RK05 packs

[Paul Koning]

> On Sep 7, 2016, at 8:51 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
> 
>> From: Ethan Dicks
> 
>> 12-sector packs are abundant compared to 16-sector packs
> 
> Really? Most of the RK05 packs I've seen for sale on eBay in the last couple
> of years have been 16-sector - so I naturally assumed they were more common.

Interesting.  They are best known as PDP-8 packs, but there's another use for them and I wonder if that is relevant.  Some IBM systems -- the 360 model 44 for example -- have a "2315" drive which is an RK05.  And I vaguely remember seeing 16 sector slots in that pack the one time I pulled it out of our college 360/44.  The IBM manual speaks of 8 sectors per track, 366 bytes per sector.  Weird.  But 200 cylinders plus 3 spare, just as for the RK05s we know.

	paul