Nope. not the same. did a page by page comparison, *very* close on
most of the specs - but when you get to a J1 pinout diagram for the
cable, there are significant differences. The 51/52 uses extra lines
that the B51/52 shows as not used.
Steve
On 10/5/2018 3:43 PM, Fred Cisin via cctalk wrote:
On Fri, 5 Oct 2018, steve shumaker via cctalk wrote:
I've scanned something called the "MPI Flexible Disk Drive
Interfacing Guide" for the Model 51/52 floppy units
Is that the same as:
http://www.osiweb.org/manuals/MPI_B51-B52_Product_Manual.pdf
?
Q: Is the 91/92 being asked about merely a 96TPI version of the MPI
B51/B52?
The QT Systems ad in Infoworld that Google comes up with as an early
hit says 77 track (not 80). It correctly refers to the B51 as "Sgl
sided, Sgl/Dbl Den", but refers to the B52 as "Sgl Sided, Dbl Den",
rather than double sided single/double density.
So, although 77 V 80 tracks is a definite possibility in those days,
the reliability of the specs in that ad are questionable.
The B51 was the first non-SHugart 5.25" drive that I ever had.
substituting it for the SA400 was truly trivial.
Motor speed seemed to wander a bit, but the track alignment held more
stably than the SA400.
--
Grumpy Ol' Fred ci...@xenosoft.com
