#simh — Public Fediverse posts

UNIX Fourth Edition on SIMH v3.12-5

UNIX v4 was officially released for the DEC PDP-11/45 computers on November 1973, when those computers were the only computers eligible for this version of UNIX. Since then, it was thought to be lost until November 7th when the tape has been rediscovered. Apparently, this tape was sitting somewhere in one of the storage rooms in the University of Utah.

The Computer History Museum has further handled this by letting bitsavers.org conduct the recovery process, where the tape has been successfully recovered to a raw tape, which has then been uploaded publicly to the Internet Archive for publication, and the installation instructions were then laid out for simh.

So, we have followed the instructions on how to set up a minimal UNIX v4 system on an Arch Linux host using simh version v3.12-5. First, we have downloaded the system tape files.

 [aptivi@archapt ~]$ mkdir uv4  [aptivi@archapt ~]$ cd uv4  [aptivi@archapt uv4]$ wget http://squoze.net/UNIX/v4/disk.rk  --2026-04-01 13:56:49--  http://squoze.net/UNIX/v4/disk.rk  Resolving squoze.net (squoze.net)... 93.128.9.138  Connecting to squoze.net (squoze.net)|93.128.9.138|:80... connected.  HTTP request sent, awaiting response... 200 OK  Length: 2494464 (2.4M) [application/octet-stream]  Saving to: ‘disk.rk’   disk.rk                       100%[================================================>]   2.38M   511KB/s    in 5.8s       2026-04-01 13:56:55 (423 KB/s) - ‘disk.rk’ saved [2494464/2494464]   [aptivi@archapt uv4]$ wget http://squoze.net/UNIX/v4/unix_v4.tap  --2026-04-01 13:57:47--  http://squoze.net/UNIX/v4/unix_v4.tap  Resolving squoze.net (squoze.net)... 93.128.9.138  Connecting to squoze.net (squoze.net)|93.128.9.138|:80... connected.  HTTP request sent, awaiting response... 200 OK  Length: 2572452 (2.5M) [application/octet-stream]  Saving to: ‘unix_v4.tap’   unix_v4.tap                   100%[================================================>]   2.45M   332KB/s    in 6.9s       2026-04-01 13:57:54 (365 KB/s) - ‘unix_v4.tap’ saved [2572452/2572452]   [aptivi@archapt uv4]$ wget http://squoze.net/UNIX/v4/install.ini  --2026-04-01 13:58:00--  http://squoze.net/UNIX/v4/install.ini  Resolving squoze.net (squoze.net)... 93.128.9.138  Connecting to squoze.net (squoze.net)|93.128.9.138|:80... connected.  HTTP request sent, awaiting response... 200 OK  Length: 68 [text/plain]  Saving to: ‘install.ini’   install.ini                   100%[================================================>]      68  --.-KB/s    in 0s         2026-04-01 13:58:00 (10.9 MB/s) - ‘install.ini’ saved [68/68] 

Afterwards, we have installed UNIX v4 files from the installation tape. The install.ini file contained the following contents:

 set cpu 11/45  att rk0 disk.rk  att tm0 unix_v4.tap  d sr 2  boot -o tm 

We had to use the mcopy command to install the system to the rk disk, then use uboot, with writing k and unix to boot to the installed kernel. Depending on your host distribution, the executable file for running the PDP11 simulator is either simh-pdp11 or pdp11.

 [aptivi@archapt uv4]$ simh-pdp11 install.ini   PDP-11 simulator V3.12-5  Disabling XQ  =mcopy  'p' for rp; 'k' for rk  k  disk offset  0  tape offset  75  count  4000  =uboot  k  unix  mem = 64530   login: root  # ls  bin  dev  etc  lib  mnt  tmp  unix  usr  # sync  #   Simulation stopped, PC: 002040 (MOV (SP)+,177776)  sim> exit  Goodbye 

The Unix files have been successfully written to the rk disk, so we need to boot to Unix from it with boot.ini as the configuration file for simh.

Hint: CTRL + D to log out from your user account. CTRL + E to stop the simulation.

 set cpu 11/45  set tc en  att rk0 disk.rk  d sr 2  boot rk 

Again, we have to write both k and unix to boot to the kernel.

 [aptivi@archapt uv4]$ wget http://squoze.net/UNIX/v4/boot.ini  --2026-04-01 13:59:55--  http://squoze.net/UNIX/v4/boot.ini  Resolving squoze.net (squoze.net)... 93.128.9.138  Connecting to squoze.net (squoze.net)|93.128.9.138|:80... connected.  HTTP request sent, awaiting response... 200 OK  Length: 76 [text/plain]  Saving to: ‘boot.ini’   boot.ini                      100%[================================================>]      76  --.-KB/s    in 0s         2026-04-01 13:59:55 (13.3 MB/s) - ‘boot.ini’ saved [76/76]   [aptivi@archapt uv4]$ simh-pdp11 boot.ini   PDP-11 simulator V3.12-5  Disabling XQ  k  unix  mem = 64530   login: root  # 

Now, we need to make device files for tape disk controllers using /etc/mknod and create them on /dev. This is needed to be able to read tapes on the installed system. They will be persistent across reboots.

 # chdir /dev  # /etc/mknod mt0 b 2 0  # /etc/mknod tap0 b 1 0  # /etc/mknod tap1 b 1 1  # /etc/mknod tap2 b 1 2  # /etc/mknod tap3 b 1 3  # sync  #   Simulation stopped, PC: 002040 (MOV (SP)+,177776) 

Now that we have the tape device files, we can now read from tapes. We will recompile the kernel to integrate the enhanced rk driver. After the recompilation, we’ll reboot the system to the new kernel and create device files for rk.

