On Thu, 20 Feb 2003 23:49:38 +0800, John Summerfield <[EMAIL PROTECTED]> wrote:
>> On Thu, 2003-02-20 at 01:00, John Alvord wrote: >> > And Lord protect you if the packaging accidently contained materials >> > which generated gamma rays. Another tale of woe from the IBM 1980s >> >> Gamma seems odd, it doesn't interact much most times, now alpha emitters >> I could believe. Was it alpha or gamma emitters they got in their materials ? >> > >I recall back when we were getting round to 256K chips that cosmic rays were >becoming a problem and that chips weren't going to be made much denser. > >What happened? The cosmic ray scientist I talked with at Research in the middle 1980s said they spotted a pattern on No Trouble Found on channel Cache memory. The frequency was doubled in Denver - which has twice the number of cosmic ray bursts compared to sea level. Eventually IBM set up a several month long trial in a high altitude ghost town. The 308X was set up with some PC controllers which monitored for these transient conditions. At the same time, they arranged to get records of cosmic ray bursts at a (New Mexico?) radio observatory. The occurance of transient channel cache memory matched the radio observatory bursts quite closely. He never told me how the problem was cured. Maybe some more shielding? I seem to remember some customers who were advised to move their mainframe to lower in a tall building... the concrete was an effective barrier to the cosmic rays. john alvord
