19 Oct
1999
19 Oct
'99
8 a.m.
On Tue, 19 Oct 1999, Fred Cisin (XenoSoft) wrote:
By the way, in my earlier remarks about the 100 tpi Tandon drive, I
alleged that it was a TM100-4A. WRONG! It is a TM100-4R. Guess I
need new glasses :)
- don
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.
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.
Disk Rotational Speed 300 RPM +/- 1.5%
Motor Start Time 250 milliseconds
Motor Stop Time 150 milliseconds
Seek Time,track to track 5 milliseconds
Head Settling Time 15 milliseconds
Ave Track Access Time 75 milliseconds
Typ. Recording Modes FM,MFM,MMFM
Data Transfer Rate 250,000 bits per second
"Data Transfer Rate" is not a meaningful spec in this context!
Particularly following the acknowledgement that the drive was suitable for
recording modes besides MFM!
Unformated Cap. TM100-1 250Kb per disk,
TM100-2 500Kb per disk
"Unformatted Cap." is assumed to be MFM.
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.
--
Grumpy Ol' Fred cisin(a)xenosoft.com