28 Apr
2007
28 Apr
'07
10:28 a.m.
Does anyone know if these are 40 or 80 cylinder? Google seems to suggest that
they're 40 (which is what I need). The drives all have little stickers on
saying "Quad density" though (which always implies to me 80-track, but maybe
to Tandon it means 40 track but you have the luxury of two sides :)
cheers
J.
28 Apr
28 Apr
11:55 a.m.
On 28 Apr 2007 at 12:28, Jules Richardson wrote:
Does anyone know if these are 40 or 80 cylinder?
Google seems to suggest that
they're 40 (which is what I need). The drives all have little stickers on
saying "Quad density" though (which always implies to me 80-track, but maybe
to Tandon it means 40 track but you have the luxury of two sides :)
IIRC, the -4A was the 96 tpi version and the -2 was 48 tpi. The -4M
is 100 tpi. I suppose it's possible that someone's replaced the
positioner on these.
Cheers,
Chuck
1:36 p.m.
On Sat, 28 Apr 2007, Jules Richardson wrote:
Does anyone know if these are 40 or 80 cylinder?
Google seems to suggest that
they're 40 (which is what I need).
TM100-2 [with or without A] is 40 cylinder 2
sided; what is commonly being
referred to as "360K". And, in fact, IBM used them.
The drives all have little stickers on
saying "Quad density" though (which always implies to me 80-track, but maybe
to Tandon it means 40 track but you have the luxury of two sides :)
80 cylinder 2 side is TM100-4.
TM100-4M is 100 tpi, insteap of 96tpi.
I don't recall Tandon EVER EVER using the phrase "Quad density".
To most people, "Quad density" means 80 cylinder 2 sides.
BUT, . . .
Intertec (Superbrain) used "double density" to refer to their MFM 1 sided
40 track. When they went to DSDD (40 cylinder 2 side MFM), they called
that "Quad density"! Could those stickers have come from them, or
somebody similar?
And later, when the3y went to 96tpi DSDD (80 cylinder 2 side MFM),
they called that "SUPER density" ("SD"!!!!).
What is the next size of olives?
One MAJOR caveat. When drives were "repaired" by third party board
swappers, they sometimes ended up with the wrong designators.
SO, it COULD BE TM100-4.
I have some 100-4M (Micropolis compatible 100tpi, instead of 96tpi) that
are labelled 100-4, instead of 100-4M.
--
Grumpy Ol' Fred cisin at xenosoft.com
29 Apr
29 Apr
4:24 a.m.
Does anyone know if these are 40 or 80 cylinder? Google seems to suggest that
they're 40 (which is what I need). The drives all have little stickers on
saying "Quad density" though (which always implies to me 80-track, but maybe
to Tandon it means 40 track but you have the luxury of two sides :)
A -2 should be a 40 track (48tpi) drive. The -4 would have been the 80 track
(96tpi) drive - unless it's a -4M which iirc is 100tpi.
If it hasn't fallen off, the Tandon drives have a little sticker up under the
door opener handle - open the doot, then look up from the front bottom of the
drive - inside the handle you may find a sticker reading "48 tpi" or
"96 tpi".
The term "quad density" was used by some people to describe a Double-Sided,
Double-Densoty drive (4 times as much storage as a SSSD drive) - NorthStar
used to describes their DSDD drives as "quad density" even though they were
only 48tpi.
Easy way to tell for sure - hook it up to your imagedisk machine, then gointo
the "Align/test" function and step to track 40 - if the head travels the
whole distance, the drive is 40 track - if it only goes 1/2 way, it's 80
track.
Dave
--
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html
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cclist＠sydex.com -
cisin＠xenosoft.com -
dave06a＠dunfield.com -
julesrichardsonuk＠yahoo.co.uk