 [aptivi@archapt uv4]$ wget http://squoze.net/UNIX/v4/sys.tp  --2026-04-01 14:02:21--  http://squoze.net/UNIX/v4/sys.tp  Resolving squoze.net (squoze.net)... 93.128.9.138  Connecting to squoze.net (squoze.net)|93.128.9.138|:80... connected.  HTTP request sent, awaiting response... 200 OK  Length: 17408 (17K) [application/octet-stream]  Saving to: ‘sys.tp’   sys.tp                        100%[================================================>]  17.00K  8.45KB/s    in 2.0s       2026-04-01 14:02:25 (8.45 KB/s) - ‘sys.tp’ saved [17408/17408]   [aptivi@archapt uv4]$ simh-pdp11 boot.ini   PDP-11 simulator V3.12-5  Disabling XQ  k  unix  mem = 64530   login: root  #   Simulation stopped, PC: 002040 (MOV (SP)+,177776)  boot.ini> # type k  Unknown command  boot.ini> # type unix  Unknown command  sim> att tc1 sys.tp  TC1: 16b format, buffering file in memory  sim> c   # chdir /usr/sys  # tp 1t  run  dmr/run  dmr/rk.c  ken/run  conf/conf.c     5 entries     9 used   544 free    33 last  END  # chdir /usr/sys/dmr  # mv rk.c rk.c.orig  # chdir ../  # rm -f conf/conf.c  # tp 1x  END  # sh run  alloc.c:  clock.c:  fio.c:  iget.c:  main.c:  nami.c:  prf.c:  rdwri.c:  sig.c:  60: Warning: assignment understood  61: Warning: assignment understood  slp.c:  subr.c:  sys1.c:  sys2.c:  sys3.c:  sys4.c:  sysent.c:  text.c:  trap.c:  bio.c:  cat.c:  dc.c:  dh.c:  dhdm.c:  dhfdm.c:  dn.c:  dp.c:  dv.c:  kl.c:  lp.c:  malloc.c:  mem.c:  partab.c:  pc.c:  pipe.c:  rf.c:  rk.c:  rp.c:  tc.c:  tm.c:  tty.c:  vs.c:  vt.c:  # mv a.out /unix  /unix: 0644 mode y  # sync  #   Simulation stopped, PC: 002040 (MOV (SP)+,177776)  sim> exit  Goodbye  TC1: writing buffer to file  [aptivi@archapt uv4]$ simh-pdp11 boot.ini   PDP-11 simulator V3.12-5  Disabling XQ  k  unix  mem = 64529   login: root  # chdir /dev  # rm -f null  # /etc/mknod mem c 1 0  # /etc/mknod kmem c 1 1  # /etc/mknod null c 1 2  # /etc/mknod rk0 b 0 0  # /etc/mknod rk1 b 0 1  # /etc/mknod rk2 b 0 2  # /etc/mknod rk3 b 0 3  # ls -l  total 0  crw-rw-rw- 1 root    1,  1 Jun 12 19:54 kmem  crw-rw-rw- 1 root    1,  0 Jun 12 19:54 mem  brw-rw-rw- 1 root    2,  0 Jun 12 19:52 mt0  crw-rw-rw- 1 root    1,  2 Jun 12 19:54 null  brw-rw-rw- 1 root    0,  0 Jun 12 19:54 rk0  brw-rw-rw- 1 root    0,  1 Jun 12 19:54 rk1  brw-rw-rw- 1 root    0,  2 Jun 12 19:54 rk2  brw-rw-rw- 1 root    0,  3 Jun 12 19:54 rk3  brw-rw-rw- 1 root    1,  0 Jun 12 19:52 tap0  brw-rw-rw- 1 root    1,  1 Jun 12 19:52 tap1  brw-rw-rw- 1 root    1,  2 Jun 12 19:52 tap2  brw-rw-rw- 1 root    1,  3 Jun 12 19:52 tap3  crw--w--w- 1 root    0,  0 Jun 12 19:55 tty8  # ps a   0     0 ???d??H??`?? ak??Z? ????? k?  ?     0     1 /etc/init     8     7 -     8    17 ps a      0     6 /etc/update    # 

To verify that the new driver works properly, we’ll copy the UNIX source code to the second rk disk. We’ll then make it as a mount point as /usr/source for the source code files that will be located there.

 sim> att tm0 src.tap  TM: creating new file  sim> att rk1 src.rk  RK: creating new file  sim> c   # /etc/mkfs /dev/rk1 4872  isize = 103  # /etc/mount /dev/rk1 /mnt  # chdir /usr/source  # tp mr *   256 entries  1194 used  1256 last  END  # tp mt  s1/ac.c  s1/ar.s  s1/as11.s  s1/as12.s  s1/as13.s  s1/as14.s  s1/as15.s  s1/as16.s  s1/as17.s  s1/as18.s  s1/as19.s  s1/as21.s  s1/as22.s  s1/as23.s  s1/as24.s  s1/as25.s  s1/as26.s  s1/as27.s  s1/as28.s  s1/as29.s  s1/bas0.s  s1/bas1.s  s1/bas2.s  s1/bas3.s  s1/bas4.s  s1/bas5.s  s1/basx.s  s1/cal.c  s1/cat.s  s1/cc.c  s1/cdb.c  s1/check.c  s1/chmod.c  s1/chown.s  s1/clri.s  s1/cmp.s  s1/comm.c  s1/cp.c  s1/date.c  s1/db1.s  s1/db2.s  s1/db3.s  s1/db4.s  s1/dc1.s  s1/dc2.s  s1/dc3.s  s1/dc4.s  s1/dc5.s  s1/dd.c  s1/df.c  s1/diff1.c  s1/diff2.s  s1/dsw.s  s1/du.s  s1/dump.c  s1/echo.c  s1/ed1.s  s1/ed2.s  s1/ed3.s  s1/exit.c  s1/fc.c  s1/fed1.s  s1/fed2.s  s1/fed3.s  s1/find.c  s1/form1.s  s1/form2.s  s1/form3.s  s1/form4.s  s1/form5.s  s1/form6.s  s1/getty.s  s1/glob.c  s1/goto.c  s1/grep.s  s1/if.c  s1/init.c  s1/kill.s  s1/ld1.s  s1/ld2.s  s1/ldx.s  s1/ln.c  s1/login.c  s1/lpd.s  s1/lpr.c  s1/ls.c  s2/mail.c  s2/mesg.s  s2/mkdir.s  s2/mkfs.c  s2/mknod.c  s2/mount.c  s2/msh.s  s2/mv.c  s2/nice.c  s2/nm.c  s2/nohup.c  s2/od.c  s2/passwd.s  s2/pfe.s  s2/pr.c  s2/prof.c  s2/ps.c  s2/pwd.c  s2/restor.c  s2/rew.s  s2/rm.c  s2/rmdir.s  s2/sa.c  s2/sh.c  s2/size.c  s2/sleep.c  s2/sort.c  s2/split.c  s2/strip.s  s2/stty.c  s2/su.c  s2/sum.s  s2/sync.c  s2/tee.c  s2/time.s  s2/tp1.s  s2/tp2.s  s2/tp3.s  s2/tp4.s  s2/tr.c  s2/tty.s  s2/typo.c  s2/umount.c  s2/uniq.c  s2/update.s  s2/wc.c  s2/who.c  s2/write.s  s3/atan.s  s3/atof.s  s3/atoi.s  s3/compar.s  s3/crypt.s  s3/ctime.c  s3/dpadd.s  s3/ecvt.s  s3/exp.s  s3/fakfp.s  s3/fp1.s  s3/fp2.s  s3/fp3.s  s3/fpx.s  s3/gamma.s  s3/get.s  s3/hypot.s  s3/ldiv.s  s3/log.s  s3/mesg.s  s3/mon.s  s3/nlist.s  s3/pow.s  s3/put.s  s3/qsort.s  s3/rand.s  s3/sin.s  s3/sqrt.s  s3/switch.s  s3/ttyn.s  s4/abort.s  s4/atan.s  s4/atan2.s  s4/atof.s  s4/chdir.s  s4/chmod.s  s4/chown.s  s4/close.s  s4/cos.s  s4/crand.s  s4/creat.s  s4/crt0.s  s4/crypt.s  s4/dup.s  s4/ecvt.s  s4/errlst.c  s4/execl.s  s4/execv.s  s4/exit.s  s4/exp.s  s4/ffltpr.s  s4/floor.s  s4/fltpr.s  s4/fmod.s  s4/fork.s  s4/fstat.s  s4/gamma.s  s4/getc.s  s4/getchr.s  s4/getcsw.s  s4/getgid.s  s4/getpw.c  s4/getuid.s  s4/gtty.s  s4/hmul.s  s4/hsw.s  s4/kill.s  s4/link.s  s4/locv.s  s4/log.s  s4/ltod.s  s4/makdir.s  s4/mcrt0.s  s4/mdate.s  s4/mknod.s  s4/mon.c  s4/mount.s  s4/nargs.s  s4/nice.s  s4/nlist.s  s4/open.s  s4/perror.c  s4/pipe.s  s4/pow.s  s4/printf.s  s4/prof.s  s4/putc.s  s4/putchr.s  s4/qsort.c  s4/read.s  s4/reset.s  s4/retrn.s  s4/rin.c  s4/rsave.s  s4/sbrk.s  s4/seek.s  s4/setgid.s  s4/setuid.s  s4/signal.s  s4/sin.s  s4/sleep.s  s4/sqrt.s  s4/ssw.s  s4/stat.s  s4/stime.s  s4/stty.s  s4/switch.s  s4/sync.s  s4/time.s  s4/times.s  s4/umount.s  s4/unlink.s  s4/wait.s  s4/write.s  s7/roff1.s  s7/roff2.s  s7/roff3.s  s7/roff4.s  s7/roff5.s  s7/roff7.s  s7/roff8.s  s7/suftab.s   256 entries  1194 used  1256 last  END  # chdir /mnt  # mkdir s1 s2 s3 s4 s7  # chown bin *  # chmod 755 *  # tp mx  END  # chdir /usr/source/s1  # rm -f [a-f]*  # rm -f *  # chdir ../s2  # rm -f *  # chdir ../s3  # rm -f *  # chdir ../s4  # rm -f [a-f]*  # rm -f *  # chdir ../s7  # rm -f *  # chdir ..  # rmdir *  # chdir /  # /etc/umount /dev/rk1  # /etc/mount /dev/rk1 /usr/source  # ed /etc/rc  70  $  /etc/update  i  /etc/mount /dev/rk1 /usr/source  .  w  102  q  #  

Adding users to this system isn’t as straightforward as the modern Unix distributions; you’ll need to directly modify the /etc/passwd file to add a new entry that contains a new user, aptivi.

