19 Oct
1999
19 Oct
'99
9:55 a.m.
According to my Tandon OEM Operating and Service
Manual
for the TM100-1 and TM100-2:
Tracks per inch 48 TPI both drives
Tracks per drive TM100-1 40 tracks, TM100-2 80 tracks
While
"CORRECT" in some twisted perverted way, that is VERY misleading. No, it's correct. Not only in some 'twisted
perverted way'.
The TM100-2 has 40 cylinders. Each contains 2 tracks (one on each side of
the disk). That's 80 tracks total.
And yes, this does mean that a PC 3.5" drive has 160 tracks (in 80
cylinders). I've seen that mentioned in manuals before as well....
While perhaps my use opf "twisted or perverted" may be bothersome, you
surely would not disagree that some people [incorrectly] refer to the
100-4 and 1.2M drives as an "80 track" drive. And you certainly won't
disagree that use of the word "cylinder" completely avoids the entire
ambiguity. Tandon does not appear to have EVER used the term "cylinder".
Perhaps some other flopy companies may have, but I can [unfortunately]
only seem to find it used by hard-drive companies.
If they HAD used "cylinders", then we wouldnb't be having this discussion.
In MICROCOMPUTERS, rather than DEC iron, SS v DS typically preceded 40T^H
Cylinder v 80 T^H Cylinder. Therefore, in SOME circles, "TRACK" was used
to refer to "tracks per side" rather than TOTAL tracks, just as
"Sectors"
meant "sectors per track" rather than TOTAL sectors.
Many folks reading that would misinterpret it as
implying 80 tracks per
side (aka 96TPI), which it ISN'T. The -2 is the double sided version of
the -1. It is 40 tracks per side. Perhaps it's time to do as the
hard-drive manufacturers did and change the terminology. Both the -1 and
-2 are 40 CYLINDER.
The term 'cylinder' applies to floppy drives and hard
drives AFAIK. BTW, the IBM
"Hardware Maintenance and Service" manuals for the PC and XT
have a lot of pretty pictures of mechanical disassembly of Tandon TM 100-2
drives.
Amazing!. The PC/AT one simply shows you how to replace the entire
(half-height) drives in that machine.
But the O&A Techref does contain several versions of the schematic for
these units.