8" 96-tpi drives

[mgarlanger]

Are there 8" 96-tpi drives? I came across an announcement for a disk device driver that mentioned 8" 96-tpi drives were due out later that year (1982):

#: 41869 Sec. 5
Sb: HDOS for CDR FDC-880H
16-Oct-82 19:07:08
Fm: Ray Livingston 70105,1207
To: ALL

To ALL CDR USERS -
The HDOS Device Driver for the CDR FDC-880H Double Density Disk
Controller has been shipping for over a month, and the response has been
tremendous! In case you haven't heard about it, this driver supports ALL
H/Z-37 AND H/Z-47 disk formats and is completely HDOS compatible. It is also
VERY fast. (MBASIC loads in under 1.5 seconds!) In addition, it supports the
96tpi 8" drives due out later this year for up to 2 Megabytes per disk! It
also provides detailed error histories for each drive, allowing the user to
spot a failing drive before it fails completely.
This driver is available for $40 plus $2 shipping from:
Livingston Logic Labs
Post Office Box 5334
Pasadena, California 91107
In a few months, we will also be releasing Heath CP/M 2.2.03 modified
for use with the CDR FDC-880H. This will contain ALL features of the Heath
CP/M, and be completely compatible with ALL H/Z-37 and H/Z-47 disk formats,
including extended double density, etc. This will also support 96 tpi 8"
drives when they come out.
Both of the above products will operate at ANY CPU speed up to 4 Mhz
with NO patching.

 

[Chuck(G)]

There was one short-lived version offered by Hitachi; I'm not aware of it making any market headway. Herb Johnson tells the story:

8-inch HD high-density diskettes

I've never run into the media, personally.

 

[krebizfan]

Maybe? There was an announcement for some models. The Hitachi model was the FD-441 with a capacity of 9.6 MB. The Elcomatic model was ACP 1500 with a capacity of 3.2 MB. From Disk Trends 1985 which means what was produced in 1984

In 1983, Hitachi announced a half-high drive with 9.6 mega-
bytes capacity, achieved with 96 TPI and 20,560 BPI, using a run length
limited code, with cobalt modified oxide coated media.
Elcomatic's ACP
1500 provides 3.2 megabytes by using 96 TPI and normal recording den-
sities.

Note that either way, those drives were uncommon. Hitachi only made 95,000 8" drives and Elcomatic's drives had to fit in the category of other with a total 38,000 8" drives between all the small manufacturers. Those figures include a lot of normal drives.

 

[Al Kossow]

I just dug these up for someone on the Applesauce Discord

 

[mgarlanger]

Yes, that was me too on discord. I asked in a few spots for a better chance to find someone that knew. At least this one has a better chance of google indexing it. My initial google search didn't turn up anything. Thanks.

 

[Chuck(G)]

Given the weird characteristics of the Hitachi unit ( (2,7) RLL encoding), I think that Herb has it right--driven by the hard disk controller and probably captive to that hard disk unit.
There were a few FDC/HDC chips that could handle either (e.g. HDC 9234, SMC's "Universal DIsk Controller").

 

[Eudimorphodon]

It was the Kaypro Robie that had those weird 2.6MB 192 TPI 5.25" floppy drives, right? That thing was such a roaring success I'd say Kaypro totally missed the boat by not making a jumbo model with these Hitachi 8" drives and a 19" CRT. I mean, who wouldn't want an 18" square black metal cube sitting on their desk?

 

[krebizfan]

The Elcomatic drives were the ones I would have expected to succeed. Slap the 80 track 5.25" heads into an 8" drive. Spend a few hours fixing any problems with the heads moving. Double the capacity for the same price. There wasn't much compatibility between 8" formats anyway so a little more incompatibility won't matter.

 

[Chuck(G)]

It was the Kaypro Robie that had those weird 2.6MB 192 TPI 5.25" floppy drives, right? That thing was such a roaring success I'd say Kaypro totally missed the boat by not making a jumbo model with these Hitachi 8" drives and a 19" CRT. I mean, who wouldn't want an 18" square black metal cube sitting on their desk?

Yup, the Drivetec, later Kodak (after Drivetec's bankruptcy). The positioner was pretty clever--two steppers connected by a lever arm. One stepper for coarse, the other for fine seeking. What tanked the thing was the requirement for expensive factory-formatted floppies (it used an embedded servo scheme). Had the thing been able to take plain old 1.2MB or 360KB floppies and format them to 2.88MB (or later 6MB), it might have had a chance. Disk spins at 600 RPM, so reading normal floppies on one is pretty fast.

I wonder how well the Hitachi RLL scheme worked out. Generally, the more aggressive the encoding algorithm, the less tolerance for jitter and ISV, not to mention the particle size of the medium. That's why FM is generally more reliable than MFM. Group code takes it to another level.

 

[mgarlanger]

The Elcomatic drives were the ones I would have expected to succeed. Slap the 80 track 5.25" heads into an 8" drive. Spend a few hours fixing any problems with the heads moving. Double the capacity for the same price. There wasn't much compatibility between 8" formats anyway so a little more incompatibility won't matter.

I think the 8" form factor was just to unwieldy once people got used to the smaller 5.25" or 3.5" disks.