16 Jul
2021
16 Jul
'21
8:19 p.m.
On Fri, Jul 16, 2021 at 4:05 AM Lars Brinkhoff <lars(a)nocrew.org> wrote:
Clem Cole wrote:
Ah - that makes sense. I never programmed the Honeywell in anything but
Dartmouth BASIC (mostly) and any early FORTRAN (very little) and the whole
idea of storage size was somewhat oblivious to me at the point as I was a
youngster when I did that. Any idea did the Honeywell treat chars as
36-bit entities also? Steve, maybe you remember?
Also, please remember that the standard does not yet exist for a good 10
years ;-) At this point, the 'standard' was the Ritchie Compiler for the
PDP-11.
At the time, we to run wanted the program on all of the UNIX/v6 systems and
CMU's version of TOPS-10 and later TOPS-20 as an interchange format. Thus,
I have memories of having to use the "c =& 0177" idiom in the
backup/dumper program in a number of places [remember tar does not yet
exist, and tp/stp was a binary program]. Beyond that, I don't remember
much about the running C on the 10s. I think we started trying to move
Harvard's stp to TOPS-10, but ran into an issue [maybe the directory size]
and stopped. Since backup (dumper) was heavily used, we were trying to get
IUS and SUS to be able to be backed up and handled the same way the
operators did the backup for the 10's. In my own case, I had learned SAIL
(and BLISS) on the 10s before C on the PDP-11, plus this was an early C
program for me, maybe my second or third non-trivial one after I worked
with Ted on fsck, so coming from the PDP-10/SAIL/BLISS *et al *world, 7-bit
chars certainly seemed normal. I also remember having an early 'ah-ha'
moment, when the difference between a 7-bit and 8-bit char started to
become important.
Clem
ᐧ
The 'second' C compiler was a PDP-10
and Honeywell (36-bit) target
Alan Synder did for his MIT Thesis. It was originally targeted to ITS
for the PDP-10, but it ran on Tops-20 also. My >>memory<< is he used
a 7-bit Character, ala SAIL, with 5 chars stored in a word with a bit
leftover.
On ITS it only ever stored characters as full 36-bit words! So sizeof
char == 1 == sizeof int. This is allowed per the C standard. (Maybe it
was updated somewhere else, I dunno.)