An historical nit about FDDs

Jon Elson elson at
Sat Jul 14 10:50:55 CDT 2018

On 07/14/2018 07:57 AM, Noel Chiappa via cctalk wrote:
>      > From: Jon Elson
>      > I THINK the 370/145 used the same drive.
> The "IBM's 360 and Early 370 Systems" book doesn't say so explicitly (it just
> says Minnow - the one with the solenoids - was a"incorporated in .. the
> System/370 processors", pg. 517), but given that the follow-on drive
> (Figaro/Igar) didn't start shipping until 1973 (pg. 519), and the /145 started
> shipping in 1971, it pretty much had to have had a Minnow.
Well, there were two major variants of the 370/145, that had 
major changes at least to the power system.
The first version had many small power regulator modules, 
the later had two HUGE regulators (390 A each, at +1.25 V 
and -3 V).  So, they could have updated a bunch of other 
features at the time of that change.


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