TU58 DECtape-II driver for OS/8

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Bob Armstrong

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Aug 14, 2022, 9:04:37 PMAug 14
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Is there an OS/8 handler for the TU58 DECtape-II? I know DEC never made an official one, but did anybody ever cook one up in their spare time? It looks like it would be a little difficult to fit into two pages, but I've seen people do some amazing things with code size minimization before.

And yes, I am talking about the TU58, the table top (usually, but there was a rack mount option) block addressable, block replaceable, digital cassette drive with a serial RS232 interface and the radial serial protocol. I am NOT talking about the TU55/56 traditional DECtapes, nor the TU60 cassette drives supported by CAPS-8.

Vincent Slyngstad

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Aug 15, 2022, 3:00:58 AMAug 15
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On 8/14/2022 6:04 PM, Bob Armstrong wrote:
> Is there an OS/8 handler for the TU58 DECtape-II? I know DEC never made an official one, but did anybody ever cook one up in their spare time? It looks like it would be a little difficult to fit into two pages, but I've seen people do some amazing things with code size minimization before.
>
> And yes, I am talking about the TU58, the table top (usually, but there was a rack mount option) block addressable, block replaceable, digital cassette drive with a serial RS232 interface and the radial serial protocol. I am NOT talking about the TU55/56 traditional DECtapes, nor the TU60 cassette drives supported by CAPS-8.

I only know about this:
http://www.vandermark.ch/pdp8/local/zread_dir.php?v=OS8&f=OS8-V40/v40-9.1980.pxg
http://www.vandermark.ch/pdp8/local/zread_entry.php?v=OS8&u=OS8-V40/v40-9.1980.pxg&s=88&l=27&d=0&n=TU58NS.PA

Vince

Johnny Billquist

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Aug 15, 2022, 12:04:48 PMAug 15
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On 2022-08-15 03:04, Bob Armstrong wrote:
> Is there an OS/8 handler for the TU58 DECtape-II? I know DEC never made an official one, but did anybody ever cook one up in their spare time? It looks like it would be a little difficult to fit into two pages, but I've seen people do some amazing things with code size minimization before.
>
> And yes, I am talking about the TU58, the table top (usually, but there was a rack mount option) block addressable, block replaceable, digital cassette drive with a serial RS232 interface and the radial serial protocol. I am NOT talking about the TU55/56 traditional DECtapes, nor the TU60 cassette drives supported by CAPS-8.

Don't RSP and MRSP require that you can send break? And unless I
remember wrong, I thought the KL8 was not really capable of sending a
break. But I might be misremembering.
(I think the KL8E could be tricked into sending a break, but have speed
limitations that exclude it, and the KL8JA have a hardware uart
incapable of sending break.)

Johnny

Bob Armstrong

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Aug 16, 2022, 8:39:10 PMAug 16
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On Monday, August 15, 2022 at 9:04:48 AM UTC-7, Johnny Billquist wrote:
> On 2022-08-15 03:04, Bob Armstrong wrote:
> Don't RSP and MRSP require that you can send break? And unless I
> remember wrong, I thought the KL8 was not really capable of sending a
> break

The M8650 can be tricked into sending a break by jamming a continuous stream of zeros into the transmit buffer. That seems to be what this driver does. The M8655 AFAIK cannot send a break..

Thanks, Vince - this is a pretty cool archive that I'd never heard of before.

Bob

William Cattey

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Aug 17, 2022, 10:35:14 PMAug 17
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Willem van der Mark has quite the interesting site. In addition to a PDP-8e emulator in Java with fun animations, and an interesting format for removable media (with converters to the familiar format we use under SIMH), Willem has source and binary of follow-on versions of OS/8 that he created. That 4.0 is, as I understand it, his creation. It contains many subtle improvements that I've not taken time to inventory.

-Bill

William Cattey

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Aug 17, 2022, 10:43:04 PMAug 17
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I forgot to mention that the original OS/8 V3D binary distribution DECtape Images included with the PiDP-8/i software development hosted at tangentsoft.com came from Willem's site as I credit in documentation here: https://tangentsoft.com/pidp8i/dir?ci=tip&name=media/os8

Dennis Boone

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Aug 18, 2022, 4:43:44 PMAug 18
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> Willem van der Mark has quite the interesting site. In addition to a
> PDP-8e emulator in Java with fun animations, and an interesting format
> for removable media (with converters to the familiar format we use under
> SIMH), Willem has source and binary of follow-on versions of OS/8 that
> he created. That 4.0 is, as I understand it, his creation. It contains
> many subtle improvements that I've not taken time to inventory.

