis <cclist at sydex.com>
> Date: 2016-08-05? 3:55 PM? (GMT-08:00)
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
> Subject: Re: SWTPC 6800
>
> On 08/05/2016 02:15 PM, Brad H wrote:
>> I think I will have to figure out how to do that.? Additionally I
>> have one of those PC based oscilloscopes on the way.? I don't know
>> how to use them 100% but I'm about to learn I guess. :)
>>
>> I have one more question for you guys -- I have a few CT-1024
>> terminals and would really like this system to work with one of
>> those.? However, all of the CTs are quite delicate and are set I
>> think for 7, E, 2 @ 110 baud via soldered jumpers.? I'm a bit
>> reluctant to try pulling them apart to get in there and fix that.? Is
>> there a way to change the parity, etc settings on the SWTPC to match
>> the terminal?? Is it necessary?
>
> Well, 110 bps is a bit on the slow side--great for teletypes, not so
> much for video terminals.?? But you'll have to change the hardwired
> jumpers--the UART used in the CT1024 is not software-programmable.
>
> If this were my unit, I"d probably solder some pins into the pad holes
> and then either use slide on jumpers or wirewrap to set the
> characteristics.? That way, when changing things around, you won't be
> stressing the PCB.
>
> Something like this:
>
>
http://www.ebay.com/itm/10PCS-20CFemale-to-Female-1-Pin-Plug-Jumper-Cable-W…
>
> Search on "female jumper wires"
--
Chris Elmquist
6 Aug
6 Aug
8:24 a.m.
If you use a 16K board you'll want to config it to start at $8000, so that it covers
$8000-$BFFF.
If it goes higher than that it may end up in conflict with the ROMS and IO.
Alternatively, you could start with a minimal machine by reenabling the 6810 RAM on the
CPU board and all you would need plugged into the backplane is the CPU board and console
device board.
On 2016-Aug-06, at 7:59 AM, Brad H wrote:
I've definitely got an MP-B.
What I'm thinking is I'll use one of the socketed 16k boards and go through the
RAMs to make sure I have good. But I'm having trouble understanding how to set the
jumpers to get the addressing to A000. I thought I had that by the guide for the ram on
the swtpc site (it's a Digital Research board). The machine only gets animated when
that weird piggybacked mpm board is plugged in.
I suppose if there are bad RAMs on the DR board that'd do it though.
Brad
Sent from my Samsung device
-------- Original message --------
From: Chris Elmquist <chrise at pobox.com>
Date: 2016-08-06 7:10 AM (GMT-08:00)
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
Subject: Re: SWTPC 6800
Simplifying the machine configuration can help too. You should only need
MP-A (CPU), MP-S (serial interface) and MP-M at $A000 if you have the
SWTBUG ROM. It only needs 128 bytes of RAM at $A000 so an unexpanded
(4K) or partially populated MP-M would be sufficient.
If you have MIKBUG, then you need MP-C instead of MP-S since MIKBUG does
not know how to talk to MP-S.
Removing all the other cards temporarily could eliminate conflicts due to
addressing, failed components, etc.
With this minimal configuration, you should be able to get SWTBUG's "$"
prompt. MIKBUG will prompt with "*".
Also, check which backplane board you have. Depending on vintage, you
may have MP-B or MP-B2. MP-B2 allowed the I/O block address (normally
at $8000) to be changed. If you have MP-B2 and someone has customized
the machine, then there will be more to figure out regarding where the
I/O is really located, what the monitor ROMs expect, etc.
http://www.swtpc.com/mholley/MP_B/MP_B_Index.htm
http://www.swtpc.com/mholley/MP_B2/MP_B2_index.htm
Chris
On Friday (08/05/2016 at 10:47PM -0700), Brent Hilpert wrote:
Do you have some RAM at $A000+ yet?
That's all that should matter as far as required RAM goes.
Presuming this is the holley page you were referring to:
http://www.swtpc.com/mholley/HiTerm/Test6800_Index.html
he does mention RAM needed at A000 for the BUGs, as Chris and I have been saying.