 # ed /etc/passwd  30  $  bin::3:1::/bin:  a  aptivi::10:1::/usr/aptivi:  .  w  57  q  # mkdir /usr/aptivi  # chown aptivi /usr/aptivi  #   login: aptivi  % who  aptivi  tty8 Jun 12 20:03  %   login: root  # passwd aptivi test  #   login: aptivi  Password:   % 

As the site that provided us this tutorial claimed that we can install the B programming language compiler, but our tests have failed due to errors in the installation process.

 [aptivi@archapt uv4]$ wget http://squoze.net/B/b.tp  --2026-04-01 14:15:13--  http://squoze.net/B/b.tp  Resolving squoze.net (squoze.net)... 93.128.9.138  Connecting to squoze.net (squoze.net)|93.128.9.138|:80... connected.  HTTP request sent, awaiting response... 200 OK  Length: 137216 (134K) [application/octet-stream]  Saving to: ‘b.tp’   b.tp                          100%[================================================>] 134.00K   168KB/s    in 0.8s       2026-04-01 14:15:14 (168 KB/s) - ‘b.tp’ saved [137216/137216]   [aptivi@archapt uv4]$ simh-pdp11 boot.ini   PDP-11 simulator V3.12-5  Disabling XQ  k  unix  mem = 64529   login: root  #   Simulation stopped, PC: 002040 (MOV (SP)+,177776)  boot.ini> # type k  Unknown command  boot.ini> # type unix  Unknown command  sim> at tc0 b.tp  TC0: 16b format, buffering file in memory  sim> c   # mkdir /usr/b  # chdir /usr/b  # mkdir bilib libb  # chown bin *  # chmod 755 *  # tp 0x  END  # sh install  libb.a: non existent  chdir  chmod  chown  close  creat  ctime  execl  execv  exit  fork  fstat  getchr  getuid  gtty  lchar  link  makdir  open  printf  printn  putchr  read  seek  setuid  sleep  stat  stty  time  unlink  wait  write  char  bilib.a: non existent  a  b1  b10  b102  b103  b11  b112  b113  b114  b115  b116  b117  b12  b120  b13  b14  b15  b16  b17  b2  b20  b3  b4  b5  b6  b7  c  f  n11  n123  n4  n6  n7  s  t  u10  u2  u3  u4  u5  u6  u7  va  vx  x  y  z  brt1  brt2  bc  File not found: /usr/lib/bilib.a  un: s  un: x  un: c  un: n4  un: b7  un: f  un: ix  un: n2  un: vx  un: t  un: n3  un: ivx  un: b1  un: u4  un: n1  un: b5  un: n11  un: va  un: iva  un: u10  un: u7  un: a  un: ia  un: b4  un: b14  un: b2  un: n6  un: z  un: b11  un: b114  un: u3  un: b3  un: b10  un: b15  un: b17  un: u5  un: y  un: u2  un: u6  un: b6  un: b116  un: b117  un: n7  un: ic  un: b103  un: b13  un: b20  un: b16  ba  File not found: /usr/lib/bilib.a  un: y  un: s  un: x  un: c  un: n4  un: b7  un: f  un: ix  un: n2  un: vx  un: t  un: n3  un: ivx  un: b1  un: iva  un: n1  un: b11  un: ia  un: z  un: n6  un: a  un: b17  un: b14  un: va  un: b114  un: u7  un: b5  un: b4  un: b15  un: u6  un: u3  un: n11  un: b3  un: u10  un: b10  un: b2  un: u2  un: n7  un: ic  un: b20  un: b16  B  i  Bus error -- Core dumped  Source file non-existent  B  i  Bus error -- Core dumped  Source file non-existent  #  

Other than this error when it comes to the B programming language, the Unix system works.

I am happy with this DECSystem-10 MUD system for now; it's been a 35-year task.

If anyone is bored enough to be curious!

31 January 1991: Essex University's DECSystem-10 closes, meaning that MIST and ROCK, and the dodgy version of MUD we had on there, had to close. I had a mostly working VMS system that would run it with some extra programming, but I'd already sent out AberMUD to Vijay, and he'd sent it out to the world, and TinyMUDs were becoming common. MIST was losing its captive audience, and it needed that level of addiction and co-dependence to run, so I decided to let it die in its prime, rather than become a sad old relic that nobody played.

2003 and the next 20 years: I decided to build a TOPS-10 system on a VMS machine and install MIST/MUD and ROCK. Got quite a long way, and then discovered there was no BCPL compiler existing anywhere in the known world. A few years later, Richard Bartle told me that Paul Allen (I think) had found one. So this became possible, and Quentin (dot-co-dot-uk) took a great stab at it with some really old code, and Viktor Toth had BL running, so I figured that was enough. Sometime in this period, Bletchley Park got something that looked like a PDP-10, and they suggested that I go and put MUD onto it for the museum. It wasn't a PDP-10, but I did look into putting it onto a VAX for a while, but the management of Bletchley, as it turned into The National Museum of Computing (TNMOC), was getting more corporate and boring, so I gave up bothering.

19th Feb to 22nd Feb, 2026: I decided to build a PRIMOS machine on a Simh emulator for no apparent reason. It went fairly smoothly, so I wondered again about a DEC-10. I was missing TOPS-10 anyway, so why not? Proof of concept, setting up some test systems, seeing where TOPS-10 emulators were at these days and seeing how far Quentin had really got and how much extra work was needed. Realised I am going to have to start from scratch, mostly, using a prebuilt Steuben distro of TOPS-10 7.03 as the base.

Took a couple of weeks off to ponder whether the rest was worth it, but decided my $200 a month ChatGPT Pro subscription may as well pay for itself with background research, so I decided to go ahead.

9th March 9 to 18th March, 2026: A long sprint, and I mostly got it all working. 92 hours of concentrated swearing and about 15 hours of destroying the planet with GPT Deep Research mode later (*), after at least 2 false starts and complete wipes. I got a system I am relatively happy with. Somewhere in there is about 4 hours of relearning TECO and fighting with getting ROCK working on code it was never meant to work on. There's still more to do, but that's just maintenance now.

BUT I FOUND ROCK! I thought it was lost forever. Somehow, that's my major victory in all this. Building the setup was hard, tedious, and very frustrating work. It probably did need somebody who knew a lot about both DEC and Unix systems management, and the MUD engine, to guide it, but it was still mostly a matter of putting together things that already existed and forcing them to work together. ROCK, though, I genuinely thought was 100% lost.

It's taken a hundred plus concentrated hours, two new dedicated hosts, a small town's water supply, and probably a few megawatts of power in the background. But this is the final re-creation of the systems I closed at the start of the 1990s.