Out of curiosity, was P?S-8 lost with the demise of cjl?

De

Vincent Slyngstad

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Aug 18, 2022, 5:23:16 PMAug 18
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On 8/18/2022 1:41 PM, Dennis Boone wrote:
> Out of curiosity, was P?S-8 lost with the demise of cjl?

Not entirely, no. Some colleagues were able to acquire licensing from
his widow, as well as a variety of flash drives and such. In addition,
his old 8/A system, on which he archived a lot of material on a large
hard drive still exists (in a museum). With luck, sometime in the next
year an attempt will likely be made to image that drive, which would
resurrect a number of the older versions, as well as probably
drivers/system heads for the PDP-12, LINC-8, floppies, etc.

I have managed to rebuild, from the material on the flash drives, a
P?S-8 system that I believe is equivalent to the later PEPS released
version (8z). Sources and build trees for the older PEPS version have
not yet been reconstructed.

Likewise with other historical versions. I do believe most of his work
beyond the 8z version (if any of it made it as far as real code) may be
lost.

The PEPS release contained two versions; 8z and an older version (8p,
IIRC). These ran on a version of SIMH on Windows, for those not
familiar with them (PEPS).

For those wondering what the heck P?S-8 is, it's an operating system for
a variety of PDP-8 and similar systems which runs on machines with 4K
and some kind of mass storage. (Currently that needs to be RK05 or
DECtape to run PEPS.) The command language feels a lot like BASIC,
except that the code is usually PDP-8 assembler. The advanced commands
have a syntax that vaguely resembles OS/8, but only vaguely.

Later versions also increasingly resemble COS, for those familiar with that.

Vince

Bob Armstrong

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Aug 19, 2022, 10:20:39 AMAug 19
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On Thursday, August 18, 2022 at 2:23:16 PM UTC-7, Vincent Slyngstad wrote:
> I have managed to rebuild, from the material on the flash drives, a
> P?S-8 system that I believe is equivalent to the later PEPS released
> version (8z). Sources and build trees for the older PEPS version have
> not yet been reconstructed.

Vince - is this version of P?S/8 available anywhere? Out of curiosity, does it still run on real hardware in addition to simh? What specific hardware is supported ? Knowing CJL I imagine he supported every PDP-8 model ever made, maybe with the exception of the 6120 DECmates - he never approved of those.

It might not be widely known, but CJL also contracted with Intersil to write IFDOS, which was the official disk OS for the Intercept systems. Have you found any of that? The Intercepts were 6100 based machines that were largely PDP-8 compatible. Most of the standard DEC paper tape software would work w/o modification, but the only mass storage option was a floppy disk that wasn't RX8 compatible. I have copies of the IFDOS manual, but I've never seen any of the actual software for it.

I always wondered if IFDOS was simply an early version of P?S/8. It'd be great to see that preserved too.

Vincent Slyngstad

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Aug 19, 2022, 12:24:10 PMAug 19
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On 8/19/2022 7:20 AM, Bob Armstrong wrote:
> On Thursday, August 18, 2022 at 2:23:16 PM UTC-7, Vincent Slyngstad wrote:
>> I have managed to rebuild, from the material on the flash drives, a
>> P?S-8 system that I believe is equivalent to the later PEPS released
>> version (8z). Sources and build trees for the older PEPS version have
>> not yet been reconstructed.
>
> Vince - is this version of P?S/8 available anywhere? Out of curiosity, does it still run on real hardware in addition to simh? What specific hardware is supported ? Knowing CJL I imagine he supported every PDP-8 model ever made, maybe with the exception of the 6120 DECmates - he never approved of those.

I have it online in source control, though I haven't written any web
pages about it yet for the so-much-stuff website.

https://svn.so-much-stuff.com/svn/trunk/pdp8/cjl/pasp/
is a link the PASP/PEPS distribution. There's an executable Windows
installer, and a sub-directory there with the contents unpacked for
those who don't use Windowa or want to browse it without installing it
first. (It's basically a version of SIMH and a bunch of media images
with their SIMH setup scripts. And a lot of Windows shortcuts, which I
know he spent a lot of time on, but that I never used.)

