20 Sep
2002
20 Sep
'02
3:30 a.m.
I was scrounging around last week and found a pair of HH 5 1/4" floppy drives that
are marked "2.4" next to a disk symbol on the front. Just out of curiousity I
picked them up and checked <http://marina.mfarris.com/floppy/Hitachi.html> and sure
enough they're 2.4Mb floppy drives! I've never heard of these before. Does anyone
know what the disk format is or where these are used? The drives are Hitachi model
FD532EIU. The label on them says that they're made for IBM. They're in some sort
of a plastic sled.
Joe
20 Sep
20 Sep
5:45 a.m.
On Fri, 20 Sep 2002, Joe wrote:
I was scrounging around last week and found a pair
of HH 5 1/4"
floppy drives that are marked "2.4" next to a disk symbol on the
front. Just out of curiousity I picked them up and checked
<http://marina.mfarris.com/floppy/Hitachi.html> and sure enough
Interesting that those guys refer to them as "high density", but refer to
the 1.2M as "double density"
they're 2.4Mb floppy drives! I've never heard
of these before. Does
anyone know what the disk format is or where these are used? The
drives are Hitachi model FD532EIU. The label on them says that they're
made for IBM. They're in some sort of a plastic sled.
I'm not familiar with them, at all. I don't think that IBM ever
released a machine with them, like their 3.9" drive. It does not appear
to be supported in any version of PC-DOS. But a simple block mode device
driver is all that would be needed.
There have been a few different higher density 5.25" systems, such as the
one that Kodak bought out. But I don't think that this is the same one.
There are two obvious ways to get that capacity. One would be to halve
the track spacing to 192 TPI. That would give you 160 tracks per side,
with 15 sectors per track with 512 bytes per sector, and would permit
using "regular" 600 Oerstedt ("1.2M") diskettes, but possibly with
some
problems with diskettes that aren't quite up to it. (like the problems
that Tony has with using "360K" diskettes for 720K 5.25.) It would
require a smaller step track to track, and a narrower head (about 1/2 mm
wide track v the 1/6mm wide track of the 1.2M)
The other way to do it would be to use a barium ferrite diskette (5.25
version of the 2.8M 3.5"). That would require a special head for
"vertical recording", and would require a 1000K bits per second data
transfer rate (same as for the 2.8M 3.5"). Then it would still only be 80
tracks per side, but instead of 15 512 byte sectors, it would be able to
fit 30 (or maybe even 32) 512 byte sectors on each track.
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
PO Box 1236 (510) 558-9366
Berkeley, CA 94701-1236
24 Sep
24 Sep
6:20 a.m.
New subject: Pictures Re: 2.4Mb 5 1/4" floppy drive?
I'm still trying to find out where the 2.4Mb 5 1/4" floppy drives came from. I
finally got around to taking some pictures of the 2.4Mb floppy drive. This one
<http://home.cfl.rr.com/rigdon14/hit2_4/front.jpg> is a picture of the front. This
one <http://home.cfl.rr.com/rigdon14/hit2_4/sled.jpg> is a picture of the plastic
sled that it's mounted in. This
<http://home.cfl.rr.com/rigdon14/hit2_4/back.jpg> is a picture of the back showing
the Hitachi label and the connector that plugs into the system. This
<http://home.cfl.rr.com/rigdon14/hit2_4/top.jpg> is a picture of the top of the bare
drive. And here <http://home.cfl.rr.com/rigdon14/hit2_4/bottom.jpg> is a picture of
the bottom. The sled has IBM PN 25F8398 on it. I've searched Google and IBM's
site for the number but didn't find anything. I found these drives in the same pile
with some IBM RS/6000 cards. Does anyone know if the RS/6000 uses anything like this?
Joe
10:10 a.m.
New subject: Pictures Re: 2.4Mb 5 1/4" floppy drive?