MIST (and MUD and ROCK) will still probably end up as relics that nobody properly plays, but this project is not pretending to be anything other than an interesting throwback and museum piece now, which, 35 years after I closed it down, seems a fitting end. It also means I can resurrect Duncan Rogerson's arch-wizard, and that seems right, somehow. I will leave it up and running now.

(*) Since someone whined about my use of GPT - I could not have mentioned it, but I did because, for some tasks like this one, it saved me hundreds of hours and a lot of Googling. If I have to pick (which I do!) I'd rather use GPT than Google still. One of the useful things you can do with Deep Research is to give it a topic you want to aggregate information on (like ACCESS.USR usage) and send it away to make a summary PDF of the key points of what's useful, but triple-checked and sourced. I have read the Original TOPS-10 manuals that are wonderfully hosted on @bitsavers many times, I could knock up a perfect ACCESS.USR in a drunken stupor, whilst half asleep once, but these days I barely remember the 3-part octal protections, so I am happy to have a reference I don't need to read 10 parts of 3 different manuals to make. That's why I use AI, and I am perfectly comfortable with that. Since I work in AI Ethics and actually put into practice what I preach, I am comfortable with my use of AI, and I always disclose it :P

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security #TNMOC #blog #ADHD #Autism

I am happy with this DECSystem-10 MUD system for now; it's been a 35-year task.

If anyone is bored enough to be curious!

31 January 1991: Essex University's DECSystem-10 closes, meaning that MIST and ROCK, and the dodgy version of MUD we had on there, had to close. I had a mostly working VMS system that would run it with some extra programming, but I'd already sent out AberMUD to Vijay, and he'd sent it out to the world, and TinyMUDs were becoming common. MIST was losing its captive audience, and it needed that level of addiction and co-dependence to run, so I decided to let it die in its prime, rather than become a sad old relic that nobody played.

2003 and the next 20 years: I decided to build a TOPS-10 system on a VMS machine and install MIST/MUD and ROCK. Got quite a long way, and then discovered there was no BCPL compiler existing anywhere in the known world. A few years later, Richard Bartle told me that Paul Allen (I think) had found one. So this became possible, and Quentin (dot-co-dot-uk) took a great stab at it with some really old code, and Viktor Toth had BL running, so I figured that was enough. Sometime in this period, Bletchley Park got something that looked like a PDP-10, and they suggested that I go and put MUD onto it for the museum. It wasn't a PDP-10, but I did look into putting it onto a VAX for a while, but the management of Bletchley, as it turned into The National Museum of Computing (TNMOC), was getting more corporate and boring, so I gave up bothering.

19th Feb to 22nd Feb, 2026: I decided to build a PRIMOS machine on a Simh emulator for no apparent reason. It went fairly smoothly, so I wondered again about a DEC-10. I was missing TOPS-10 anyway, so why not? Proof of concept, setting up some test systems, seeing where TOPS-10 emulators were at these days and seeing how far Quentin had really got and how much extra work was needed. Realised I am going to have to start from scratch, mostly, using a prebuilt Steuben distro of TOPS-10 7.03 as the base.

Took a couple of weeks off to ponder whether the rest was worth it, but decided my $200 a month ChatGPT Pro subscription may as well pay for itself with background research, so I decided to go ahead.

9th March 9 to 18th March, 2026: A long sprint, and I mostly got it all working. 92 hours of concentrated swearing and about 15 hours of destroying the planet with GPT Deep Research mode later (*), after at least 2 false starts and complete wipes. I got a system I am relatively happy with. Somewhere in there is about 4 hours of relearning TECO and fighting with getting ROCK working on code it was never meant to work on. There's still more to do, but that's just maintenance now.

BUT I FOUND ROCK! I thought it was lost forever. Somehow, that's my major victory in all this. Building the setup was hard, tedious, and very frustrating work. It probably did need somebody who knew a lot about both DEC and Unix systems management, and the MUD engine, to guide it, but it was still mostly a matter of putting together things that already existed and forcing them to work together. ROCK, though, I genuinely thought was 100% lost.

It's taken a hundred plus concentrated hours, two new dedicated hosts, a small town's water supply, and probably a few megawatts of power in the background. But this is the final re-creation of the systems I closed at the start of the 1990s.

MIST (and MUD and ROCK) will still probably end up as relics that nobody properly plays, but this project is not pretending to be anything other than an interesting throwback and museum piece now, which, 35 years after I closed it down, seems a fitting end. It also means I can resurrect Duncan Rogerson's arch-wizard, and that seems right, somehow. I will leave it up and running now.

(*) Since someone whined about my use of GPT - I could not have mentioned it, but I did because, for some tasks like this one, it saved me hundreds of hours and a lot of Googling. If I have to pick (which I do!) I'd rather use GPT than Google still. One of the useful things you can do with Deep Research is to give it a topic you want to aggregate information on (like ACCESS.USR usage) and send it away to make a summary PDF of the key points of what's useful, but triple-checked and sourced. I have read the Original TOPS-10 manuals that are wonderfully hosted on @bitsavers many times, I could knock up a perfect ACCESS.USR in a drunken stupor, whilst half asleep once, but these days I barely remember the 3-part octal protections, so I am happy to have a reference I don't need to read 10 parts of 3 different manuals to make. That's why I use AI, and I am perfectly comfortable with that. Since I work in AI Ethics and actually put into practice what I preach, I am comfortable with my use of AI, and I always disclose it :P

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security #TNMOC #blog #ADHD #Autism

I am happy with this DECSystem-10 MUD system for now; it's been a 35-year task.

If anyone is bored enough to be curious!

31 January 1991: Essex University's DECSystem-10 closes, meaning that MIST and ROCK, and the dodgy version of MUD we had on there, had to close. I had a mostly working VMS system that would run it with some extra programming, but I'd already sent out AberMUD to Vijay, and he'd sent it out to the world, and TinyMUDs were becoming common. MIST was losing its captive audience, and it needed that level of addiction and co-dependence to run, so I decided to let it die in its prime, rather than become a sad old relic that nobody played.

2003 and the next 20 years: I decided to build a TOPS-10 system on a VMS machine and install MIST/MUD and ROCK. Got quite a long way, and then discovered there was no BCPL compiler existing anywhere in the known world. A few years later, Richard Bartle told me that Paul Allen (I think) had found one. So this became possible, and Quentin (dot-co-dot-uk) took a great stab at it with some really old code, and Viktor Toth had BL running, so I figured that was enough. Sometime in this period, Bletchley Park got something that looked like a PDP-10, and they suggested that I go and put MUD onto it for the museum. It wasn't a PDP-10, but I did look into putting it onto a VAX for a while, but the management of Bletchley, as it turned into The National Museum of Computing (TNMOC), was getting more corporate and boring, so I gave up bothering.

19th Feb to 22nd Feb, 2026: I decided to build a PRIMOS machine on a Simh emulator for no apparent reason. It went fairly smoothly, so I wondered again about a DEC-10. I was missing TOPS-10 anyway, so why not? Proof of concept, setting up some test systems, seeing where TOPS-10 emulators were at these days and seeing how far Quentin had really got and how much extra work was needed. Realised I am going to have to start from scratch, mostly, using a prebuilt Steuben distro of TOPS-10 7.03 as the base.

Took a couple of weeks off to ponder whether the rest was worth it, but decided my $200 a month ChatGPT Pro subscription may as well pay for itself with background research, so I decided to go ahead.

9th March 9 to 18th March, 2026: A long sprint, and I mostly got it all working. 92 hours of concentrated swearing and about 15 hours of destroying the planet with GPT Deep Research mode later (*), after at least 2 false starts and complete wipes. I got a system I am relatively happy with. Somewhere in there is about 4 hours of relearning TECO and fighting with getting ROCK working on code it was never meant to work on. There's still more to do, but that's just maintenance now.