Without RAM there there's no stack for return addresses for subroutines executed in
the BUGs, so execution could head off to wherever.
On 2016-Aug-05, at 10:23 PM, Brad H wrote:
> Okay so.. I decided to try the MP-C board out, just for kicks. No change.
> Then I decided to add one of the RAM boards.. the next one up in addresses. Got a
little bit when I powered on. Added one of the old MPM boards.. one that has memory chips
all piggybacked on one another. Now when I powered up, the system was sending four or
five characters at a time, linefeed, four or five characters at a time, linefeed ad
infinitum. I added the final MPM board.. zero.
> So.. I think we do have some ram problems.. most likely. I'm thinking it would
be easiest to concentrate efforts on the socketed RAM boards.. test all the RAM out.
I'm going to read up on addressing and try to understand a bit better what is going
on. I'm thinking maybe I need to reconfigure the addressing on one of the boards to
match whatever that overstuffed MPM board is set to.
> Until I get an oscilloscope.. fooling around is about all I can do here.
>
> Sent from my Samsung device
>
> -------- Original message --------
> From: Chuck Guzis <cclist at sydex.com>
> Date: 2016-08-05 3:55 PM (GMT-08:00)
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
> Subject: Re: SWTPC 6800
>
> On 08/05/2016 02:15 PM, Brad H wrote:
>> I think I will have to figure out how to do that. Additionally I
>> have one of those PC based oscilloscopes on the way. I don't know
>> how to use them 100% but I'm about to learn I guess. :)
>>
>> I have one more question for you guys -- I have a few CT-1024
>> terminals and would really like this system to work with one of
>> those. However, all of the CTs are quite delicate and are set I
>> think for 7, E, 2 @ 110 baud via soldered jumpers. I'm a bit
>> reluctant to try pulling them apart to get in there and fix that. Is
>> there a way to change the parity, etc settings on the SWTPC to match
>> the terminal? Is it necessary?
>
> Well, 110 bps is a bit on the slow side--great for teletypes, not so
> much for video terminals. But you'll have to change the hardwired
> jumpers--the UART used in the CT1024 is not software-programmable.
>
> If this were my unit, I"d probably solder some pins into the pad holes
> and then either use slide on jumpers or wirewrap to set the
> characteristics. That way, when changing things around, you won't be
> stressing the PCB.
>
> Something like this:
>
>
http://www.ebay.com/itm/10PCS-20CFemale-to-Female-1-Pin-Plug-Jumper-Cable-W…
>
> Search on "female jumper wires"
--
Chris Elmquist
12:53 p.m.
Okay... I'm beginning to think RAM config is a part of the problem here.
Here's how the boards are configured:
DRC 16k Bd 1 - Jumpered for 0000-3FFF
DRC 16k Bd 2 - Jumpered for 4000-7FFF
MP-M Bd 1 - Jumpers are - I can't figure it out. Supposed to be A to one of
the pads marked 0 - 7.. instead A goes to a 7401, which is piggybacked on
another chip. Pads 3 and 4 are also jumpered to this chip?
MP-M Bd 2- Jumpered from A - 5
Is it possible I have nothing for $A000 here?
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Brent
Hilpert
Sent: Saturday, August 6, 2016 8:24 AM
To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
Subject: Re: SWTPC 6800
If you use a 16K board you'll want to config it to start at $8000, so that
it covers $8000-$BFFF.
If it goes higher than that it may end up in conflict with the ROMS and IO.
Alternatively, you could start with a minimal machine by reenabling the 6810
RAM on the CPU board and all you would need plugged into the backplane is
the CPU board and console device board.
On 2016-Aug-06, at 7:59 AM, Brad H wrote:
I've definitely got an MP-B.
What I'm thinking is I'll use one of the socketed 16k boards and go
through
the RAMs to make sure I have good. But I'm having trouble
understanding how to set the jumpers to get the addressing to A000. I
thought I had that by the guide for the ram on the swtpc site (it's a
Digital Research board). The machine only gets animated when that weird
piggybacked mpm board is plugged in.