Next door in https://svn.so-much-stuff.com/svn/trunk/pdp8/cjl/pqs8/
are build trees for 8u and 8z. The 8u directory doesn't do anything
yet. The 8z directory has a start toward a cross-assembly build, but
that isn't finished either.

In the 8z/simh directory and sub-directories is the actual build, which
consists of several scripts run under SIMH to perform a native build
from source, then patch the binaries to match the PEPS distribution of
8z. This working build is for DECtape.

The PEPS distribution contains a "new" and an "old" release for RK05 and
for DECTape. The DECtape versions have been patched to rewind
differently than the sources, which was supposed to be an optimization
for the SIMH environment. (Effectively it simulates a keyboard ^R
"rewind" before each prompt, if I'm remembering correctly.)

While the code is CPU agnostic, even to the point of working on
DECmates, the system head is usually TC01/TC08 DECtape. P?S-8 supports
8 units in the system driver, so you get a pretty tricked out system for
that device. Unfortunately, support for other devices is mostly lame.
The drivers are there and installed, but the only utilities that know
how to load and use them are meant to migrate things to and from the
system device.

The exceptions are the console and line printer, which are system calls
and so supported on every system head. Alas, not so the paper tape
reader. (CJL clearly thought paper tape to be awful, but really loved
printing.)

Files on P?S-8 are also "odd" to folks who are used to OS/8 or the like.
They are always 4K. Text files have line numbers, and the built-in
editor allows you to retype, insert, and delete lines, much as you would
expect from a BASIC interpreter. The assembler converts from one to
several such files into a 4K binary file. Doing anything with larger
files or non-system devices is quite baroque, and really requires
knowledge of the P?S-8 internals.

There are two directories. The DIRectory contains system programs, and
files are generally created there only at install time, by directly
editing the media. The CATalog contains all the user's 4K files, and is
where the user is expected to work.

> It might not be widely known, but CJL also contracted with Intersil to write IFDOS, which was the official disk OS for the Intercept systems. Have you found any of that? The Intercepts were 6100 based machines that were largely PDP-8 compatible. Most of the standard DEC paper tape software would work w/o modification, but the only mass storage option was a floppy disk that wasn't RX8 compatible. I have copies of the IFDOS manual, but I've never seen any of the actual software for it.
>
> I always wondered if IFDOS was simply an early version of P?S/8. It'd be great to see that preserved too.

IFDOS is indeed an earlier version of P?S-8. There are files for an old
floppy version, but I'm not sure if it is exactly IFDOS or something
later. I'm also not sure how complete it is.

Vince

Bob Armstrong

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Aug 20, 2022, 10:31:49 AMAug 20
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On Friday, August 19, 2022 at 9:24:10 AM UTC-7, Vincent Slyngstad wrote:
> https://svn.so-much-stuff.com/svn/trunk/pdp8/cjl/pasp/
> ...

This is great - thank you for putting this online, VInce!

What's "L8EBAS" (mentioned in the PASP/PEPS area)? Is that a LINC-8 extended BASIC? Did CJL write such a thing? Is that in there too? I don't see any files for it.

And you mentioned that you had found some IFDOS files, but I take it that those aren't online yet?

Thanks again!

Vincent Slyngstad

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Aug 20, 2022, 4:35:50 PMAug 20
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On 8/20/2022 7:31 AM, Bob Armstrong wrote:
> On Friday, August 19, 2022 at 9:24:10 AM UTC-7, Vincent Slyngstad wrote:
>> https://svn.so-much-stuff.com/svn/trunk/pdp8/cjl/pasp/
>> Next door in https://svn.so-much-stuff.com/svn/trunk/pdp8/cjl/pqs8/
>> ...
>
> This is great - thank you for putting this online, VInce!

You're welcome. I've been wanting to see P?S-8 out there for a while,
and to see what the fuss was about.

> What's "L8EBAS" (mentioned in the PASP/PEPS area)? Is that a LINC-8 extended BASIC? Did CJL write such a thing? Is that in there too? I don't see any files for it.

It's the LAB-8/E Basic. Not sure that was pulled from PASP/PEPS, but
perhaps he couldn't be bothered to verify the license?