BUT I FOUND ROCK! I thought it was lost forever. Somehow, that's my major victory in all this. Building the setup was hard, tedious, and very frustrating work. It probably did need somebody who knew a lot about both DEC and Unix systems management, and the MUD engine, to guide it, but it was still mostly a matter of putting together things that already existed and forcing them to work together. ROCK, though, I genuinely thought was 100% lost.

It's taken a hundred plus concentrated hours, two new dedicated hosts, a small town's water supply, and probably a few megawatts of power in the background. But this is the final re-creation of the systems I closed at the start of the 1990s.

MIST (and MUD and ROCK) will still probably end up as relics that nobody properly plays, but this project is not pretending to be anything other than an interesting throwback and museum piece now, which, 35 years after I closed it down, seems a fitting end. It also means I can resurrect Duncan Rogerson's arch-wizard, and that seems right, somehow. I will leave it up and running now.

(*) Since someone whined about my use of GPT - I could not have mentioned it, but I did because, for some tasks like this one, it saved me hundreds of hours and a lot of Googling. If I have to pick (which I do!) I'd rather use GPT than Google still. One of the useful things you can do with Deep Research is to give it a topic you want to aggregate information on (like ACCESS.USR usage) and send it away to make a summary PDF of the key points of what's useful, but triple-checked and sourced. I have read the Original TOPS-10 manuals that are wonderfully hosted on @bitsavers many times, I could knock up a perfect ACCESS.USR in a drunken stupor, whilst half asleep once, but these days I barely remember the 3-part octal protections, so I am happy to have a reference I don't need to read 10 parts of 3 different manuals to make. That's why I use AI, and I am perfectly comfortable with that. Since I work in AI Ethics and actually put into practice what I preach, I am comfortable with my use of AI, and I always disclose it :P

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security #TNMOC #blog #ADHD #Autism

I am happy with this DECSystem-10 MUD system for now; it's been a 35-year task.

If anyone is bored enough to be curious!

31 January 1991: Essex University's DECSystem-10 closes, meaning that MIST and ROCK, and the dodgy version of MUD we had on there, had to close. I had a mostly working VMS system that would run it with some extra programming, but I'd already sent out AberMUD to Vijay, and he'd sent it out to the world, and TinyMUDs were becoming common. MIST was losing its captive audience, and it needed that level of addiction and co-dependence to run, so I decided to let it die in its prime, rather than become a sad old relic that nobody played.

2003 and the next 20 years: I decided to build a TOPS-10 system on a VMS machine and install MIST/MUD and ROCK. Got quite a long way, and then discovered there was no BCPL compiler existing anywhere in the known world. A few years later, Richard Bartle told me that Paul Allen (I think) had found one. So this became possible, and Quentin (dot-co-dot-uk) took a great stab at it with some really old code, and Viktor Toth had BL running, so I figured that was enough. Sometime in this period, Bletchley Park got something that looked like a PDP-10, and they suggested that I go and put MUD onto it for the museum. It wasn't a PDP-10, but I did look into putting it onto a VAX for a while, but the management of Bletchley, as it turned into The National Museum of Computing (TNMOC), was getting more corporate and boring, so I gave up bothering.

19th Feb to 22nd Feb, 2026: I decided to build a PRIMOS machine on a Simh emulator for no apparent reason. It went fairly smoothly, so I wondered again about a DEC-10. I was missing TOPS-10 anyway, so why not? Proof of concept, setting up some test systems, seeing where TOPS-10 emulators were at these days and seeing how far Quentin had really got and how much extra work was needed. Realised I am going to have to start from scratch, mostly, using a prebuilt Steuben distro of TOPS-10 7.03 as the base.

Took a couple of weeks off to ponder whether the rest was worth it, but decided my $200 a month ChatGPT Pro subscription may as well pay for itself with background research, so I decided to go ahead.

9th March 9 to 18th March, 2026: A long sprint, and I mostly got it all working. 92 hours of concentrated swearing and about 15 hours of destroying the planet with GPT Deep Research mode later (*), after at least 2 false starts and complete wipes. I got a system I am relatively happy with. Somewhere in there is about 4 hours of relearning TECO and fighting with getting ROCK working on code it was never meant to work on. There's still more to do, but that's just maintenance now.

BUT I FOUND ROCK! I thought it was lost forever. Somehow, that's my major victory in all this. Building the setup was hard, tedious, and very frustrating work. It probably did need somebody who knew a lot about both DEC and Unix systems management, and the MUD engine, to guide it, but it was still mostly a matter of putting together things that already existed and forcing them to work together. ROCK, though, I genuinely thought was 100% lost.

It's taken a hundred plus concentrated hours, two new dedicated hosts, a small town's water supply, and probably a few megawatts of power in the background. But this is the final re-creation of the systems I closed at the start of the 1990s.

MIST (and MUD and ROCK) will still probably end up as relics that nobody properly plays, but this project is not pretending to be anything other than an interesting throwback and museum piece now, which, 35 years after I closed it down, seems a fitting end. It also means I can resurrect Duncan Rogerson's arch-wizard, and that seems right, somehow. I will leave it up and running now.

(*) Since someone whined about my use of GPT - I could not have mentioned it, but I did because, for some tasks like this one, it saved me hundreds of hours and a lot of Googling. If I have to pick (which I do!) I'd rather use GPT than Google still. One of the useful things you can do with Deep Research is to give it a topic you want to aggregate information on (like ACCESS.USR usage) and send it away to make a summary PDF of the key points of what's useful, but triple-checked and sourced. I have read the Original TOPS-10 manuals that are wonderfully hosted on @bitsavers many times, I could knock up a perfect ACCESS.USR in a drunken stupor, whilst half asleep once, but these days I barely remember the 3-part octal protections, so I am happy to have a reference I don't need to read 10 parts of 3 different manuals to make. That's why I use AI, and I am perfectly comfortable with that. Since I work in AI Ethics and actually put into practice what I preach, I am comfortable with my use of AI, and I always disclose it :P

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security #TNMOC #blog #ADHD #Autism

I am happy with this DECSystem-10 MUD system for now; it's been a 35-year task.

If anyone is bored enough to be curious!

31 January 1991: Essex University's DECSystem-10 closes, meaning that MIST and ROCK, and the dodgy version of MUD we had on there, had to close. I had a mostly working VMS system that would run it with some extra programming, but I'd already sent out AberMUD to Vijay, and he'd sent it out to the world, and TinyMUDs were becoming common. MIST was losing its captive audience, and it needed that level of addiction and co-dependence to run, so I decided to let it die in its prime, rather than become a sad old relic that nobody played.

2003 and the next 20 years: I decided to build a TOPS-10 system on a VMS machine and install MIST/MUD and ROCK. Got quite a long way, and then discovered there was no BCPL compiler existing anywhere in the known world. A few years later, Richard Bartle told me that Paul Allen (I think) had found one. So this became possible, and Quentin (dot-co-dot-uk) took a great stab at it with some really old code, and Viktor Toth had BL running, so I figured that was enough. Sometime in this period, Bletchley Park got something that looked like a PDP-10, and they suggested that I go and put MUD onto it for the museum. It wasn't a PDP-10, but I did look into putting it onto a VAX for a while, but the management of Bletchley, as it turned into The National Museum of Computing (TNMOC), was getting more corporate and boring, so I gave up bothering.

