Assembling under DOS-11

[Lars Brinkhoff]

Hello,

I have found some software that was assembled under DOS-11, version 8 or
thereabouts. It was probably written in whatever version of MACRO that
came with DOS at the time. I don't see that it uses any DOS facilities.
It's a version of the Spacewar game for a GT40, written by Lisp guru
Richard C. Waters when working on robotics at MIT.

I would like to assemble and run this software in SIMH.

I tried the "iamvirtual" DOS-11 disk image, but I'm not sure how to
transfer the source code file. I tried to mount the file on SIMH's ptr
device. In DOS I typed RUN PIP, and then DK0:FILE.MAC<PT:. I think
I got an empty file. I also tried the PR: device, same thing. What
am I doing wrong?

I suppose some other version of MACRO-11 would work too. I tried the
PDP-10 PALX cross asembler (because I have it conveniently accessible
from ITS), but it didn't accept the file. I tried macro11 in SIMH'
simtools, but that didn't work either. Any other suggestions?

Thank you,
Lars Brinkhoff

[Ian Hammond]

On Saturday, January 16, 2021 at 9:37:48 PM UTC+11, Lars Brinkhoff wrote:
> Hello,
>
> I have found some software that was assembled under DOS-11, version 8 or
> thereabouts. It was probably written in whatever version of MACRO that
> came with DOS at the time. I don't see that it uses any DOS facilities.
> It's a version of the Spacewar game for a GT40, written by Lisp guru
> Richard C. Waters when working on robotics at MIT.

I thought I had an RT-11 binary for this that I constructed from the stand-alone
version back around 1980 or so when I worked in a lab that had half a dozen GT40 pdp-11s.

Anyway, I found a site with an executable LDA papertape and a simh script to run it at:

https://github.com/PDP-10/its/issues/1780

with the files sw.pt and "gt40", a simh script

So, that might get you up and running under SIMH.

It was great game. We were all addicted. (It also the only GT40 game in town).

I still have an app that converts papertapes (or LDA files in general) into executable
RT-11 images, so I ran it through that to produce SW.SAV, which "might" run under
RT-11 (I haven't tested its functionality in a decade or more).

My guess is that you'll have to reboot after exiting spacewar. I think I solved that
problem way back then, but not tonight.

SW.SAV is stored on my recently active github site:

https://github.com/rust11/rust

in the /kit/ folder


Ian

[Christian Corti]

Ian Hammond <para...@gmail.com> wrote:
> I thought I had an RT-11 binary for this that I constructed from the stand-alone
> version back around 1980 or so when I worked in a lab that had half a dozen GT40 pdp-11s.

That's what we use on our 11/10 with VT11/VR17. I just boot RT11 and
start it with ".R RTLEM" ;-)
I don't know where I had found the RT11 version, but I have the MAC
source and needed to assemble it first.

Christian

[Lars Brinkhoff]

Ian Hammond wrote:
> I found a site with an executable LDA papertape and a simh
> script to run it at:
> https://github.com/PDP-10/its/issues/1780
> with the files sw.pt and "gt40", a simh script
> So, that might get you up and running under SIMH.

It was I who uploaded that zip file. But it's another version of
Spacewar. It was written at Stanford.

What I have now is another Spacewar written at MIT. It's is a plain
ASCII text file with MACRO-11 source code. I want to assemble it.
Maybe using MACRO under DOS-11, or maybe somewhere else. I'm not yet at
liberty to give out copies of the file, but hopefully it will go public
soon.

[Ian Hammond]

Sorry, I got it completely wrong: I was conflating the GT40 lunar lander (LEM) with
Space Wars, which we had only on VT100s. Christian reminded me of RTLEM
and I found its source on-line.

I hunted for GT40 Space War and found what I think you might be referring to as
the Stanford version (Botund Eross) at https://saildart.org/BO as SW.P11. There
was a 2018 comment saying it froze under SimH and perhaps required a GT44
in the thread below:

http://www.vcfed.org/forum/showthread.php?41201-Spacewar-for-PDP-11

I looked at SW.P11 in Notepad and saw a non-standard glyph, which seemed
to start the start and end of lengthy comments. I then read the description
which explained that he cobbled together his own assembler. This file
certainly wouldn't assemble under MACRO-11.

The reason I looked at SW.P11 in Notepad is because DOS text files often have
non-printing ascii codes used to introduce delays for the slow motion of
tab jumps with the early technology. So, that's one way to get some
information about the file you have. The document text might have information
about its build system. If you can get the file into an RT-11 directory then you
can try running it under RT-11 MACRO.

[Ian Hammond]

Actually, that's what I was thinking of. I conflated LEM and VT100 Star Wars. I found the
RT-11 source. I hunted for the macro source and found that Lunar Land has a Wikipedia
entry along with pointer to the RT-11 source code:

https://en.wikipedia.org/wiki/Lunar_Lander_(video_game_genre)
http://www.brouhaha.com/~eric/retrocomputing/dec/gt40/software/moonlander/rtlem.mac

According to Wikipedia, RTLEM was originally written in ten days in 1973 by Jack Burness.
The 1980 Al Kossow port to RT-11 supports a clean exit back to RT-11. In fact, touching
any keyboard key aborts, instantly clearing the screen (which is easy with vector graphics)
and returns to RT-11. Just the thing a gamer needs when your manager walks in unexpectedly.

95% of the work done on a GT40 in our labs used the screen as a command and editing interface.
It was a weird color mixture, but it was a lot better than the earlier cathode ray technology.
A short-lived, but definitely a distinctive and elegant technology. Then we got the pixel.

