30 Jun
2007
30 Jun
'07
10 p.m.
Chuck Guzis wrote:
On 30 Jun 2007 at 20:21, Peter C. Wallace wrote:
I'm in the middle of reading "IBM's Early Computers," by Bashe, Johnson,
Palmer, and Pugh. I have owned it for quite a while but never made to
the time to read it. It is full of interesting stories ... from IBM's
perspective, of course.
Anyway, in the chapter dealing with RAMAC, it mentions that one approach
they attempted was the idea mentioned above -- solenoids that are
additively summed where the effect of the actuation of the solenoids is
arranged as a power's of two. Although started in Feb 1958 (see p.
304), they gave up on that idea in favor of a "fluid adder" -- pumping
the positioning cylinder with fixed amount of hydraulic fluid to advance
the head one track.
Wasn't there a 5-1/4 hard drive (late 80s)
that did a similar thing, some kind
of telescoping binary length set of solenoids (Ontrax?)
Did you know Joe Koenig? He ran that outfit while it lasted, but I
didn't think that they produced anything but a prototype before they
discovered that there were fatal problems with the idea.