From: Warner Losh <imp@bsdimp.com>
To: Clem Cole <clemc@ccc.com>
Cc: The Unix Heritage Society mailing list <tuhs@tuhs.org>
Subject: Re: [TUHS] Early Linux and BSD
Date: Tue, 21 Jan 2020 12:14:45 -0700 [thread overview]
Message-ID: <CANCZdfoEAm5=thcZNKjF_5tcMH=iFP_E+QeVUhxRo154G1=pCA@mail.gmail.com> (raw)
In-Reply-To: <CAC20D2MeAtw4fLoGbtqhVfH98xo1oFuAXXrnHfMXEnJLLK_R5w@mail.gmail.com>
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On Tue, Jan 21, 2020, 11:46 AM Clem Cole <clemc@ccc.com> wrote:
> sorry... all *MPU* boards had to be the revision but we may have done
> the same with the CPU boards.
>
When did Masscomp ship their first MP system?
Warner
On Tue, Jan 21, 2020 at 1:43 PM Clem Cole <clemc@ccc.com> wrote:
>
>>
>>
>> On Tue, Jan 21, 2020 at 12:18 PM Jon Steinhart <jon@fourwinds.com> wrote:
>>
>>> My memory is very very very fuzzy on this. I seem to recall that
>>> microcode
>>> state was pushed onto a stack in certain cases,
>>
>> State, not the code.
>>
>> In fact, Masscomp having built the first MP UNIX box, ran into this
>> problem early on. Different processor stepping had different internal
>> microcode state on the stack after an IRQ. If you resumed with a processor
>> that was a different processor revision, the wrong state was returned.
>>
>> Will may remember this, but Masscomp issues strick orders to the FE that
>> all CPU boards had to be the revision. You could not just swap a CPU
>> board, they had to go as sets. It was a real bummer.
>>
>> Moto fixed that with the 020 and later devices as more people made MP
>> systems.
>>
>>
>>
>>
>>
>>> ... just heard grumbles from other folks about it.
>>>
>> Probably me ... it took me, tjt and Terry Hayes about 3-4 weeks to
>> figure out that problem. It was not originally documented, other than
>> to state on certain faults X bytes of reserved information was pushed on
>> the stack.
>>
>> BTS: I don't remember, but it may have started with the 68010.
>> Becuase before that, the 'executor' was wait stated and the fixor handled
>> and fixed the fault so the 68000 never actually saw fault in the original
>> Masscomp CPU board. The "MPU" board was the same board with a couple of
>> PAL's changed and an 68010 as the executor. It was allowed to actually
>> fault and do something else while the fixor corrected the fault. But the
>> key is that when the fault was repaired, another executor on a different
>> MPU board could be the processor that 'returned' from the fault. That
>> ended up being a no-no.
>>
>
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next prev parent reply other threads:[~2020-01-21 19:15 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-17 16:01 [TUHS] On the origins of Linux - "an academic question" Arrigo Triulzi
2020-01-17 16:53 ` Warner Losh
2020-01-17 17:08 ` Arrigo Triulzi
2020-01-17 17:25 ` Brantley Coile
2020-01-17 19:59 ` Arno Griffioen
2020-01-18 3:50 ` Theodore Y. Ts'o
2020-01-18 4:19 ` [TUHS] Early Linux and BSD (was: On the origins of Linux - "an academic question") Greg 'groggy' Lehey
2020-01-18 15:25 ` Larry McVoy
2020-01-18 16:19 ` reed
2020-01-19 2:49 ` Theodore Y. Ts'o
2020-01-19 3:12 ` Greg 'groggy' Lehey
2020-01-19 3:47 ` [TUHS] Early Linux and BSD Warren Toomey
2020-01-19 3:51 ` Greg 'groggy' Lehey
2020-01-19 3:58 ` [TUHS] Early Linux and BSD (was: On the origins of Linux - "an academic question") Greg 'groggy' Lehey
2020-01-19 13:25 ` Theodore Y. Ts'o
2020-01-19 13:48 ` Clem Cole
2020-01-20 3:32 ` Greg A. Woods
2020-01-20 3:51 ` George Michaelson
2020-01-20 3:59 ` [TUHS] Early Linux and BSD Jon Forrest
2020-01-20 17:19 ` [TUHS] Early Linux and BSD (was: On the origins of Linux - "an academic question") Clem Cole
2020-01-20 17:49 ` Warner Losh
2020-01-20 19:00 ` Clem Cole
2020-01-20 18:04 ` Larry McVoy
2020-01-20 18:09 ` David Barto
2020-01-20 18:34 ` [TUHS] Early Linux and BSD Arthur Krewat
2020-01-20 19:18 ` [TUHS] Early Linux and BSD (was: On the origins of Linux - "an academic question") Clem Cole
2020-01-20 19:46 ` Jon Steinhart
2020-01-20 20:15 ` Clem Cole
2020-01-21 6:58 ` [TUHS] Early Linux and BSD Lars Brinkhoff
2020-01-21 14:30 ` Clem Cole
2020-01-21 17:17 ` Jon Steinhart
2020-01-21 17:22 ` Warner Losh
2020-01-21 17:25 ` Jon Steinhart
2020-01-21 18:43 ` Clem Cole
2020-01-21 18:44 ` Clem Cole
2020-01-21 19:14 ` Warner Losh [this message]
2020-01-21 20:27 ` Clem Cole
2020-01-22 0:14 ` [TUHS] Early Linux and BSD (was: On the origins of Linux - "an academic question") Greg A. Woods
2020-01-21 0:44 ` Bakul Shah
2020-01-20 19:09 ` Theodore Y. Ts'o
2020-01-20 19:51 ` Clem Cole
2020-01-20 23:04 ` Greg A. Woods
2020-01-21 0:13 ` Warner Losh
2020-01-21 23:45 ` Greg A. Woods
2020-01-18 15:30 ` [TUHS] On the origins of Linux - "an academic question" Larry McVoy
2020-01-17 23:11 ` Andrew Warkentin
2020-01-17 23:20 ` Rob Pike
2020-01-17 23:38 ` Brantley Coile
2020-01-18 0:23 ` Wesley Parish
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