I suppose if there are bad RAMs on the DR board
that'd do it though.
Brad
Sent from my Samsung device
-------- Original message --------
From: Chris Elmquist <chrise at pobox.com>
Date: 2016-08-06 7:10 AM (GMT-08:00)
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: Re: SWTPC 6800
Simplifying the machine configuration can help too. You should only
need MP-A (CPU), MP-S (serial interface) and MP-M at $A000 if you have
the SWTBUG ROM. It only needs 128 bytes of RAM at $A000 so an
unexpanded
(4K) or partially populated MP-M would be sufficient.
If you have MIKBUG, then you need MP-C instead of MP-S since MIKBUG
does not know how to talk to MP-S.
Removing all the other cards temporarily could eliminate conflicts due
to addressing, failed components, etc.
With this minimal configuration, you should be able to get SWTBUG's "$"
prompt. MIKBUG will prompt with "*".
Also, check which backplane board you have. Depending on vintage, you
may have MP-B or MP-B2. MP-B2 allowed the I/O block address (normally
at $8000) to be changed. If you have MP-B2 and someone has customized
the machine, then there will be more to figure out regarding where the
I/O is really located, what the monitor ROMs expect, etc.
http://www.swtpc.com/mholley/MP_B/MP_B_Index.htm
http://www.swtpc.com/mholley/MP_B2/MP_B2_index.htm
Chris
On Friday (08/05/2016 at 10:47PM -0700), Brent Hilpert wrote:
> Do you have some RAM at $A000+ yet?
> That's all that should matter as far as required RAM goes.
>
> Presuming this is the holley page you were referring to:
> http://www.swtpc.com/mholley/HiTerm/Test6800_Index.html
> he does mention RAM needed at A000 for the BUGs, as Chris and I have been
saying.
>
> Without RAM there there's no stack for return addresses for subroutines
executed in the BUGs, so execution could head off to wherever.
>
>
> On 2016-Aug-05, at 10:23 PM, Brad H wrote:
>> Okay so.. I decided to try the MP-C board out, just for kicks. No
change.
>> Then I decided to add one of the RAM boards..
the next one up in
addresses. Got a little bit when I powered on. Added one of the
old MPM
boards.. one that has memory chips all piggybacked on one another. Now when
I powered up, the system was sending four or five characters at a time,
linefeed, four or five characters at a time, linefeed ad infinitum. I added
the final MPM board.. zero.
>> So.. I think we do have some ram problems..
most likely. I'm thinking
it would be easiest to concentrate efforts on the
socketed RAM boards.. test
all the RAM out. I'm going to read up on addressing and try to understand a
bit better what is going on. I'm thinking maybe I need to reconfigure the
addressing on one of the boards to match whatever that overstuffed MPM board
is set to.
> Until I
get an oscilloscope.. fooling around is about all I can do here.
>
> Sent from my Samsung device
>
> -------- Original message --------
> From: Chuck Guzis <cclist at sydex.com>
> Date: 2016-08-05 3:55 PM (GMT-08:00)
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk at classiccmp.org>
> Subject: Re: SWTPC 6800
>
> On 08/05/2016 02:15 PM, Brad H wrote:
>> I think I will have to figure out how to do that. Additionally I
>> have one of those PC based oscilloscopes on the way. I don't know
>> how to use them 100% but I'm about to learn I guess. :)
>>
>> I have one more question for you guys -- I have a few CT-1024
>> terminals and would really like this system to work with one of
>> those. However, all of the CTs are quite delicate and are set I
>> think for 7, E, 2 @ 110 baud via soldered jumpers. I'm a bit
>> reluctant to try pulling them apart to get in there and fix that.
>> Is there a way to change the parity, etc settings on the SWTPC to
>> match the terminal? Is it necessary?
>
> Well, 110 bps is a bit on the slow side--great for teletypes, not so
> much for video terminals. But you'll have to change the hardwired
> jumpers--the UART used in the CT1024 is not software-programmable.