19th Feb to 22nd Feb, 2026: I decided to build a PRIMOS machine on a Simh emulator for no apparent reason. It went fairly smoothly, so I wondered again about a DEC-10. I was missing TOPS-10 anyway, so why not? Proof of concept, setting up some test systems, seeing where TOPS-10 emulators were at these days and seeing how far Quentin had really got and how much extra work was needed. Realised I am going to have to start from scratch, mostly, using a prebuilt Steuben distro of TOPS-10 7.03 as the base.

Took a couple of weeks off to ponder whether the rest was worth it, but decided my $200 a month ChatGPT Pro subscription may as well pay for itself with background research, so I decided to go ahead.

9th March 9 to 18th March, 2026: A long sprint, and I mostly got it all working. 92 hours of concentrated swearing and about 15 hours of destroying the planet with GPT Deep Research mode later (*), after at least 2 false starts and complete wipes. I got a system I am relatively happy with. Somewhere in there is about 4 hours of relearning TECO and fighting with getting ROCK working on code it was never meant to work on. There's still more to do, but that's just maintenance now.

BUT I FOUND ROCK! I thought it was lost forever. Somehow, that's my major victory in all this. Building the setup was hard, tedious, and very frustrating work. It probably did need somebody who knew a lot about both DEC and Unix systems management, and the MUD engine, to guide it, but it was still mostly a matter of putting together things that already existed and forcing them to work together. ROCK, though, I genuinely thought was 100% lost.

It's taken a hundred plus concentrated hours, two new dedicated hosts, a small town's water supply, and probably a few megawatts of power in the background. But this is the final re-creation of the systems I closed at the start of the 1990s.

MIST (and MUD and ROCK) will still probably end up as relics that nobody properly plays, but this project is not pretending to be anything other than an interesting throwback and museum piece now, which, 35 years after I closed it down, seems a fitting end. It also means I can resurrect Duncan Rogerson's arch-wizard, and that seems right, somehow. I will leave it up and running now.

(*) Since someone whined about my use of GPT - I could not have mentioned it, but I did because, for some tasks like this one, it saved me hundreds of hours and a lot of Googling. If I have to pick (which I do!) I'd rather use GPT than Google still. One of the useful things you can do with Deep Research is to give it a topic you want to aggregate information on (like ACCESS.USR usage) and send it away to make a summary PDF of the key points of what's useful, but triple-checked and sourced. I have read the Original TOPS-10 manuals that are wonderfully hosted on @bitsavers many times, I could knock up a perfect ACCESS.USR in a drunken stupor, whilst half asleep once, but these days I barely remember the 3-part octal protections, so I am happy to have a reference I don't need to read 10 parts of 3 different manuals to make. That's why I use AI, and I am perfectly comfortable with that. Since I work in AI Ethics and actually put into practice what I preach, I am comfortable with my use of AI, and I always disclose it :P

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security #TNMOC #blog #ADHD #Autism

This one might be interesting to anyone interested in computer gaming history.

https://dec10.uknet.net

I spent the last couple of weeks finally finishing a project I started for Bletchley Park about 20 years ago. Recreating the original MUD and MIST on a mirror of the original Essex University system that finally closed in 1991.

Roy Trubshaw and Richard Bartle wrote the first online multi-user game (MUD) on Essex University's DECSystem-10 in 1978 and it ran till I closed it in 1991. I diligently backed everything up so I could potentially recover it one day, but as far as I can see, all the DECSystem-10's went to the great scrapyard in the sky, my backups were mostly stolen when my first museum was stolen, and I had huge issues recovering the Essex BCPL compiler to compile what I had left when I finally got a decent TOPS-10 emulator running on a VAX for Bletchley Park.

One good thing about being an unemployable whistleblower is free time, so I finally hunkered down to some 90 hour weeks and built a software replica of the Essex system I think reflects it well. It's running on a KS10 not a KL10 but I had to let some things slip.

I put the latest known versions of MUD and MIST on it, and miraculously found ROCK too.

So, to meander to the point, if you want to see and relive exactly what online multi user gaming was like from 1978 to 1991, you can go to:

https://dec10.uknet.net

Or:

telnet telnet.dec10.uknet.net

(Port 2653 is available for ISPs that block 23)

And then follow the terse instructions from there.

In those days, you were generally faced with a "." prompt and left mostly alone, so for authenticity, I will leave it at that.

I should note that although they were, in their day, wildly popular games with a relatively huge community, this is a museum peice in snapshot-form at the moment. But I will leave them up and running to see what happens and as a useful reference. I wasn't going to, but Richard seemed happy to have MUD running, and former MIST players wanted it back, so...

Pop this a share if you know folks who might be interested.

** Update: New web client that works better.

** Another update - I added a telnet client.

Historically, the telnet connection is much more true to the traditional experience, where you were connecting to a working machine that didn't care about the MUD Guests, so there were no pointers at all. Just rumour and hearsay :)

If any of you Unix/Security people notice I messed up something, please tell me. I left "^], !sh" open on the telnet link for about 2 minutes and nearly had a heart-attack once I spotted it :D

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security

(don't try this on a phone!)

This one might be interesting to anyone interested in computer gaming history.

https://dec10.uknet.net

I spent the last couple of weeks finally finishing a project I started for Bletchley Park about 20 years ago. Recreating the original MUD and MIST on a mirror of the original Essex University system that finally closed in 1991.

Roy Trubshaw and Richard Bartle wrote the first online multi-user game (MUD) on Essex University's DECSystem-10 in 1978 and it ran till I closed it in 1991. I diligently backed everything up so I could potentially recover it one day, but as far as I can see, all the DECSystem-10's went to the great scrapyard in the sky, my backups were mostly stolen when my first museum was stolen, and I had huge issues recovering the Essex BCPL compiler to compile what I had left when I finally got a decent TOPS-10 emulator running on a VAX for Bletchley Park.

One good thing about being an unemployable whistleblower is free time, so I finally hunkered down to some 90 hour weeks and built a software replica of the Essex system I think reflects it well. It's running on a KS10 not a KL10 but I had to let some things slip.

I put the latest known versions of MUD and MIST on it, and miraculously found ROCK too.

So, to meander to the point, if you want to see and relive exactly what online multi user gaming was like from 1978 to 1991, you can go to:

https://dec10.uknet.net

Or:

telnet telnet.dec10.uknet.net

(Port 2653 is available for ISPs that block 23)

And then follow the terse instructions from there.

In those days, you were generally faced with a "." prompt and left mostly alone, so for authenticity, I will leave it at that.

I should note that although they were, in their day, wildly popular games with a relatively huge community, this is a museum peice in snapshot-form at the moment. But I will leave them up and running to see what happens and as a useful reference. I wasn't going to, but Richard seemed happy to have MUD running, and former MIST players wanted it back, so...

Pop this a share if you know folks who might be interested.

** Update: New web client that works better.

** Another update - I added a telnet client.

Historically, the telnet connection is much more true to the traditional experience, where you were connecting to a working machine that didn't care about the MUD Guests, so there were no pointers at all. Just rumour and hearsay :)

If any of you Unix/Security people notice I messed up something, please tell me. I left "^], !sh" open on the telnet link for about 2 minutes and nearly had a heart-attack once I spotted it :D

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security

(don't try this on a phone!)

This one might be interesting to anyone interested in computer gaming history.

https://dec10.uknet.net

I spent the last couple of weeks finally finishing a project I started for Bletchley Park about 20 years ago. Recreating the original MUD and MIST on a mirror of the original Essex University system that finally closed in 1991.

Roy Trubshaw and Richard Bartle wrote the first online multi-user game (MUD) on Essex University's DECSystem-10 in 1978 and it ran till I closed it in 1991. I diligently backed everything up so I could potentially recover it one day, but as far as I can see, all the DECSystem-10's went to the great scrapyard in the sky, my backups were mostly stolen when my first museum was stolen, and I had huge issues recovering the Essex BCPL compiler to compile what I had left when I finally got a decent TOPS-10 emulator running on a VAX for Bletchley Park.

