Zork for the PDP-11 / RT-11 recreated

I know this is a weird one, but I’ve always wanted to run Infocom games from ever since I found out it was a thing.

The cover of the RT-11 Zork that sold on ebay for $2,348.31

I know you maybe thinking of the FORTRAN port of the full Zork game, which does run on the same system. But this is NOT the FORTRAN reverse engineered game, rather it’s a port of the Z-Machine to the RT-11 / PDP-11.

Also this is NOT a 3rd party reverse engineering effort, it is the official Infocom Z-Machine source.

;       Proprietary documentation of:
;               Infocom, Inc.
;               55 Wheeler St.
;               Cambridge, MA 02138
;       Copyright (C) 1982, 1983 Infocom, Inc.  All rights reserved.

Yes it’s the real deal!

Ok so what or where to do this?! First you need SIMH or any other good PDP-11 emulator, a copy of RT-11, and of course the source to the interpreter oddly enough named PDP11.ZIP. Just keep in mind that this is NOT a pk-zip file, it’s a text file. It’s Macro-11 assembler source.

First you need a very simple config/type in to the SIMH PDP-11 emulator:

attach rk0 rtv4_rk.dsk
attach ptr pdp11.zip
boot rk

All being well you should boot into RT-11.

Now we copy the source into the machine through the paper tape reader. Just type in ‘COPY PC: ZIP.MAC’

 Files copied:
PC:            to DK:ZIP.MAC


This will create a .mac or macro assembler source file. The extension matters as it will tell the compiler what file it is and what to do. But luckily this is a single file, and assembles quite easily. As a tip to Unix folk, I found that making the assembly source in MS-DOS CR/LF made life easier.

Compiling & linking is very straightforward




Now we need to import a game file. I usually test with Planetfall, so I grabbed the data file, and placed it into the working directory and then attached it to the emulator

Simulation stopped, PC: 152644 (BR 152622)
sim> att ptr planetfa
sim> c

 Files copied:
PC:            to DK:PLANET.IML


Notice the filenames are short, very 8.3 for some strange coincidence! Also I named it planet.iml, as that is what the interpreter is expecting. Now we can just run the zip and point it to the game data file!

Line width (default is 80, end with LF for status line):
File name (current default is DK:$GAME$.IML) *dk:planet.iml
Infocom interactive fiction - a science fiction story
Copyright (c) 1983 by Infocom, Inc. All rights reserved.
PLANETFALL is a trademark of Infocom, Inc.
Release 37 / Serial number 851003

And there we go! We are now running Planetfall on our simulated PDP-11!

There is quite a few great 80’s systems in the github repository, I have no doubt the rest can be built, but I thought I’d tackle a system that was another bigfoot, a thing of pure legend!

Building MS-DOS 2.11

I thought I’d slap together some github thing with MS-DOS 2.11 that’s been made buildable thanks to a whole host of other smart people. The default stuff out there expects you to build it under MS-DOS using the long obsoleted ‘append’ utility which can add directories to a search path. Instead I created a bunch of makefiles that take advantage of MS-DOS Player, and let you build from Windows.

dos211: just the MS-DOS 2.11 sources, I re-aranged stuff and made it (slightly) easier to rebuild on Windows. (github.com)

building should be somewhat straightforward, assuming you have the ms-dos player in your path. JUST MAKE SURE YOU UNZIP as TEXT mode. If you are getting a million errors you probably have them in github’s favourite unix mode.

msdos ..\tools\masm ibmbio.asm ibmbio.obj NUL NUL
The Microsoft MACRO Assembler , Version 1.25
 Copyright (C) Microsoft Corp 1981,82,83

Warning Severe
Errors  Errors
0       0
msdos ..\tools\masm sysimes.asm sysimes.obj NUL NUL
The Microsoft MACRO Assembler , Version 1.25
 Copyright (C) Microsoft Corp 1981,82,83

Warning Severe
Errors  Errors
0       0
msdos ..\tools\masm sysinit.asm sysinit.obj NUL NUL
The Microsoft MACRO Assembler , Version 1.25
 Copyright (C) Microsoft Corp 1981,82,83

DOSSYM in Pass 2

Warning Severe
Errors  Errors
0       0

   Microsoft Object Linker V2.00
(C) Copyright 1982 by Microsoft Inc.

