[Coco] Trouble with OmniFlop

Gene Heskett gene.heskett at verizon.net
Mon May 29 01:59:13 EDT 2006

Alex Evans wrote:
> On May 28, 2006, at 5:17 PM, Gene Heskett wrote:
>> Alex Evans wrote:
>>> On May 28, 2006, at 10:21 AM, Mike Pepe wrote:
>>>> 3.5" disks are 96tpi regardless of their capacity. 5.25" disks are 
>>>> 48tpi if the 40 track variety, 96tpi if the 80 track variety.
>>> Actually most 3.5" floppies are 192tpi, though I do have a 40 track 
>>> 3.5" floppy drive which is 96tpi.
>> wrong...
>> In fact, all 3.5" floppy drives are 135tpi, even the oddball variable 
>> speed drives some macs used in times past.  The difference is that 
>> drivers wrongly assume they have to double step some drives.  This is 
>> generally a symptom of the descriptor for that drive being 
>> miss-configured.  If that particular drive software actually uses a 
>> descriptor, rsdos and most of its ilk do not.
> Sorry, but what about a very strange 40 track HP 3.5" floppy drive that 
> I have?  I am pretty sure that it has the track spaced farther apart 
> rather than using only the first 40 tracks.
IMO, the design of a new motor with a coarser track spacing for a floppy 
drive would be something that, generally speaking, would get nixed by 
the bean counters, who would look at that expense, compare it to buying 
a perfectly good std 135 tpi floppy from a Hong Kong supplier for $1.43 
USD each in 10k quantities and make the obvious decision.  Such a thing 
might get by if the idea was to create a totally incompatible disk such 
that all the games or other software would have to be obtained from a 
single source, that maker.  And thats been tried, and found wanting in 
every case I've heard of.  In eprom packaging for game machines that 
packaging for incompatibility seems to work, but not in floppy's.

OTOH, every new class of MBA's has got to learn that lesson all over 
again, so I know better than to call it impossible.  Like the QueCat, 
most such bits of hardware are now consigned to the bins of history, but 
like mine, saved on the basis of maybe finding something it might be 
useful for, someday...

Cheers, Gene

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