> And you mentioned that you had found some IFDOS files, but I take it that those aren't online yet?

There are a variety of flash drives that were recovered, but not put
directly online. CJL has some private correspondence in there, and some
of it is "strongly worded". So there is a feeling that it probably
isn't appropriate to redistribute everything.

Vince

Vincent Slyngstad

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Aug 20, 2022, 5:58:32 PMAug 20
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On 8/20/2022 7:31 AM, Bob Armstrong wrote:
> And you mentioned that you had found some IFDOS files, but I take it that those aren't online yet?

I had a look through the floppy files, and they appear to be related to
the "MDC8". There's a special version of dumprest and some images. I
think these have to do with Charles' efforts to recover the source code
from his 8/A development system. I suspect "MDC8" is the controller he
was using for his big Winchester hard drive, and it's associated floppy
backup media.

Alas, I don't see anything that's recognizably IFDOS related.

Vince

Bob Armstrong

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Aug 20, 2022, 11:02:45 PMAug 20
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On Saturday, August 20, 2022 at 2:58:32 PM UTC-7, Vincent Slyngstad wrote:
> Alas, I don't see anything that's recognizably IFDOS related.

Ah well, thanks for checking. It's mostly a matter of curiosity that I'm interested - judging from the manual that I have, IFDOS is somewhat, uh, primitive. Especially compared to OS/8 at the time.

Johnny Billquist

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Aug 21, 2022, 10:23:36 AMAug 21
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On 2022-08-20 23:58, Vincent Slyngstad wrote:
> On 8/20/2022 7:31 AM, Bob Armstrong wrote:
>>    And you mentioned that you had found some IFDOS files, but I take
>> it that those aren't online yet?
>
> I had a look through the floppy files, and they appear to be related to
> the "MDC8".  There's a special version of dumprest and some images. I
> think these have to do with Charles' efforts to recover the source code
> from his 8/A development system.  I suspect "MDC8" is the controller he
> was using for his big Winchester hard drive, and it's associated floppy
> backup media.

Very vague recollection is that MDC8 was the SCSI controller he had for
the PDP-8. But this could be a false memory. If needed, I can go and
search through old mails I have. I know he talked about that a few times
with me many years ago.

Johnny

Dennis Boone

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Aug 21, 2022, 12:23:29 PMAug 21
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> Very vague recollection is that MDC8 was the SCSI controller he had for
> the PDP-8. But this could be a false memory. If needed, I can go and
> search through old mails I have. I know he talked about that a few times
> with me many years ago.

From an old a.s.p post.

De

============

From: van...@vsta.org
Newsgroups: alt.sys.pdp8
Subject: Re: PDP8 FPGA and RK8E
Date: 13 Apr 2012 21:30:34 GMT

Comments from Charles Lasner attached...

I've finally got my PDP8 FPGA running OS/8 with a RK8E compatible
controller front-ending a SD card as a set of RK05 disk drives.

I would be quite interested in what you've accomplished, and what
potential peripherals could be added on. The RK8E is a good starting
point, but hardly where I would stop. Moreover, you should get the
specs on the RKS8E which allows for up to 8 drives, which would be a
little more useful than 1 or 2 or 4. My personal system is based on a
Seagate ST-4096 through the CESI MDC8 SCSI controller that supplies 64
real MB equivalent to the PDP-8/a-e [in two chassis with a BC80-C cable
between them]. Also have an RK8E and two drives on the same machine
[and DECtapes and RX01 superset and lotsa other goodies.]

Vincent Slyngstad

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Aug 21, 2022, 3:29:02 PMAug 21
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On 8/21/2022 9:20 AM, Dennis Boone wrote:
> > Very vague recollection is that MDC8 was the SCSI controller he had for
> > the PDP-8. But this could be a false memory. If needed, I can go and
> > search through old mails I have. I know he talked about that a few times
> > with me many years ago.
>
> From an old a.s.p post.

That's the one. The driver I have structures the device as the
equivalent of 30+ partitions, each the same size as an RK05 partition.
It is interesting, in that that is far more than any OS/8 can support,
so you have to pick which partitions when you build the driver. Which
partitions are available then depends on which partition you booted.

I'd also love to see information about the MDC8 board itself.

Vince


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