Warning: No STACK segment

There was 1 error detected.
msdos ..\tools\exe2bin.exe IBMBIO IBMBIO.COM < 70.TXT
Fix-ups needed - base segment (hex): 70
del -f ibmbio.obj    sysimes.obj   sysinit.obj ibmbio.exe


As an example building the bios by running make. For the impatiend you can download dos211.zip, which includes a bootable 360kb disk image, and a 32Mb vmdk!

FOSBIC1 compiler

Or Basic compiler/system in Fortran IV

I came across fosbic1 on github by accident, so intrigued by the description:

This is the FOSBIC1 compiler developed at the University of Gie├čen, Germany
in the late 70s for the CDC 3300 batch system.

It is a BASIC compiler and runtime system which is written in FORTRAN IV.

The text book from which the source code was copied implies that it is
a modified version of a BASIC compiler named UWBIC from the University of Washington, developed by William Sharp in 1967, for their IBM 7094.

So, without going into it much further I went ahead and made a few minor changes to get it running on Microsoft Fortran


Instead of some boring example, I thought I’d try some Mandelbrot, so going through this collection on rosettacode, I thought the OS/8 version looked simple enough to work with.

Sadly it doesn’t seem to be very ASCII so it doesn’t understand numerical characters. Maybe I’m doing it wrong I didn’t see anything. Just as my attempt to set a string variable to itself + a new letter then print that string strangely failed. Also it does weird stuff with strings, again it maybe me, but I’m impatient. This is terrible, and yeah I know.

                                        TESTCOMPILER -- BASIC BWL 5 GIESSEN -- VERSION 6/76-04

                   10 X1=59
                   11 Y1=21
                   20 I1=-1.0
                   21 I2=1.0
                   22 R1=-2.0
                   23 R2=1.0
                   30 S1=(R2-R1)/X1
                   31 S2=(I2-I1)/Y1
                   40 FOR Y=0 TO Y1
                   50 I3=I1+S2*Y
                   60 FOR X=0 TO X1
                   70 R3=R1+S1*X
                   71 Z1=R3
                   72 Z2=I3
                   80 FOR N=0 TO 30
                   90 A=Z1*Z1
                   91 B=Z2*Z2
                   100 IF A+B>4.0 GOTO 130
                   110 Z2=2*Z1*Z2+I3
                   111 Z1=A-B+R3
                   120 NEXT N
                   130 REM PRINT CHR$(0062-N);
                   131 IF N=0  THEN 200
                   132 IF N=1  THEN 202
                   133 IF N=10 THEN 204
                   134 IF N=11 THEN 206
                   135 IF N=12 THEN 208
                   136 IF N=14 THEN 210
                   137 IF N=15 THEN 212
                   138 IF N=16 THEN 214
                   139 IF N=17 THEN 216
                   140 IF N=19 THEN 218
                   141 IF N=2  THEN 230
                   142 IF N=20 THEN 232
                   143 IF N=22 THEN 234
                   144 IF N=23 THEN 236
                   145 IF N=24 THEN 238
                   146 IF N=25 THEN 240
                   147 IF N=3  THEN 242
                   148 IF N=30 THEN 244
                   149 IF N=31 THEN 246
                   150 IF N=4  THEN 248
                   151 IF N=5  THEN 250
                   152 IF N=6  THEN 252
                   153 IF N=7  THEN 254
                   154 IF N=8  THEN 256
                   155 IF N=9  THEN 258
                   200 PRINT 'A';
                   201 GOTO 439
                   202 PRINT 'B';
                   203 GOTO 439
                   204 PRINT 'C';
                   205 GOTO 439
                   206 PRINT 'D';
                   207 GOTO 439
                   208 PRINT 'E';
                   209 GOTO 439
                   210 PRINT 'F';
                   211 GOTO 439
                   212 PRINT 'G';
                   213 GOTO 439
                   214 PRINT 'H';
                   215 GOTO 439
                   216 PRINT 'I';
                   217 GOTO 439
                   218 PRINT 'J';
                   219 GOTO 439
                   230 PRINT 'K';
                   231 GOTO 439
                   232 PRINT 'L';
                   233 GOTO 439
                   234 PRINT 'M';
                   235 GOTO 439
                   236 PRINT 'N';
                   237 GOTO 439
                   238 PRINT 'O';
                   239 GOTO 439
                   240 PRINT 'P';
                   241 GOTO 439
                   242 PRINT 'Q';
                   243 GOTO 439
                   244 PRINT 'R';
                   245 GOTO 439
                   246 PRINT '-';
                   247 GOTO 439
                   248 PRINT 'T';
                   249 GOTO 439
                   250 PRINT 'U';
                   251 GOTO 439
                   252 PRINT 'V';
                   253 GOTO 439
                   254 PRINT 'W';
                   255 GOTO 439
                   256 PRINT 'X';
                   257 GOTO 439
                   258 PRINT 'Y';
                   259 GOTO 439
                   439 REM
                   440 NEXT X
                   450 PRINT '-EOL'
                   460 NEXT Y
                   461 PRINT 'END'
                   470 END

