[Coco] Fw: Help floppy drive

[Roger Merchberger]

Rumor has it that Frank Pittel may have mentioned these words:
>Was there ever a 720K 5.25 floppy drive?

Many! One computer (of many) that shipped with them standard would the 
Tandy 2000 series computers.... sometimes they're (erroneously) refered to 
as "quad density" - erroneously because density generally refers to the 
#/size of bits & sectors per track - and 720K drives were stored the same 
amount of data per track as 360K drives, but had double the # of tracks.

>  I rember the sizes being 360K and 1.2M.

Then you're forgetting 160K (similar to when the CoCo drives first came 
out), 180k, 320k (double-sided but only 35 track), 360K (80-track but only 
single-sided), 720K... and prolly a couple others that I forgot!

>  The 3.5 floppies were 720K and 1.4M.

Ah... not quite. "Normal" MFM 3.5" floppy drives are electrically similar 
to their 5.25" counterparts, and can be used in all the configurations 
listed above - that said, I don't believe there were any 35-track 3.5" 
drives made, but there certainly were 40-track 3.5" drives available, and 
the TPDD (Tandy Portable Disk Drive) for the Model 100/102/200 series (and 
Brother sewing machines, believe it or not) were available in 100K and 200K 
versions as well, but they only used FM encoding (single-density). Those 
were 40 & 80 track respectively; 2 sectors per track.

AFAIK, 2" floppies only came in 720K versions (DSDD 80track). I have a 
Zenith MiniSport laptop that uses them, with 4 boxes of yet unopened media. 
I've always wanted to hack one of those drives into one of my CoCos!

There's also been 2.8" & 3.0" micro-diskette sizes, and don't even get me 
started on the 8" drives... Altho I have a box of those, I've never had a 
computer that uses them.

All in all, *lots* of different rascals over the years.

--
Roger "Merch" Merchberger   | "Profile, don't speculate."
SysAdmin, Iceberg Computers |     Daniel J. Bernstein
zmerch at 30below.com          |