The MACRO-10 assembler used a keyword ASCIIZ to store that
7-bit/1-bit-wasted ASCII format.
MOVEI 0,[ASCIIZ /Hello there
/]
for example. It was the defacto standard for null-terminated ASCII strings.
When I later moved to C on 8/16-bit computers, I remember thinking
"what's with this signed 8-bit char thing?" ;)
There was also SIXBIT - almost everything ASCII had, but only upper
case. The filesystem used that for filenames and extensions, and it was
used in a few other areas. So any library calls like open() would have
had to convert the ASCII filename to SIXBIT before doing any monitor calls.
On 9/18/2017 9:50 AM, Clem Cole wrote:
On Sun, Sep 17, 2017 at 11:22 AM, Arthur Krewat <krewat(a)kilonet.net
<mailto:krewat@kilonet.net>> wrote:
I have a C compiler for TOPS-10 that I got off the Internet back
in 1988. Still haven't messed around with it enough to get it to
run, but ...
There was a PDP-10 C compiler in the late 1970s, that was kicking
around CMU, MIT and Stanford which we used to write backup10 and and
an implementation of tar. IIRC, it was based on the the Ritchie
front end and was V6 in syntax (i.e. pre-V7 or typesetter C - aka
'White Book). I've forgotten the rules of chars, but I remember you
had to be careful. I think it was 4 9-bit chars to transfer things
(4*9=36 bits), but I think I remember there were cases on output that
it wanted to wash it through a 7-bit PDP-10 char (5*7+1 =36bits) which
was the 'norm' for most languages like SAIL, BLISS et al.
I did not mess with much, but that time, I was transitioning from the
10's to UNIX by that time. I added support for the -20's dumper
tapes to backup10 which were almost but not quite the same. But that
was the last I messed with it. Mike Accetta and Fil Aliva (of CMU Mach
fame) I remember had their had in that subsystem, at one point. And
of course Danny Klein is always a good one from those days to ask too.
I'll see if I can dig them up and ask.