• Please review our updated Terms and Rules here

Can I run an RL02 on a PDP-8/M???

A

AteEm

Experienced Member
Joined
Aug 1, 2013
Messages
111
I have a working PDP-8/M and PDP-8/A. The 8/A has an RL8A controller running an RL02 drive.

My goal is to run TSS/8 (Time Share System 8) on the /M to be able to play Lunar Lander:)
The thing is, I don't have any drive on the /M so there's no way to run any OS.
So, it looks like the RL8A controller is hex wide (fits the /A buss), but rumor has it that two of the edge tabs are not actually used. That is, if I move the fans to the outside of the /M cabinet I think the RL8A will plug into the OMNIBUS using the four 'active' tabs, and the other two tabs will 'hang free.'

Does anyone know if that will actually work? Or do I have to find an RK8E controller and RK05 drive?

Thanks!

Mike
 
Theoretically it can be done. I wanted to run it on my 8e. But trying to use any disk but an RF08/RS08 or DF32/DS32 makes it much
more difficult. These drives can read/write in increments of one word. Later devices read/write blocks of data at 128 or 256 words
at a time. One would have to modify the disk I/O routines to buffer data if you need to read/write less than the block size. I started
down that path, but never got too far. Maybe if there was an emulated RF08 or DF32 this would be much easier. Between a bunch of
us we did get the 8.22 source corrected to match the one image available. Maybe you'll come up with a solution I didn't think of.
So let us know your progress on this. I'd love to see it run on a newer 8 (8e, 8f, 8m).
Tim Radde
 
Thanks for your feedback.
It sounds like this is more of an OS driver/software problem than hardware?
I.e., the physical plugging in the hex wide card into the quad wide 8m chassis should be okay?
(My main concern at this point is knowing that I won't blow up anything on the controller or something else in my 8m box)

tradde said:
Theoretically it can be done. I wanted to run it on my 8e. But trying to use any disk but an RF08/RS08 or DF32/DS32 makes it much
more difficult. These drives can read/write in increments of one word. Later devices read/write blocks of data at 128 or 256 words
at a time. One would have to modify the disk I/O routines to buffer data if you need to read/write less than the block size. I started
down that path, but never got too far. Maybe if there was an emulated RF08 or DF32 this would be much easier. Between a bunch of
us we did get the 8.22 source corrected to match the one image available. Maybe you'll come up with a solution I didn't think of.
So let us know your progress on this. I'd love to see it run on a newer 8 (8e, 8f, 8m).
Tim Radde
Click to expand...
 
AteEm said:
Thanks for your feedback.
It sounds like this is more of an OS driver/software problem than hardware?
I.e., the physical plugging in the hex wide card into the quad wide 8m chassis should be okay?
(My main concern at this point is knowing that I won't blow up anything on the controller or something else in my 8m box)
Click to expand...
No, it's all software. The RL8a can be used in non 8a system, you just need to put it on
an extender like Lou did. To run TSS/8 with a non word addressable disk you have to modify
the code to buffer 256 word reads/writes and only use the portion you need. Not a terribly
difficult task, but find room to add the extra code might be a bit hard. TSS/8 uses almost
all of each page it uses.

I am sure Lou will post some pics of his once he reads this. I never managed to find an RL8a when
I had my 8a.
 
Good point about how packed in the TSS/8 code is. I hadn't thought about that...
Well, I guess we'll see how good of a code monkey I am!

The RL02 boots OS8 on the 8/A... Will it boot on the 8/E without any modification? That may be an easier way to start and verify all the hardware is happy.
Then I can work on figuring out TSS/8.

tradde said:
No, it's all software. The RL8a can be used in non 8a system, you just need to put it on
an extender like Lou did. To run TSS/8 with a non word addressable disk you have to modify
the code to buffer 256 word reads/writes and only use the portion you need. Not a terribly
difficult task, but find room to add the extra code might be a bit hard. TSS/8 uses almost
all of each page it uses.

I am sure Lou will post some pics of his once he reads this. I never managed to find an RL8a when
I had my 8a.
Click to expand...
 
AteEm said:
Good point about how packed in the TSS/8 code is. I hadn't thought about that...
Well, I guess we'll see how good of a code monkey I am!

The RL02 boots OS8 on the 8/A... Will it boot on the 8/E without any modification? That may be an easier way to start and verify all the hardware is happy.
Then I can work on figuring out TSS/8.
Click to expand...
If you solve this problem I would like to see your
solution. You'll want to start with a copy of the "corrected" 8.22 code. There were a few bugs and
typos in it. Of course it was hand typed in from a listing. I would expect it to boot Ok, but if any
code read/writes smaller/larger than 256 words you could overwrite something important. I never
tried to boot it on my 8e as I only had RK05s. I started to think about plans to modify TSS/8, but
never got very far. I used TSS/8 back in 1969-1974. I still would like to be able to run it on
real hardware, of course an 8i being my preferred machine. I don't have any real pdp-8 hardware
at this time, so that's a problem in itself. :) If you'd like a copy send me a private IM and I can
arrange to send you the ZIP file I have.
 
