Shmuel Metz (Seymour J.) wrote:
In <m38w8m5ki2....@garlic.com>, on 04/17/2010
at 08:30 AM, Anne & Lynn Wheeler <l...@garlic.com> said:
I didn't remember block-mux being on 360
Consider the model number of the fixed-head disk. The 2 says that it's a
S/360 device.
-----------------------------------------<snip>----------------------------------------
I suspect that 2305 was an outgrowth of the 2302, not necessarily a
"new" device. The 2305 was available with selector channel interfaces
before the blk-mux interfaces. At NCSS we were told that it took a
complete selector subchannel, with eight "exposures", to function
properly so we configured them (16 devices) to run off 2860 Selector
channels hanging off a 370/168 system.
We did some strange things with those devices, using multiple exposures
to access individual blocks on the track, etc. via software. A gentleman
named Grant Tegtmeier wrote the CP67/CMS suppport for the device,
complete with our "strange usage", over the course of two weekends,
while subsisting entirely on coffee and Chesterfield Kings. The man was
best characterized as "hours of boring nothingness, punctuated by
moments of sheer absolute genious". I knew him in college, at MTU.
Rick
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