Question re: 8" drive form-factor

[Eric Smith]

Steven Hirsch wrote:
> I found the OEM manual on bitsavers and it's actually the 'R' model 
> that matches what I believed to the industry form-factor of 8.5" 
> width.  The "standard" (non-R) model is 9.5" wide.  Odd standard, 
> since I've never seen another 8" drive that size.
Ah, that was it.  They made the "R" model narrower to make it easier to 
fit them side by side in a rack.

I'm guessing that the 9.5" size might match the size of the genuine IBM 
33FD, 43FD, or 53FD drives.   Although I have some 53FD drives, I've 
never taken them out of the equipment they're installed in, so I haven't 
had occasion to measure their dimensions.

Eric