dmr@research.UUCP (12/08/84)
I happened to dredge up an old notebook and found a listing of the PDP-7 version of dsw. Because several people have approached me recently about reviving a version of PDP-7 Unix as a sort of paleontological exhibit, and because the subject has been discussed here, I thought people might be interested in seeing the code. I first considered net.sources, but decided not to carry whimsy too far. Dennis Ritchie Notes: 1) The assembler has Knuth-style temporary labels but no literals. 2) The name of the current directory was evidently ".." 3) Formatting is faithfully reproduced. 4) "sys save" makes a core image. ------ " dsw lac djmp dac .-1 oas cla cma tad d1 dac t1 sys open; dd; 0 1: lac d2 sys read; dir; 8 sna sys exit lac dir sna jmp 1b isz t1 jmp 1b wr: lac d1 sys write; dir+1; 4 lac d1 sys write; o12; 1 sys save do: sys unlink; dir+1 sys exit d1: 1 d2: 2 o12: 012 t1: 0 djmp: jmp do dd: 056056; 040040; 040040; 040040 dir: .=.+8
jbn@wdl1.UUCP (01/16/85)
Keeping a V7 up and running is an excellent idea, as a reminder of what
UNIX used to be before it got big and fat.
We at Ford Aerospace were at one time the largest commercial user of
UNIX outside the Bell System, with 13 systems running PWB/Unix. (About 5
are still running PWB/Unix, but we are slowly converting them to system V.)