Billy Pettit real disappointment

[Jim Battle]

Chuck Guzis wrote:
> On 30 Jun 2007 at 20:21, Peter C. Wallace wrote:
> 
>> 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.

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.