Fred Cisin cisin at
Wed Aug 25 15:57:02 CDT 2021

On Wed, 25 Aug 2021, Jay Jaeger via cctalk wrote:
> I don't have that code, however a couple of points:
> First of all, I think Vector Graphic actually used Micropolis drives (and I 
> suspect yours are because of the hard sectoring).  I have Micropolis drives 
> on my Altair.  Back in 2006 I imaged my floppies - by reading the sectors on 
> my Altair and transferring the data over to my PC and saving an image file.
> Note that at least for the 100 TPI Mod II model you'd have to use an actual 
> Micropolis drive or the tracks won't line up.  I don't know if that is also 
> true of the Mod I drives which have a more standard tracks per inch.

Important points!
Yes, Vector Graphics was 100tpi.  That was not the only unusual aspect to 
their format.

Yes, Micropolis ALSO made 48tpi single sided drives.  I don't remember 
whether they were 35 track or 40 track; I used one for years on a TRS80 
(which wass 35 track); it was an exceptionally reliable, albeit heavy and 
slow-steppping drive.

For 100tpi, there also existed Tandon TM100-4M drives.  The M stood for 
"Micropolis".   One of the TM100-4M drives that I had did not have the 'M' 
on the label.

Grumpy Ol' Fred     		cisin at

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