winscape 2266

it is possible as the heads flew closer it was easier to polish a flat disk to tolerance than it was to manufactor a drum to tolerance.

there was a 2303 drum for 360 ... that did transfer at about 300kbyte-sec ... and a 2301 version of the 2303 drum that ganged four r-w heads in parallel that did transfer about 1.2mbyte-sec. they both had approx. 4mbyte capacity.

for 370 ... there was 2305, two versions, one with standard rotational delay and capacity of about 12 mbytes, and one with half the standard rotational delay, half the capacity and half the tracks (although the same number of r-w heads ... it just that pairs of r-w heads were offset 180degrees for the same track ... allowing avg. rotational delay to be cut in half).

a memory vendor produced a run of emulated 2305s that were available internally under the model number "1655". they were reputed to be made of memory chips that had failed some standard memory performance criteria ... but still had useuable bits. the i-o related simulation and latency basically allowed the controller to compose operations so that it could still make use of the chips.

picture of 2301

two pictures of 360-67 components, the first-upper picture is of smp two processor 360-67 and 2301 is sort of left of middle in the picture; the second-lower picture of machine room with 2301 in upper right corner,

mentions using two 2301 drums on 7094 for ctss

component price list of 360-67 system ... including 2301

misc. past posts mentioning 2301 &-or 2305

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