[Unix-jun72] Disassembler in progress

Guys, I'm writing a PDP-11 a.out disassember. I think it will be useful for a couple of reasons: - we will be able to convert the extant 1972 binaries back into some form of source code. It won't be as good as the real thing, but it will be better than the binary. - we have some source code in fragmentary form on the s1 tape, see http://minnie.tuhs.org/UnixTree/1972_stuff/. Some of the fragments are identifiable, some are not. We might be able to use the diassembled binaries to identify some of the fragments, and even reconstruct a hybrid original/diassembled version of the source for some of the 1972 applications. Right now, here's what I've got: disassembly of the top of 1972 ls: sys break: 00 mov $01,044260 mov sp,r5 mov (r5)+,043732 tst (r5)+ dec 043732 mov 043732,043734 bgt 040056 mov $042542,r5 mov (r5)+,r4 cmpb (r4)+,$055 bne 040174 dec 043734 and the top of the frag19 file: sys break; end+512. mov $1,obuf mov sp,r5 mov (r5)+,count tst (r5)+ dec count mov count,ocount bgt loop mov $dotp,r5 loop: mov (r5)+,r4 cmpb (r4)+,$'- bne 1f dec ocount At the moment it's a 1-pass disassembler. I want to make it 2-pass: on the first pass I will try to identify labels for branches, functions, strings and variable locations (and given them arbitrary names); on the second pass I'll print out the instructions with reference to the labels. None of the binaries have symbol tables, unfortunately. It's a start, anyway. Warren