[TUHS] comparing s1 frags, s2 bits, 1ed and jun72 print out

[Tim Newsham]

Some notes about the s1 frags in the 1972_stuff archive in relation
to 1st edition manual, s2 files and the jun72 printout:

- s1 init mounts several filesystems and runs several commands directly.
   s2 init doesn't mount anything.  init.s in the jun72 printout mounts
   /usr.  The 1ed manual describes init as mounting an rk disk on /usr.
- init.s uses syscall to get console switches.  The s2 init and the
   init.s in jun72 printout read them directly.
   S1 uses syscall 38.  jun72 printout only has syscalls through 33.
   1ed manual only lists syscalls through 33 (SYS ILGINS (II)).
- init.s compares with $173030.  The 1ed manual and jun72 printout
   compare with $73700 as does the init from s2.
- ls.s uses /etc/passwd.  1ed ls.s uses /etc/uids as passwd is not
   readable by normal users.

I think this points to the jun72 bits being closely related to 1ed,
the s2 files as being slightly newer, and the s1 frags as being a
bit newer than that.

Tim Newsham
http://www.thenewsh.com/~newsham/