Multics Intro Course (1978)(archive.org)
archive.org
Multics Intro Course (1978)
https://archive.org/details/bitsavers_honeywellmroCourseOct78_20488346
9 comments
More Multics resources here: https://www.multicians.org/biblio.html
Specially worthwhile to read is how Multics security model compares to UNIX.
https://multicians.org/b2.html
And how much safer PL/I was, even when compared against C17.
https://multicians.org/b2.html
And how much safer PL/I was, even when compared against C17.
Also see https://ban.ai/ and https://ban.ai/Multics/doc/
From page 17:
> ON MOST LARGE SCALE HONEYWELL EQUIPMENT, A BYTE EQUALS 9 BITS
Wait, 9 bits?
> ON MOST LARGE SCALE HONEYWELL EQUIPMENT, A BYTE EQUALS 9 BITS
Wait, 9 bits?
Yes and it wasn’t alone, I’ve programmed on several machines that didn’t have 8-bit organization. The DEC PDP-9 and some others had 18 bit words and the big CDC 6600 series had 60 bit words with 10 chars per word, not exactly Unicode.
It was a 36-bit machine that supported both 6 and 9-bit bytes, though since Multics was case sensitive (the first case-sensitive/lowercase OS I'd ever used) IIRC the sixbit mode was not used by Multics.
The most popular 36-bit hardware, the PDP-6/PDP-10/DEC-20 family, supported addressable bytes from 1-63 bits in width. Doesn't it seem odd that C defaults to octal? Because of the legacy of earlier machines on which octal was more natural, C & Unix picked it up too, despite being developed on the PDP-7 and later PDP-11.
I think the 8-but byte might have started out as an IBMism.
The most popular 36-bit hardware, the PDP-6/PDP-10/DEC-20 family, supported addressable bytes from 1-63 bits in width. Doesn't it seem odd that C defaults to octal? Because of the legacy of earlier machines on which octal was more natural, C & Unix picked it up too, despite being developed on the PDP-7 and later PDP-11.
I think the 8-but byte might have started out as an IBMism.
It makes a lot of sense if you write octal instead of hexadecimal.
9 * 4 = 36-bit word.
“Linus...is a powerful and easy-to-use facility for accessing databases from a remote terminal.”