>
> If this were my unit, I"d probably solder some pins into the pad
> holes and then either use slide on jumpers or wirewrap to set the
> characteristics. That way, when changing things around, you won't
> be stressing the PCB.
>
> Something like this:
>
> http://www.ebay.com/itm/10PCS-20CFemale-to-Female-1-Pin-Plug-Jumper-
> Cable-Wires-Multicolor-K-/262158878688?hash=item3d09e307e0:g:B-MAAOS
> wwE5WVLR6
>
> Search on "female jumper wires"
--
Chris Elmquist
1:44 p.m.
Gahh! So close!
https://drive.google.com/folderview?id=0B4pq0-BHd2x6WVFiZHdyMHBlNW8&usp…
ing
The prompt is totally what should be appearing, at least initially. But it
just keeps repeating itself over and over again and doesn't stop.
Notes: I tried jumpering the DRC board to A000 properly this time, but no
dice. So then I changed the jumper on the 'simple' MP-M board so that it
was A-0... plugged it in.. nothing. Finally I took the second MP-M, with
all the fancy jumper wires and piggybacking nonsense. Cannot tell how it is
jumpered or what for, but plugged it in.. boom! Got that prompt. Only one
problem.. it just endlessly repeats itself. I can't type anything or stop
it.
Also, I'm using the MP-C board. After I got that prompt I thought I'd
switch the MP-S in but.. nada.
I'm thinking (hoping) I've just got a wiring issue or something here that is
generating a continuous feedback loop. But I don't know. It could well be
that both the MP-C and MP-S are hooped.
But, that's definitely progress.
I'll post some high-res photos of the boards in that link asap.
Brad
4 p.m.
I am pleased to report I now have the 6800 alive and working.
I discovered one last error I made -- I assumed the cable to be used was a
null modem. It was not.. what we needed was a 'standard modem cable' or
just straight serial. I hooked that up, then looped the DSR/DTS pins on the
cable at the SWTPC end.. voila! I can do all kinds of SWTBUG functions no
problem now.
For fun, I even hooked it up to my SWTPC CT1024. I was pleased to see it
does communicate, albeit with lots of ? marks because the CT1024 is
configured for parity. I guess I'll have to swallow hard, pull the board
(hoping the machine works again after) and change the jumpers to what the
6800 is expecting. Then I can do a video of the two working together, which
as of yet has not been demonstrated on youtube. :)
Thanks to everyone for their helpful suggestions. I'm very lucky this thing
wanted to work. Off to do memory tests and test load some programs.. then
figure out how to bring back in the other mem boards.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Brad H
Sent: Saturday, August 6, 2016 1:44 PM
To: 'General Discussion: On-Topic and Off-Topic Posts'
<cctalk at classiccmp.org>
Subject: RE: SWTPC 6800
Gahh! So close!
https://drive.google.com/folderview?id=0B4pq0-BHd2x6WVFiZHdyMHBlNW8&usp…
ing
The prompt is totally what should be appearing, at least initially. But it
just keeps repeating itself over and over again and doesn't stop.
Notes: I tried jumpering the DRC board to A000 properly this time, but no
dice. So then I changed the jumper on the 'simple' MP-M board so that it
was A-0... plugged it in.. nothing. Finally I took the second MP-M, with
all the fancy jumper wires and piggybacking nonsense. Cannot tell how it is
jumpered or what for, but plugged it in.. boom! Got that prompt. Only one
problem.. it just endlessly repeats itself. I can't type anything or stop
it.
Also, I'm using the MP-C board. After I got that prompt I thought I'd
switch the MP-S in but.. nada.
I'm thinking (hoping) I've just got a wiring issue or something here that is
generating a continuous feedback loop. But I don't know. It could well be
that both the MP-C and MP-S are hooped.
But, that's definitely progress.
I'll post some high-res photos of the boards in that link asap.
Brad
3060
days inactive
3060
days old
4 comments
2 participants
participants (2)
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hilpert＠cs.ubc.ca -
vintagecomputer＠bettercomputing.net