I was a little later: 1972-1978 for me!

Our school system had a 8/E running TSS/8 that supported 16 'users' (ASR33s) hooked up by 110 baud acoustic modems; the various junior and senior high schools that were in school district.

How, as a 16 year old I had the presence of mind to track down the system manager at the district office (where the computer resided) and got him to print out the source code is beyond me. But, here I am 40 something years later with the 132 column green-bar (in excellent condition, I might add) of TSS/8 source code with the DEC programmers' comments, version 8.24, sitting right in front of me as I type this!:p The line printer shows it was dumped on July 31, 1976 at 13:52:41.

Now, how I'm going to get that into a file that I can cross-assemble is a whole 'nother question!
So, I'll send you a PM with my email as I'd appreciate a copy of your corrected 8.22; it will be interesting to see how it compares to v8.24.

Thanks!


tradde said:
If you solve this problem I would like to see your
solution. You'll want to start with a copy of the "corrected" 8.22 code. There were a few bugs and
typos in it. Of course it was hand typed in from a listing. I would expect it to boot Ok, but if any
code read/writes smaller/larger than 256 words you could overwrite something important. I never
tried to boot it on my 8e as I only had RK05s. I started to think about plans to modify TSS/8, but
never got very far. I used TSS/8 back in 1969-1974. I still would like to be able to run it on
real hardware, of course an 8i being my preferred machine. I don't have any real pdp-8 hardware
at this time, so that's a problem in itself. :) If you'd like a copy send me a private IM and I can
arrange to send you the ZIP file I have.
Click to expand...
 
AteEm said:
I was a little later: 1972-1978 for me!

Our school system had a 8/E running TSS/8 that supported 16 'users' (ASR33s) hooked up by 110 baud acoustic modems; the various junior and senior high schools that were in school district.

How, as a 16 year old I had the presence of mind to track down the system manager at the district office (where the computer resided) and got him to print out the source code is beyond me. But, here I am 40 something years later with the 132 column green-bar (in excellent condition, I might add) of TSS/8 source code with the DEC programmers' comments, version 8.24, sitting right in front of me as I type this!:p The line printer shows it was dumped on July 31, 1976 at 13:52:41.

Now, how I'm going to get that into a file that I can cross-assemble is a whole 'nother question!
So, I'll send you a PM with my email as I'd appreciate a copy of your corrected 8.22; it will be interesting to see how it compares to v8.24.

Thanks!
Click to expand...

we had a heavily modified version of 8.25 at the University of Wisconsin, Milwaukee.
/TSS-8.25 CONFIGURATION FOR UWM
/CONFIGURATION PARAMETERS FOR THE TSS/8 MONITOR
/COPYRIGHT 1971 - DIGITAL EQUIPMENT CORPORATION; MAYNARD, MASS.
/

which you can find under
http://bitsavers.org/bits/DEC/pdp8/ascii/

along with John Wilson's version.

we also had the sources to BASIC, which was apparently quite rare.

I think the corrected 8.22 is in here:
http://www.heeltoe.com/download/pdp8/README.html
 
Sorry guys, been very busy at work lately.

Jack indeed posted the right photo of my RL8A hanging out of the top of the 8/e. It's in a quad-height, double width card extender. That works fine in the 8/e and would be the same in an 8/m. I can either toggle the bootstrap in from the programer's console, or I'll first boot OS/8 from RX01 (built with RX and RL handlers) using the RX01 bootstrap in my MI8E diode bootstrap rom, then boot the RL. Someday I want to find another MI8E to configure with the RL8A bootstrap.

So, this setup does work fine.

Would TSS/8 have RL handlers???


Lou
 
Al Kossow said:
we had a heavily modified version of 8.25 at the University of Wisconsin, Milwaukee.
/TSS-8.25 CONFIGURATION FOR UWM
/CONFIGURATION PARAMETERS FOR THE TSS/8 MONITOR
/COPYRIGHT 1971 - DIGITAL EQUIPMENT CORPORATION; MAYNARD, MASS.
/

which you can find under
http://bitsavers.org/bits/DEC/pdp8/ascii/

along with John Wilson's version.

we also had the sources to BASIC, which was apparently quite rare.

I think the corrected 8.22 is in here:
http://www.heeltoe.com/download/pdp8/README.html
Click to expand...

