13 Jul
2024
13 Jul
'24
6:25 a.m.
I think my work was in the summer of 1979 or possibly 1980, before the
FRS in Oct. 1980. People were happy because mass production of the
ucode ROMs hadn't started yet. I was using one of the 2~4 11/750
prototypes which were on concrete blocks in a lab, and the 11/730
breadboard was standing up on a table (no box) with its boards fanned
out. And it was during the gasoline shortage. Maybe I'll find
something about it later.
- Aron
On 7/12/24 18:03, John Levine wrote:
It appears that Dave Horsfall
<dave(a)horsfall.org> said:
On Sat, 12 Jul 2024, John R Levine wrote:
The details are a litle dim after 45 years, but there was a MOVTUC
instruction in the inner loop of printf that scanned for the null at
the end of the string. The /750 had a microcode bug that didn't
matter for the way DEC's software used it but broke the libc and
I think also the kernel version. MOVTUC sets six registers and
we probably used one they didn't.
Bill replaced it with a few simpler instructions and the comment
; Comet sucks
R's,
John
PS: For you young folks, Comet was DEC's internal project name for the /750.
Our Vaxes ran Unix so it was all C other than a
few things like tracking
down a bug in the 11/750's microcode that broke an instruction in the
inner loop of printf(). [...]
Do tell...