multitasking on PDP-11/03

I thought I better check that I could still run MINI-UNIX and I notice the usual instructions floating around are somewhat oblique: # Prepare the RK05 boot drive - this uses the tape-to-disk utility that is part of the MINI-UNIX distribution tape sim> set cpu 11/40 Disabling XQ sim> set cpu 64k sim> set tm0 locked sim> attach tm0 mini-unix_120679.tap TM: unit is read only sim> attach rk0 rk0 sim> attach rk1 rk1 sim> d cpu 100000 012700 sim> d cpu 100002 172526 sim> d cpu 100004 010040 sim> d cpu 100006 012740 sim> d cpu 100010 060003 sim> d cpu 100012 000777 sim> g 100000 Simulation stopped, PC: 100012 (BR 100012) sim> g 0 =tmrk disk offset 0 tape offset 100 count 1 =tmrk disk offset 1 tape offset 101 count 3999 = Simulation stopped, PC: 137274 (TSTB @#177560) # Boot MINI-UNIX sim> boot rk0 @rkmx RESTRICTED RIGHTS USE, DUPLICATION OR DISCLOSURE IS SUBJECT TO RESTRICTIONS STATED IN YOUR CONTRACT WITH WESTERN ELECTRIC COMPANY, INC. ;login: root # ls -l / total 168 drwxrwxr-x 2 bin 1136 Sep 18 01:02 bin drwxrwxr-x 2 bin 1824 Sep 18 01:24 dev drwxrwxr-x 2 bin 496 Sep 18 01:47 etc -rwxrwxrwx 1 root 19208 Sep 4 03:18 hpmx drwxrwxr-x 2 bin 464 Sep 4 03:37 lib drwxrwxr-x 2 bin 32 May 13 1975 mnt -rwxrwxrwx 1 root 19010 Sep 18 01:18 mx -rwxrwxrwx 1 root 19010 Sep 18 01:28 rkmx -rwxrwxrwx 1 root 19148 Sep 4 03:15 rpmx drwxrwxrwx 2 bin 272 Sep 18 01:27 tmp drwxrwxr-x 13 bin 240 Jun 17 13:38 usr # But note this is for the PDP 11/40, I tried with set cpu 11/03 but for some reason this halts early in the startup. If you are interested in a purely floppy-based version then there was a later variant of MINI-UNIX renamed as LSX detailed here: http://www.mailcom.com/lsx/ This is quite neat since there are floppy images for various pieces of the system so you can compile a C program just using floppies. Here is the history of MINI-UNIX and its descendants, scroll down to Heinz Lycklama's email: http://minnie.tuhs.org/pipermail/pups/2001-March/000273.html