The Perfect Computer - 36 bits?
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From: Rich Alderson on 13 Apr 2007 14:28 jmfbahciv(a)aol.com writes: > In article <rm8u13d6epff3j0t35arr37ckqem4uns73(a)4ax.com>, > Brian Inglis <Brian.Inglis(a)SystematicSW.Invalid> wrote: >> Most OSes, including DEC, had numbers "hardwired" in the software, for >> disk drives, models, geometries, and capacities. > Huh? Do this exercise. RUN MONGEN and then answer the questions. Which simply asks *if* you have any of the recognized peripheral types, and if you do, *how many* of them you want to support in your configured monitor. But that simply ends up including or not including the "'hardwired' numbers" for those devices by including the appropriate drivers or not. There's no disagreement here. -- Rich Alderson | /"\ ASCII ribbon | news(a)alderson.users.panix.com | \ / campaign against | "You get what anybody gets. You get a lifetime." | x HTML mail and | --Death, of the Endless | / \ postings |
From: Eric Smith on 13 Apr 2007 21:17 nmm1(a)cus.cam.ac.uk (Nick Maclaren) writes: > No, but nor could the Z80 compete on industry-quality functionality and > reliability. The Z80 was *much* more reliable than any PDP-11 system, which is not surprising since it's an apples-to-oranges comparison. There's no reason why a Z80-based system could not have been made as reliable as a PDP-11 system. Possibly some were, but certainly not your average cheap hobbyist-grade Z80 computers, running cheap hobbyist-grade software. > I know quite a few people who used Z80s for that, and they > never really cut the mustard for mission-critical tasks I saw quite a few Z80s used for mission-critical critical tasks. More Z80s have been used for LIFE-critical tasks than the total number of PDP-11 computers manufactured.
From: Terje Mathisen on 14 Apr 2007 07:13 Eric Smith wrote: > nmm1(a)cus.cam.ac.uk (Nick Maclaren) writes: >> I know quite a few people who used Z80s for that, and they >> never really cut the mustard for mission-critical tasks > > I saw quite a few Z80s used for mission-critical critical tasks. Back in 1981 we had 12 (or 16?) channel 'Acoustic Emission' gear using a dedicated Z80 per channel, this was used for monitoring stuff like building platforms, offshore oil rigs and other relatively 'mission-critical' applications. > More Z80s have been used for LIFE-critical tasks than the total > number of PDP-11 computers manufactured. Almost certainly true. Terje -- - <Terje.Mathisen(a)hda.hydro.com> "almost all programming can be viewed as an exercise in caching"
From: Nick Maclaren on 14 Apr 2007 07:50 In article <5jp6f4-d3b.ln1(a)osl016lin.hda.hydro.com>, Terje Mathisen <terje.mathisen(a)hda.hydro.com> writes: |> Eric Smith wrote: |> |> >> I know quite a few people who used Z80s for that, and they |> >> never really cut the mustard for mission-critical tasks |> > |> > I saw quite a few Z80s used for mission-critical critical tasks. |> |> Back in 1981 we had 12 (or 16?) channel 'Acoustic Emission' gear using a |> dedicated Z80 per channel, this was used for monitoring stuff like |> building platforms, offshore oil rigs and other relatively |> 'mission-critical' applications. The context of this thread was computer communications, which has rather different requirements. I can't tell you what the problems were in detail, but they were more to do with "operating system" functions and peripheral driving than simply not crashing due to hardware problems. Regards, Nick Maclaren.
From: jmfbahciv on 14 Apr 2007 07:23
In article <mddd5285dtk.fsf(a)panix5.panix.com>, Rich Alderson <news(a)alderson.users.panix.com> wrote: >jmfbahciv(a)aol.com writes: > >> In article <rm8u13d6epff3j0t35arr37ckqem4uns73(a)4ax.com>, >> Brian Inglis <Brian.Inglis(a)SystematicSW.Invalid> wrote: > >>> Most OSes, including DEC, had numbers "hardwired" in the software, for >>> disk drives, models, geometries, and capacities. > >> Huh? Do this exercise. RUN MONGEN and then answer the questions. > >Which simply asks *if* you have any of the recognized peripheral types, and if >you do, *how many* of them you want to support in your configured monitor. That was a maximum number, not a hard-wired number of the device. The reason for this was to reserve enough bits in certain fields. We hadn't figured out how to extend field sizes while running the monitor; today's lingo calls this plug'n'play. > But >that simply ends up including or not including the "'hardwired' numbers" for >those devices by including the appropriate drivers or not. > >There's no disagreement here. The only hardwired numbers were the numbers the hardware had hardwired. The purpose of MONGEN was to make as many things possible a parameter. IOW, not hardwired. /BAH |