December 8, 1984 Dennis Ritchie posted the following:
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
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.
sys open; dd; 0
sys read; dir; 8
sys write; dir+1; 4
sys write; o12; 1
sys unlink; dir+1
djmp: jmp do
dd: 056056; 040040; 040040; 040040