I hadn't known the 8.25 code was anywhere. I knew some of 8.24 was but it seemed
choppy when I saw it and may have only been the monitor portion. Does the newer 8.24
or 8.25 support RK05s as the swap space? Maybe with one of those the OP won't have
to change anything? My local college updated to 8.24 a few months before I graduated
there with my two year degree. I don't know if it supported RK05s or not. Our system
was a very big 8i with 3 RS08s as the main disks.

Al's URL links are correct and were where I would have pointed you to and where I downloaded
the corrected 8.22 version myself. Thanks for the other link.
 
Lou - N2MIY said:
Sorry guys, been very busy at work lately.

Jack indeed posted the right photo of my RL8A hanging out of the top of the 8/e. It's in a quad-height, double width card extender. That works fine in the 8/e and would be the same in an 8/m. I can either toggle the bootstrap in from the programer's console, or I'll first boot OS/8 from RX01 (built with RX and RL handlers) using the RX01 bootstrap in my MI8E diode bootstrap rom, then boot the RL. Someday I want to find another MI8E to configure with the RL8A bootstrap.

So, this setup does work fine.

Would TSS/8 have RL handlers???


Lou
Click to expand...

That I don't know. I'd be interested to hear.
 
Thank you, Al!

Got everything downloaded.
Al Kossow said:
we had a heavily modified version of 8.25 at the University of Wisconsin, Milwaukee.
/TSS-8.25 CONFIGURATION FOR UWM
/CONFIGURATION PARAMETERS FOR THE TSS/8 MONITOR
/COPYRIGHT 1971 - DIGITAL EQUIPMENT CORPORATION; MAYNARD, MASS.
/

which you can find under
http://bitsavers.org/bits/DEC/pdp8/ascii/

along with John Wilson's version.

we also had the sources to BASIC, which was apparently quite rare.

I think the corrected 8.22 is in here:
http://www.heeltoe.com/download/pdp8/README.html
Click to expand...
 
Good to hear.
I'm going to start by making sure my 8a will still boot OS8 off the RL02. It's been 5 years since I've turned on either the 8m or 8a :(

Then I'll try the extender card trick to move the RL8A/RL02 over to the 8m.
See if OS8 will boot on the 8m after toggling in the bootstrap (no RXs on my system).
If that all works, I'll move on to TSS/8.
Am I going to be able to create a 'dual boot', TSS/8 or OS8, system off of a single RL02 pack?

Lou - N2MIY said:
Sorry guys, been very busy at work lately.

Jack indeed posted the right photo of my RL8A hanging out of the top of the 8/e. It's in a quad-height, double width card extender. That works fine in the 8/e and would be the same in an 8/m. I can either toggle the bootstrap in from the programer's console, or I'll first boot OS/8 from RX01 (built with RX and RL handlers) using the RX01 bootstrap in my MI8E diode bootstrap rom, then boot the RL. Someday I want to find another MI8E to configure with the RL8A bootstrap.

So, this setup does work fine.

Would TSS/8 have RL handlers???


Lou
Click to expand...
 
AteEm said:
I was a little later: 1972-1978 for me!

Our school system had a 8/E running TSS/8 that supported 16 'users' (ASR33s) hooked up by 110 baud acoustic modems; the various junior and senior high schools that were in school district.

How, as a 16 year old I had the presence of mind to track down the system manager at the district office (where the computer resided) and got him to print out the source code is beyond me. But, here I am 40 something years later with the 132 column green-bar (in excellent condition, I might add) of TSS/8 source code with the DEC programmers' comments, version 8.24, sitting right in front of me as I type this!:p The line printer shows it was dumped on July 31, 1976 at 13:52:41.

Now, how I'm going to get that into a file that I can cross-assemble is a whole 'nother question!
So, I'll send you a PM with my email as I'd appreciate a copy of your corrected 8.22; it will be interesting to see how it compares to v8.24.

Thanks!
Click to expand...

If you can get it scanned, there is someone (James Markevich) who has custom OCR software optimized for line printer listings.
Do you have just the monitor, or the utility printouts as well?
 
Sadly, I only have the two parts to the monitor; it turns out I don't even have INIT, SI, or FIP.
I've been assembling the downloads you linked to and have used my copy of TS8 to correct a couple of errors. Unfortunately, I have undefined symbol errors in both FIP and SI that I can't track down...
Hopefully, I'll get a chance over the Holidays to fire up the 8m and see what luck I have with the RL02.
However, looking over the OS code is not encouraging with regards to writing a driver for the RL02.

Al Kossow said:
If you can get it scanned, there is someone (James Markevich) who has custom OCR software optimized for line printer listings.
Do you have just the monitor, or the utility printouts as well?
Click to expand...
 
You must log in or register to reply here.
Back
Top