On Tue, 24 Sep 2002, Joe wrote:
I'm still trying to find out where the 2.4Mb 5
1/4" floppy drives
came from. I finally got around to taking some pictures of the 2.4Mb
floppy drive. This one
<http://home.cfl.rr.com/rigdon14/hit2_4/front.jpg> is a picture of the
front. This one <http://home.cfl.rr.com/rigdon14/hit2_4/sled.jpg> is a
picture of the plastic sled that it's mounted in. This
<http://home.cfl.rr.com/rigdon14/hit2_4/back.jpg> is a picture of the
back showing the Hitachi label and the connector that plugs into the
system. This <http://home.cfl.rr.com/rigdon14/hit2_4/top.jpg> is a
picture of the top of the bare drive. And here
<http://home.cfl.rr.com/rigdon14/hit2_4/bottom.jpg> is a picture of the
bottom. The sled has IBM PN 25F8398 on it. I've searched Google and
IBM's site for the number but didn't find anything. I found these drives
in the same pile with some IBM RS/6000 cards. Does anyone know if the
RS/6000 uses anything like this?
This does look like the drive from a 3174 Controller that someone else
mentioned.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
20 Sep
20 Sep
8:33 a.m.
On Fri, 20 Sep 2002, Joe wrote:
I was scrounging around last week and found a pair
of HH 5 1/4"
floppy drives that are marked "2.4" next to a disk symbol on the
front. Just out of curiousity I picked them up and checked
<http://marina.mfarris.com/floppy/Hitachi.html> and sure enough
they're 2.4Mb floppy drives! I've never heard of these before. Does
anyone know what the disk format is or where these are used? The
drives are Hitachi model FD532EIU. The label on them says that they're
made for IBM. They're in some sort of a plastic sled.
Do these drives have the typical single stepper to position the heads,
Joe, or is there an additional "vernier stepper" to more closely
position them as was the case with the Drivetec and (later) Kodak
drives? Both of those required preformatted disks that contained servo
tracks.
- don
24 Sep
24 Sep
6:30 a.m.
At 01:34 PM 9/20/02 -0700, Don wrote:
On Fri, 20 Sep 2002, Joe wrote:
Don,
No it's looks like just a single stepper motor. I found a diskette in one of htem.
It appears to be a standard disk. More about that in reponse to Will's message.
Joe
I was scrounging around last week and found a
pair of HH 5 1/4"
floppy drives that are marked "2.4" next to a disk symbol on the
front. Just out of curiousity I picked them up and checked
<http://marina.mfarris.com/floppy/Hitachi.html> and sure enough
they're 2.4Mb floppy drives! I've never heard of these before. Does
anyone know what the disk format is or where these are used? The
drives are Hitachi model FD532EIU. The label on them says that they're
made for IBM. They're in some sort of a plastic sled.
Do these drives have the typical single stepper to position the heads,
Joe, or is there an additional "vernier stepper" to more closely
position them as was the case with the Drivetec and (later) Kodak
drives? Both of those required preformatted disks that contained servo
tracks.
10:41 a.m.
On Tue, 24 Sep 2002, Joe wrote:
No it's looks like just a single stepper motor.
I found a diskette
in one of htem. It appears to be a standard disk. More about that in
reponse to Will's message.
Assuming that it is a formatted, used diskette for that drive, (not just
any-old diskette being used as a shipping head protector), then several
things can be determined from it.
What COLOR is the media? 360K and 1.2M (300 oerstedt v 600 oerstedt) are
slightly different colors. 1.4M floppies v 2.8M (Barium Ferrite) are
different colors.
If the diskette is the same material as a 1.2M, then the 2.4M was probably
achieved by going to 192 TPI, instead of 96 TPI, since that would use the
same oerstedt media as 1.2M.
OTOH, if it is a Barium Ferrite media, then it is probably still 96 TPI,
but with twice the linear density on each track of a 1.2M. That would
require a different media.
Try write protecting the diskette and put it into a DOS machine.
(the error messages from Windoze will hide all useful information)
If it is readable (both DIRectory and files, then it is NOT a 2.4M
diskette
If part of the DIRectory is readable, but file access produces SECTOR NOT
FOUND, or GENERAL FAILURE, or if you ever get SECTOR NOT FOUND, or SEEK
ERROR. then it is almost certainly 192 TPI.
If NOTHING is readable and produces General Failure (even first sectors of
DIRectory - try "ignore"), then it could be either.
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
11:51 a.m.