It runs in batches, so it’s not interactive. Very mainframe/1960’s minicomputer like. I guess it’s fitting again being in FORTRAN.

******************* EVERYTHING SEEMS OK -- LET'S GO AHEAD

                    PERCENT OF AVAILABLE STORAGE USED               31.081
                    PERCENT OF AVAILABLE DATA STORAGE USED            .000

AA    A    A    A    A    B    B    B    B    B    K    K    K    K    K
K    K    K    K    K    K    K    K    K    K    Q    Q    Q    Q    Q
Q    T    T    T    U    X    F    D    E    T    Q    Q    Q    Q    K
K    K    K    B    B    B    B    B    B    B    B    B    B    B    -EOL

I’m not sure what is up with the AA and after that, it’s all tabulated. I ended up running it through sed to remove the spaces, and using notepad to stitch the lines together. I guess I could have bash’d it some more but.. I’m impatient.

So yeah, it looks like it worked! Very amazing. And of course it’s crazy fast but that should be expected I suppose. I don’t like the hard coded table, but I just wanted to get it to generate an image.

Sadly, the author of the compiler, Weber seems to have disappeared, and the publisher Paul Haupt died in 1978, a year after this being published.

Missing Neko98

Neko on ARM

With the collapse of my vpsland archive, Neko has become lost once more again. Thankfully I had some fragment backups so I have been able to bring Neko back from the grave. again.

First I dumped everything I had over on sourceforge. With a bit more digging I found the old RISC versions as well. I even found the Itanium version, although I lost the ARM version. Im not sure I have an 8gb pi4 anymore, but I’d like to get one when/if prices stop being insane. Anyways I also uploaded the source to github, since it’s more hip and acceptable for zoomers. I do have to say the git mirror command was everything I’d hoped it’d be.

git push --mirror https://github.com/neozeed/neko98.git

It literally was that easy.

I put a binary built with Visual C++ 2010 SP1 over there too. Although if you need Visual C++ 2010 runtimes, I put them on sourceforge.

Also I should add in the settings make sure you click “Always On Top”, otherwise Neko will be hidden to the desktop surface and you won’t see him.

I hope you enjoy!

Missing link for Basilisk I found

Actually I held onto this, as I wanted to do something crazy for that Marchintosh thing but life got in the way it fell by the wayside, and well now it’s September, and I already have a Qemu instance running A/UX so my ‘at best’ hope of Basilisk II with MMU emulation is all but moot.

