The Perfect Computer - 36 bits?
|
From: jmfbahciv on 17 Apr 2007 07:59 In article <doc7235eie7g0pmhrvvq1eu4kqp8fa6qu1(a)4ax.com>, David Powell <ddotpowell(a)icuknet.co.uk> wrote: >In article <5jp6f4-d3b.ln1(a)osl016lin.hda.hydro.com>, > Terje Mathisen <terje.mathisen(a)hda.hydro.com> in >alt.folklore.computers wrote: > >>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. >> > >We had both, 11/23 with a few 4 channel async cards as data >concentrators / protocol convertors to multiple Z80s as embedded >real-time controllers. Not much difference in hardware reliability >after infant mortality, provided appropriate PSUs and fans. Most of >the early Z80 failures were PSU, charge-pumps from the +5 for the >RS232 drivers that slowly declined from 10V ish to not much over a >couple of years. Software reliability for the 11steadily improved >over the years, easy to investigate post-mortem, and add robustness >where necessary. The Z80s were just replaced, usually without >investigation. > > >>> More Z80s have been used for LIFE-critical tasks than the total >>> number of PDP-11 computers manufactured. >> >>Almost certainly true. >> > >Not surprising, after about 1979, every DEC sales office had painted >on the wall. "Thirty-two bits good, sixteen bits bad." And 36 was punishable by death. /BAH |