15 Dec
2005
15 Dec
'05
6:52 p.m.
Subject: RE: Early 3.5" Floppy Drives
From: Roger Merchberger <zmerch at 30below.com>
Date: Thu, 15 Dec 2005 13:40:44 -0500
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
Rumor has it that Allison may have mentioned these words:
[snippety]
;) it's obsolete. I know there were at least 20 formats not mentioned
that were "out of the mainstream" so more exceptions are known.
However looking at the clock rates mentioned I'd guess it can be done. ;)
Allison
Size density format writeclock
-----------------------------------
8" DD MFM 1000khz
8" SD FM 500khz (8"SSSD 241k CP/M standard)
5.25 DD MFM 500khz (40track is 360k, 80track 720k)
5.25 SD FM 250khz
3.5" HD MFM 1000khz (1.44mb) (looks like 8" different CHS)
3.5" DD MFM 500khz (720k) (same rate as 5.25 DD and 8" SD)
3.5" ?? FM 250khz (not used obsolete)
3.5" FM was used for microcomputers - the Tandy Portable Disk Drive (OEMmed
by Brother, IIRC) was 40 tracks, 2SPT FM w/100K storage. Serial port
driven, and worked with the Tandy Model 100/102/200 laptops. In my Service
manual for the critter, it did mention the density, but I don't have that
handy. DD disks worked just fine on it (read: data life at least into the
10 year range), but HD didn't work so well, IIRC.
The TPDD2 was also FM, but used an 80 track drive (set into 2 banks for
compatibility with the TPDD1) for 200K storage.
Laterz,
Roger "Merch" Merchberger 
15 Dec
15 Dec
7:19 p.m.
Rumor has it that Allison may have mentioned these words:
From: Roger Merchberger <zmerch at 30below.com>
<MODE="SnobbishBastageButJustJoking">
And 8" drives aren't obsolete??? :-O
</MODE>
By today's definition, they're *all* obsolete... ;-) I was responding to
the "not used" part - I'd read that as "no major manufacturer actually
used
that format." I obviously interpreted that incorrectly, but 3.5" FM drives
are quite a bit easier to find than 2" MFM drives... (Of which I have 2 as
well, and 4 or 5 boxes of media, 2 still shrink-wrapped. :-)
Laterz,
Roger "Merch" Merchberger
--
Roger "Merch" Merchberger -- SysAdmin, Iceberg Computers
zmerch at 30below.com
Hi! I am a .signature virus. Copy me into your .signature to join in!
Rumor has it that Allison may have mentioned these
words:
[snippety]
;) it's obsolete. Size density format writeclock
-----------------------------------
8" DD MFM 1000khz
8" SD FM 500khz (8"SSSD 241k CP/M standard)
5.25 DD MFM 500khz (40track is 360k, 80track 720k)
5.25 SD FM 250khz
3.5" HD MFM 1000khz (1.44mb) (looks like 8" different CHS)
3.5" DD MFM 500khz (720k) (same rate as 5.25 DD and 8" SD)
3.5" ?? FM 250khz (not used obsolete)
3.5" FM was used for microcomputers - the Tandy Portable Disk Drive (OEMmed
by Brother, IIRC) was 40 tracks, 2SPT FM w/100K storage. Serial port
driven, and worked with the Tandy Model 100/102/200 laptops. In my Service
manual for the critter, it did mention the density, but I don't have that
handy. DD disks worked just fine on it (read: data life at least into the
10 year range), but HD didn't work so well, IIRC.
The TPDD2 was also FM, but used an 80 track drive (set into 2 banks for
compatibility with the TPDD1) for 200K storage.
6964
days inactive
6964
days old
1 comments
2 participants
participants (2)
-
ajp166＠bellatlantic.net -
zmerch＠30below.com