21 Feb
2006
21 Feb
'06
7:28 a.m.
On 2/20/06, dmr(a)plan9.bell-labs.com <dmr(a)plan9.bell-labs.com> wrote:
Here at U.C. San Diego, the Electrical Engineering and Computer
Science department received an AT&T donation of a whole lab full of
3B2 computers for instructional purposes.
I had the unenviable task of trying to teach a course based around
Assembly language and interfacing to higher-level languages (like C)
and OS functionality. Using the 3B2, for which the official AT&T
position was that these computers were not intended to be programmed
in assembly language, and the appropriate documentation was sort of
non-existent to us outsiders.
I remember when I discovered that the assembler would generate
instructions different from those that were present in the source
code, as demonstrated by running the object-code disassembler.
carl
--
carl lowenstein marine physical lab u.c. san diego
clowenst(a)ucsd.edu
I'm
interested in acquring an AT&T 3b2 computer. One of these systems
used to run a famous public UNIX system "killer". They also run #5ess
telephone switches, however the OS is different in that case
(DMERT/UNIX-RTR instead of whatever the consumer-level 3b2 runs).
If anyone has information on where to acquire
these (I saw the recent
discussion on 3b1s and I know they are more prolific than 3b2s-- infact
a friend of mine used to have a UNIX PC which we set up a BBS on).
The 3B2 was not the same machine as the one in 5ESS, which
was/is the 3B20D, a fairly large duplexed machine (two processors
that mutually checked each other). The 3B2 was a desktop.
The 3B20D wasn't sold commercially, as far as I know. There
was a 3B20S (multi-cabinet) that at least nominally
was commercially available.
Their ISAs were not quite the same, but some assembler language
tricks made the assembler-level languages look quite similar.