One good thing about being an unemployable whistleblower is free time, so I finally hunkered down to some 90 hour weeks and built a software replica of the Essex system I think reflects it well. It's running on a KS10 not a KL10 but I had to let some things slip.

I put the latest known versions of MUD and MIST on it, and miraculously found ROCK too.

So, to meander to the point, if you want to see and relive exactly what online multi user gaming was like from 1978 to 1991, you can go to:

https://dec10.uknet.net

Or:

telnet telnet.dec10.uknet.net

(Port 2653 is available for ISPs that block 23)

And then follow the terse instructions from there.

In those days, you were generally faced with a "." prompt and left mostly alone, so for authenticity, I will leave it at that.

I should note that although they were, in their day, wildly popular games with a relatively huge community, this is a museum peice in snapshot-form at the moment. But I will leave them up and running to see what happens and as a useful reference. I wasn't going to, but Richard seemed happy to have MUD running, and former MIST players wanted it back, so...

Pop this a share if you know folks who might be interested.

** Update: New web client that works better.

** Another update - I added a telnet client.

Historically, the telnet connection is much more true to the traditional experience, where you were connecting to a working machine that didn't care about the MUD Guests, so there were no pointers at all. Just rumour and hearsay :)

If any of you Unix/Security people notice I messed up something, please tell me. I left "^], !sh" open on the telnet link for about 2 minutes and nearly had a heart-attack once I spotted it :D

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security

(don't try this on a phone!)

This one might be interesting to anyone interested in computer gaming history.

https://dec10.uknet.net

I spent the last couple of weeks finally finishing a project I started for Bletchley Park about 20 years ago. Recreating the original MUD and MIST on a mirror of the original Essex University system that finally closed in 1991.

Roy Trubshaw and Richard Bartle wrote the first online multi-user game (MUD) on Essex University's DECSystem-10 in 1978 and it ran till I closed it in 1991. I diligently backed everything up so I could potentially recover it one day, but as far as I can see, all the DECSystem-10's went to the great scrapyard in the sky, my backups were mostly stolen when my first museum was stolen, and I had huge issues recovering the Essex BCPL compiler to compile what I had left when I finally got a decent TOPS-10 emulator running on a VAX for Bletchley Park.

One good thing about being an unemployable whistleblower is free time, so I finally hunkered down to some 90 hour weeks and built a software replica of the Essex system I think reflects it well. It's running on a KS10 not a KL10 but I had to let some things slip.

I put the latest known versions of MUD and MIST on it, and miraculously found ROCK too.

So, to meander to the point, if you want to see and relive exactly what online multi user gaming was like from 1978 to 1991, you can go to:

https://dec10.uknet.net

Or:

telnet telnet.dec10.uknet.net

(Port 2653 is available for ISPs that block 23)

And then follow the terse instructions from there.

In those days, you were generally faced with a "." prompt and left mostly alone, so for authenticity, I will leave it at that.

I should note that although they were, in their day, wildly popular games with a relatively huge community, this is a museum peice in snapshot-form at the moment. But I will leave them up and running to see what happens and as a useful reference. I wasn't going to, but Richard seemed happy to have MUD running, and former MIST players wanted it back, so...

Pop this a share if you know folks who might be interested.

** Update: New web client that works better.

** Another update - I added a telnet client.

Historically, the telnet connection is much more true to the traditional experience, where you were connecting to a working machine that didn't care about the MUD Guests, so there were no pointers at all. Just rumour and hearsay :)

If any of you Unix/Security people notice I messed up something, please tell me. I left "^], !sh" open on the telnet link for about 2 minutes and nearly had a heart-attack once I spotted it :D

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security

(don't try this on a phone!)

This one might be interesting to anyone interested in computer gaming history.

https://dec10.uknet.net

I spent the last couple of weeks finally finishing a project I started for Bletchley Park about 20 years ago. Recreating the original MUD and MIST on a mirror of the original Essex University system that finally closed in 1991.

Roy Trubshaw and Richard Bartle wrote the first online multi-user game (MUD) on Essex University's DECSystem-10 in 1978 and it ran till I closed it in 1991. I diligently backed everything up so I could potentially recover it one day, but as far as I can see, all the DECSystem-10's went to the great scrapyard in the sky, my backups were mostly stolen when my first museum was stolen, and I had huge issues recovering the Essex BCPL compiler to compile what I had left when I finally got a decent TOPS-10 emulator running on a VAX for Bletchley Park.

One good thing about being an unemployable whistleblower is free time, so I finally hunkered down to some 90 hour weeks and built a software replica of the Essex system I think reflects it well. It's running on a KS10 not a KL10 but I had to let some things slip.

I put the latest known versions of MUD and MIST on it, and miraculously found ROCK too.

So, to meander to the point, if you want to see and relive exactly what online multi user gaming was like from 1978 to 1991, you can go to:

https://dec10.uknet.net

Or:

telnet telnet.dec10.uknet.net

(Port 2653 is available for ISPs that block 23)

And then follow the terse instructions from there.

In those days, you were generally faced with a "." prompt and left mostly alone, so for authenticity, I will leave it at that.

I should note that although they were, in their day, wildly popular games with a relatively huge community, this is a museum peice in snapshot-form at the moment. But I will leave them up and running to see what happens and as a useful reference. I wasn't going to, but Richard seemed happy to have MUD running, and former MIST players wanted it back, so...

Pop this a share if you know folks who might be interested.

** Update: New web client that works better.

** Another update - I added a telnet client.

Historically, the telnet connection is much more true to the traditional experience, where you were connecting to a working machine that didn't care about the MUD Guests, so there were no pointers at all. Just rumour and hearsay :)

If any of you Unix/Security people notice I messed up something, please tell me. I left "^], !sh" open on the telnet link for about 2 minutes and nearly had a heart-attack once I spotted it :D

#history #digital #retrogaming #retrocomputing #games #mud #muds #mist #rock #computers #emulation #emulators #vms #tops10 #museum #history #bletchleypark #simh #essex #uk #computinghistory #36bit #engineering #Linux #Security

(don't try this on a phone!)

I tried out #simh with #Unix 5 and 7 today. A remarkably modern operating system, though even the later version 7 lacks a lot of modern quality of life features that can be found in #Linux thanks to #bash. It's also cool to see how #C evolved from 1974 to 1979 to the first ANSI standard C89. It was far more simple in 1974, though I'm glad it evolved over time.

Anybody here who can tell me how this ps command in #Unix V4 on #simh #pdp11 works?
Regardles what I try I always get "No mem":
# ps
No mem

After more than half a century, UNIX v4 tape has been found in the University of Utah, and is now live in the Internet Archive!

#Unix #UNIXv4 #DEC #PDP11 #simh #Retrocomputing #TechNews #TechUpdates #OldUnix

https://officialaptivi.wordpress.com/2025/12/23/unix-fourth-edition-tape-has-been-recovered/

UNIX Fourth Edition tape has been recovered!

For half a century, the UNIX v4 tape was not found, until this year. Everything changed when staff members at the University of Utah have found the UNIX v4 tape while cleaning out storage rooms. That was a very strong sign that the computer history was preserved and archived by those who make archives of old operating systems and other computer-related things.

UNIX v4 was officially released for the DEC PDP-11/45 computers on November 1973, when those computers were the only computers eligible for this version of UNIX. Since then, it was thought to be lost until November 7th when the tape has been rediscovered. Apparently, this tape was sitting somewhere in one of the storage rooms in the University of Utah.