At 03:42 PM 9/24/02 -0700, Fred wrote:
On Tue, 24 Sep 2002, Joe wrote:
It looks exactly the same color as the Ds, HD, 96 TPI disks that I have and neither of
them have hub reinforment rings. The 360k disks that I have have a greener color.
No it's looks like just a single stepper
motor. I found a diskette
in one of htem. It appears to be a standard disk. More about that in
reponse to Will's message.
Assuming that it is a formatted, used diskette for that drive, (not just
any-old diskette being used as a shipping head protector), then several
things can be determined from it.
What COLOR is the media? 360K and 1.2M (300 oerstedt v 600 oerstedt) are
slightly different colors. 1.4M floppies v 2.8M (Barium Ferrite) are
different colors.
If the diskette is the same material as a 1.2M, then the 2.4M was probably
achieved by going to 192 TPI, instead of 96 TPI, since that would use the
same oerstedt media as 1.2M.
OTOH, if it is a Barium Ferrite media, then it is probably still 96 TPI,
but with twice the linear density on each track of a 1.2M. That would
require a different media.
Try write protecting the diskette and put it into a DOS machine.
(the error messages from Windoze will hide all useful information)
If it is readable (both DIRectory and files, then it is NOT a 2.4M
diskette
If part of the DIRectory is readable, but file access produces SECTOR NOT
FOUND, or GENERAL FAILURE, or if you ever get SECTOR NOT FOUND, or SEEK
ERROR. then it is almost certainly 192 TPI.
If NOTHING is readable and produces General Failure (even first sectors of
DIRectory - try "ignore"), then it could be either.
OK I'll try it when I get a chance. I'm pretty sure that it came from a 3174
and I searched for info on them but couldn't find anything that talked about the disks
or that drive other than mentioning that it was an available option.
Joe
5 p.m.
On Tue, 24 Sep 2002, Joe wrote:
At 03:42 PM 9/24/02 -0700, Fred wrote:
Looked it up in the Pocket PC Ref and found it listed as 2.4MB and DSHD
which would suggest the 192 TPI. You might connect one of the drives to
a PC FDC, stuff a HD floppy in it and issue the format command. If the
head travels only half way before starting the verify pass, it is
certainly the higher track density.
- don
On Tue, 24 Sep 2002, Joe wrote:
It looks exactly the same color as the Ds, HD, 96 TPI disks that I have and neither
of them have hub reinforment rings. The 360k disks that I have have a greener color.
No it's looks like just a single stepper
motor. I found a diskette
in one of htem. It appears to be a standard disk. More about that in
reponse to Will's message.
Assuming that it is a formatted, used diskette for that drive, (not just
any-old diskette being used as a shipping head protector), then several
things can be determined from it.
What COLOR is the media? 360K and 1.2M (300 oerstedt v 600 oerstedt) are
slightly different colors. 1.4M floppies v 2.8M (Barium Ferrite) are
different colors.
If the diskette is the same material as a 1.2M, then the 2.4M was probably
achieved by going to 192 TPI, instead of 96 TPI, since that would use the
same oerstedt media as 1.2M.
OTOH, if it is a Barium Ferrite media, then it is probably still 96 TPI,
but with twice the linear density on each track of a 1.2M. That would
require a different media.
Try write protecting the diskette and put it into a DOS machine.
(the error messages from Windoze will hide all useful information)
If it is readable (both DIRectory and files, then it is NOT a 2.4M
diskette
If part of the DIRectory is readable, but file access produces SECTOR NOT
FOUND, or GENERAL FAILURE, or if you ever get SECTOR NOT FOUND, or SEEK
ERROR. then it is almost certainly 192 TPI.
If NOTHING is readable and produces General Failure (even first sectors of
DIRectory - try "ignore"), then it could be either.
OK I'll try it when I get a chance. I'm pretty sure that it came from a
3174 and I searched for info on them but couldn't find anything that talked about the
disks or that drive other than mentioning that it was an available option.
Joe
8124
days inactive
8129
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8 comments
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cisin＠xenosoft.com -
donm＠cts.com -
foo＠siconic.com -
rigdonj＠cfl.rr.com