[COFF] machine code translation,as mental architecture models

[Aron Insinga]

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 at horsfall.org> said:
>> On Sat, 12 Jul 2024, John R Levine wrote:
>>
>>> 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...
> 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.