The Computer History Museum has further handled this by letting bitsavers.org conduct the recovery process, where the tape has been successfully recovered to a raw tape, which has then been uploaded publicly to the Internet Archive for publication.

For those who are eager to run UNIX v4 using the simulation program, simh, on your host PC, you can follow the instructions on this page.

The Internet Archive entry has very interesting pieces of history of this tape that said:

• UNIX V4 tape from the University of Utah, received by Martin Newell in June 1974 around when he modeled the Utah Teapot.
• This is the raw analog waveform and the reconstructed digital tape image (analog.tap), read at the Computer History Museum’s Shustek Research Archives on 19 December 2025 by Al Kossow using a modified tape reader and analyzed with Len Shustek’s readtape tool.
• The tape was found in July 2025 by Aleks Maricq in the storage closet of the Flux Research Group in the Merrill Engineering Building, among the documents of Jay Lepreau.
• It was brought to the Computer History Museum by Jon Duerig and Thalia Archibald.

This tape was preserved in the storage room for more than half a century before it’s found in July 2025, then discovered on November, before being uploaded to the Internet Archive on December 22nd.

#news #simh #Tech #Technology #Unix #UNIXFourthEdition #UNIXV4 #update

So it's back to 1974 on my @VoidLinux box as well ...

#unixv4
#simh
#pdp11
#classiccomputers

New Article: Exploring OpenVMS 7.3 with SIMH VAX on OpenBSD

- Host+simh networking (vether+tap)
- Installation
- User management
- Layered product installation
- TCP/IP Stack
- WASD web server

HTTPS: https://cryogenix.org/library/operating-systems/openvms-7-3-w-simh-vax-on-openbsd

HTTP: http://cryogenix.org/library/operating-systems/openvms-7-3-w-simh-vax-on-openbsd

(Update of original 2009 article)

#OpenVMS #OpenBSD #SIMH #VAX #RetroComputing

https://github.com/open-simh/simh/pull/505 ← There's a new emulator in open #SIMH for the #LINC, by @larsbrinkhoff. I will absolutely be running this on the hardware from my exhibit once the current exhibition finishes, and I'll work on getting the knobs and switches working accurately. I'll need to drive way more neopixels for that to work! #retrocomputing #vintagecomputing

Vintage Hardware Find Includes Time Capsule of Data https://hackaday.com/2025/07/16/vintage-hardware-find-includes-time-capsule-of-data/ #Retrocomputing #retrocomputing #virtualization #messageboard #vaxstationii #emulator #hardware #SIMH #bbs #DEC

Vintage Hardware Find Includes Time Capsule of Data - Before social media brought the Internet to the masses, and before even Napster, I... - https://hackaday.com/2025/07/16/vintage-hardware-find-includes-time-capsule-of-data/ #retrocomputing #virtualization #messageboard #vaxstationii #emulator #hardware #simh #bbs #dec

One thing that would be kind of neat: Proxmox integration for SIMH! I wonder how tedious it is to write a plug-in… #proxmox #simh #retrocomputing

Rebooting An 1973 Art Installation Running On A Nova - Electronics-based art installations are often fleeting and specific things that on... - https://hackaday.com/2025/05/12/rebooting-an-1973-art-installation-running-on-a-nova/ #datageneralnova #raspberrypi4 #synthesiser #teensy4.0 #neonlamp #pt8211 #ws2811 #simh #art

Rebooting An 1973 Art Installation Running On A Nova https://hackaday.com/2025/05/12/rebooting-an-1973-art-installation-running-on-a-nova/ #DataGeneralNova #RaspberryPi4 #synthesiser #neonlamp #Teensy40 #PT8211 #ws2811 #SIMH #Art

OK, so we have an installed #simh #netbsd #vax, lets setup a useful tap0 on the host:

% cat /etc/ifconfig.bridge0:
create
!/sbin/ifconfig tap0 create
!/sbin/brconfig $int add bge1 add tap0 up

"boot dua0" from simh this time, wait f.o.r.e.v.e.r for fontconfig on the first boot, mount an nfs exported pkgsrc from the host, a good sized /var/obj and we're ready to build

/9

#pkgsrc has no fewer than three different #simh packages. Lets pick #opensimh, because... it would take too long to explain (I also prefer my drama in non functional code and blinkenlights rather than human interactions)

With the config from the previous toot in netbsd-10.simh, the ISO in place, and permission and space to create the ra92 files, lets try "simh-vax netbsd-10.simh" and ... a complaint about the networking (oops, we'll come back to that), creating files and attaching and

/4

It has been a while since I setup networking on simh, so bear with me...

1) OK, so download the #netbsd #vax iso from https://cdn.netbsd.org/pub/NetBSD/NetBSD-10.0/images/
2) Create a #simh config file, with two virtual RA92 disks (In reality each 32kg of sharp cornered finger crushing metalwork), 512MB of memory & link to the ISO

set cpu 512m
set rq0 ra92
at rq0 /opt/vm/netbsd-10-vax.ra92
set rq1 ra92
at rq1 /opt/vm/netbsd-10-vax-pkgsrc.ra92
set rq2 cdrom
at rq2 /opt/vm/NetBSD-10.0-vax.iso
at xq0 tap:tap0
boot cpu

/3

Unfortunately, (or fortunately if you consider my living space), I do not have a VAX 11/780, only a VAXstation 4000, and further more I'm not even at said living space, so today we'll be going with a copy of #simh (or rather #opensimh) /2

So I had a realization: The QuickTime movie format would make a good format for archival and preservation of streaming tape data. https://eschatologist.net/blog/?p=409 #retrocomputing #simh

This video gives an in-depth look at what is currently the oldest known copy of 86-DOS, the antecedent to #MSDOS aka #PCDOS, where we go through the process of moving from CP/M, translating Z80 to 8086 code, and assembling it. Since this DOS predates the IBM PC, it must be simulated via #SIMH as a Gazelle with a Cromemco 4FDC controller. #retrocomputing https://youtu.be/Zd7T5euID1E

@tastytronic 33 instructions loaded in starting at `0200`. I'm chuffed it worked in vrs's branch of #simh!

https://zork.net/git/SpaceHobo/hellorld-pdp12 ← The `Makefile` in this repo will download and build all the tools you need to assemble and run this in an emulator!

RSX-11M Plus is a multiuser real-time operating system for the DEC PDP-11s. Works nice on #SIMH!

Progress on the #PiDP-11 kit last night.

The Raspberry Pi 3 A+ has been loaded with the #SimH software and various bootable OS images that can run on the PDP-11/70. Connected it to the GPIO interface on the back of the PCB where it will live. Powered it up for a "smoke test" and let it boot into the default "idled" program that runs some patterns on the LEDs.

Then inserted the panel switches and got them soldered in.

#RetroComputing #BlinkenLights #PDP

A while back, I stumbled onto Oscar's #PiDP-11 kit, a 6:10 scale replica of the PDP-11/70. As a fan of #RetroComputing, I decided to buy the kit and attempt to build it. It's powered by an RPi running #SimH, which gets wired up via GPIO to the front panel switches/lights, faithfully reproducing the functionality of the original.

Finally started building this evening and, after about an hour, managed to get all the diodes and resistors soldered on and the LEDs staged.

https://obsolescence.wixsite.com/obsolescence/pidp-11

@wuffel On the #RaspberryPi in the #PiDP8 #SimH with OS/8 is running.

A Weather Station Fit For A PDP-11 - The Digital Equipment Corp. PDP-11/70 is a masterpiece of Cold War-era industrial design. This mic... more: https://hackaday.com/2019/03/31/a-weather-station-fit-for-a-pdp-11/ #classichacks #raspberrypi #emulation #pidp #simh #bsd