Mount a tape 2868

Louis Krupp

i had some stuff from the late 60s and early 70s replicated on three different tapes (over the years copying from 800bpi to 1600bpi to 6250bpi tape) ... but all in the same datacenter library in the mid-80s. it included some stuff on periodically monitoring system activity and using the information for dynamic adaptive feedback control. i had created dynamic adaptive feedback scheduler in the 60s as an undergraduate that included fairshare as a default policy ... that was shipped in cp67. much of the code was dropped in the morph from cp67 to vm370. however, i was given a chance to re-introduce it with the resource manager (shipped spring 1976).

for a little more drift, the resource manager was selected to be the guinea pig for priced kernel software. with the unbundling announcement on 6-23-68 plus 1, application software started being charged for ... but kernel software was still shipped free (under the justification that it was needed to run the hardware ... aka bundled). by the mid-70s, various factors (like 370 clones) were contributing to pressure to pricing kernel software. i got to spend six months or so on and off with business and pricing people on policies for pricing kernel software. misc. past bundling-unbundling posts

anyway, by the mid-80s, some people from corporate came looking for early examples of periodic monitoring of system performance activity ... having to do with some litigation or patent issue. i went to retrieve the code and found that all three tapes had been written over. apparently there was some problem in the datacenter with operators randomly selecting tapes to be mounted as scratch (i.e. the ring was inserted for a request to mount a scratch tape for writing).

recent post reproducing part of the resource manager "blue" announcement letter (actually beige at this time, but still commonly referred to as "blue" ... i don't actually still have a paper copy but was presented an engraved plaque of the announcement letter that has survived).