Ian

[Lars Brinkhoff]

Ian Hammond wrote:

> Lars Brinkhoff wrote:
>> What I have now is another Spacewar written at MIT. It's is a plain
>> ASCII text file with MACRO-11 source code. I want to assemble it.
>> Maybe using MACRO under DOS-11, or maybe somewhere else. I'm not yet
>> at liberty to give out copies of the file, but hopefully it will go
>> public soon.
>

> I hunted for GT40 Space War and found what I think you might be
> referring to as the Stanford version (Botund Eross) at
> https://saildart.org/BO as SW.P11. There was a 2018 comment saying it
> froze under SimH and perhaps required a GT44 in the thread below:
>
> http://www.vcfed.org/forum/showthread.php?41201-Spacewar-for-PDP-11

That is my comment, but it's about the Stanford version. It's the same
as in the sw.zip you found earlier. I found the problem, which was a
missing interrupt vector for the SIMH configuration. It now runs fine
on SIMH.

However, now I want to try the MIT version.

> The reason I looked at SW.P11 in Notepad is because DOS text files
> often have non-printing ascii codes used to introduce delays for the
> slow motion of tab jumps with the early technology. So, that's one way
> to get some information about the file you have. The document text
> might have information about its build system. If you can get the file
> into an RT-11 directory then you can try running it under RT-11 MACRO.

The MIT Spacewar should be written in standard MACRO-11 that came with
DOS-11. I would prefer to assemble it under DOS-11 if possible. It
certainly *should* be possible.

I looked into the error code I got: A003. It's something about a
problem assigning a device. I will look into the manuals to see if I
can figure it out.

Yes, assembling under RT-11 should probably also work. I'm facing
a similar problem there: how do I get the file into the RT-11 system?

[Ian Hammond]

Yes, there's a hole in the bucket and I thought that question must come.

Up until some years ago there was PUTR.COM, a Windows app from John
Wilson, that imported and exported most PDP-11 file formats. Alas Windows
removed support for the memory management model that PUTR used, and
we've been without it ever since. In fact, I've been working on code in that
direction and can probably finishing cobbling up a simple single-file copy app
over the next few days.

There is another way, which is available right now. My RT-11 compatible
operating system RUST/SJ has transparent access to Windows directories.
I've hesitated to mention it because I'm just not quite sure what shape the
distribution, and because installations are always uncomfortable. And
further because some of the documentation is out of date. However, if
you want to try it it's a matter of downloading the zip file, copying it to
the directory "C:\RUST\" and then activating the shell "C:\RUST\SHE.EXE"
SHE prompts with "o":

o define tmp: c:\tmp ! define a Windows directory that has your file
o rt ! start RUST/SJ (using the built-in emulator)
RUST/SJ V3.5

.mount ld: tmp:mydisk ! mount an RT-11 sub disk to hold the file
.copy tmp:myfile.typ ld: ! copy the file from tmp: to ld:

[Alt-C] returns to shell

Somehow, I imagine might not be so straight-forward in practice.

The zip file RUST5.ZIP, and a listing of the RUST/SJ HELP.TXT are here:

https://github.com/rust11/rust/tree/master/kit

[Christian Corti]

Ian Hammond <para...@gmail.com> wrote:
> Up until some years ago there was PUTR.COM, a Windows app from John
> Wilson, that imported and exported most PDP-11 file formats. Alas Windows
> removed support for the memory management model that PUTR used, and

Ehm, PUTR has always been a DOS program, and not an "App" and not for
Windows.

Christian

[Bill Gunshannon]

Last time I tried it ran fine under FreeDOS.

bill

[Scott Lurndal]

Semantics. The Application abbreviation "App" predates mobile phones.

[Christian Corti]

Scott Lurndal <sc...@slp53.sl.home> wrote:
> Semantics. The Application abbreviation "App" predates mobile phones.

Not where I live ;-)

Christian

[Ian Hammond]

I confess that it still feels a little awkward to me when I use the term "app"
to refer to PDP-11 "programs", "tasks", "executable images", ".EXE files",
"CUSPS" (Commonly Used System Programs)", "utilities", and so forth.
However, I think the reason we have so many different names for
essentially the same thing is because we didn't find a term that would
cover them all, and "app" does that. And its short word too.

And given the fact that modern systems have borrowed 90% of their O/S
concepts from the PDP-11/VAX/VMS era, I think that we can return the
compliment from time to time too, as an act of grace :=).

Ian

[pbi...@gmail.com]

It's not merely awkward, it's an anachronistic use of the term and thus necessarily inappropriate and confusing. The referents aren't "essentially the same thing" (IMO) -- each has a specific technical meaning tied to a specific technical context. Smearing all of them into a single ambiguous category isn't helpful ... especially in a technical forum.

Let's use the power of The (Technical) Word, correctly :-}.

[Lars Brinkhoff]

Lars Brinkhoff wrote:
> The MIT Spacewar should be written in standard MACRO-11 that came with
> DOS-11. I would prefer to assemble it under DOS-11 if possible. It
> certainly *should* be possible.
>
> I looked into the error code I got: A003.

It seems this error was due to a disk problem. When I ran VERIFY it
reported a block allocation error.

When I started anew from a fresh DOS-11 disk image I had no problem
reading the files off paper tape (the PR: device) and running MACRO to
assemble them. Likewise punching the output to PP: seems ok, pending
testing of the binary.

[Ian Hammond]

I'm glad someone is making progress! My simple plan to migrate some
PDP-11 Rider/C code to Windows has triggered a long overdue reorganization
of my PDP-11 and Windows libraries (and an ocean of bugs). So, the plan
now is to take my time and produce a generic file exchange utility (NOMAD)
that will run on both Windows and PDP-11 RUST handling file exchange for
RT-11, RSX, XXDP, DOS and VMS. I've got most of the import code I need in
one form or another.