Captain, oh Captain!

While it may look like 2 very old emulators, which they are, the interesting thing here is that this old version of Basilisk that only has Macintosh Classic emulation is using the 68000 emulation core from UAE 0.6.8. It took a lot of downloading stuff, a lot of other nonsense, but I eventually found it, and was able to diff around to find the changes made were rather inconsequential, there by letting me rebuild UAE back on top of Basilisk.

My plan had been to either use far newer UAE cpu core, say from Previous as it has working MMU support, or Musashi.

I was building hard coded for TDM GCC 5.1.0 on MinGW. It doesn’t matter anymore but I threw it up on github since that is where all the cool kids are.


It’s absolutely pointless I guess, but maybe someone will find it interesting.

Netscape 3.02 aka hiding in plain site

Much to my surprise, along with a few other people the partial source code to Netscape 3 has been found. But it’s been there since 2011.

Normally I look for ‘source code’ although that terrible movie overlaps the name making it hard to find. So the phrase for the last decade turns out to be ‘source tree’

Netscape Communicator 3.0.2 Source Tree

So who knew!?

The SDK stuff is missing, and it looks like the Windows stuff is intermixed with the Unix.

There is some CVS tags, but not the history. Lots of the crypto has been deleted, and the SDK stuff is missing. Also no cooltalk. SUN Java is there oddly enough.

I have no idea if it’s buildable as it looks like its expecting a magical config regarding paths and tools, and a quick glance looks like it’ll need some time to massage.

Could this be the dawn of the ‘will it run NetScape 3’?

Sandboxie went GPL3!

I’ve been using Sandboxie for a long while to run all those questionable downloads on Windows. It’s a great light weight sandbox (as the name implies) for running random downloads, or even going to questionable websites as Sandboxie does a great job of isolating processes, and their filesystem access.

It’s not been all that cheap, but I felt it was worth it. I went to check to see how much it is as the conversation had come up on discord, and it turns out that Sophos had bought Sandboxie, and opened up the source code!

The downside is that there will be no further official development of the product. So I guess at some point I’ll have to break down and get a signing cert and re-build it if I want to keep using it.

Last version is locally mirrored here, as I understand it’ll be deleted soon enough.


GCC moved to git!

After all that flap about having moved GCC into GIT I thought it would be worth checking out, you know digging for interesting old artifacts.

I found the ‘start’ back over here on github:

Sadly the ‘initial revisions’ only contain a few files, far from the contents of the ’87 archive.


Not that I would envy anyone crazy enough to do such a thing, I was just hoping someone else would have done a better job than I did.

Sourcetrail is now GPL!

Okay, so it actually happened on November 18, 2019 but here we are!

From their blog:

I am happy to announce that all our founding members agreed to turn Sourcetrail, our cross-platform source explorer, into free and open-source software. The source code is now available on GitHub and we aim to fund further development and maintenance via Patreon. In this post I will explain the issues we faced with commercial licensing and why we think this change will improve the situation and benefit everyone.

A Quick Introduction for Newcomers

Sourcetrail is a cross-platform source explorer that helps you get productive on unfamiliar source code. It uses static analysis on C, C++, Java and Python source code and lets you navigate the collected information within a user interface that interactively combines graph visualization and code display.

This is very cool stuff indeed! I quickly downloaded the portable version and pointed it to a copy of Linux 0.10

I have to say the results look pretty good! Granted it doesn’t like the old archaic assembly macros from a quite bygone era, but this makes exploring the source a joy, as you can not only point to functions, but also see what variables / structs that it’ll touch, and it works backwards letting you quickly see what functions use which structs, adding more viability than say something like src2html.

This is going to be a GREAT tool, no doubt for trying to unwind a bunch of the old software I’ve collected over the years (all on CVS!), although I don’t think it’ll allow for something web based, but such is life.

You can support them on Patreon for as little as $5 for this fantastic software. I know they will get my support at the least.