23 Aug
2018
23 Aug
'18
11:43 a.m.
Well it all depends upon what u mean by "first"
The Sony drive and cartridge were not compatible in many ways with what
became the physical, magnetic and electrical interface standards for the
3.5-inch drive and cartridge. The standards came out of the "Microfloppy
Industry Committee" (Google it with quotes) organized by Shugart Corp.
Either Shugart or Tandon was the first to ship drives compatible to the
standard. Tandon probably did the first such cartridge.
The original Sony drive and cartridge died out and Sony didn't come out with
a compatible set until well after Shugart and Tandon. The early adopters of
the Sony design like HP then changed to the industry standard design.
Tom
-----Original Message-----
From: Fred Cisin [mailto:cisin at xenosoft.com]
Sent: Wednesday, August 22, 2018 1:25 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: Prototype IBM DemiDiskette drive
> I just picked up a Model 350 on eBay, just because
I'd never seen a
> Shugart sub 5" drive.
> https://www.ebay.com/itm/Vintage-Sankyo-Shugart-Venture-Model-350-
> Computer-Disk-Drive-/253708808435
On Wed, 22 Aug 2018, Ali via cctalk wrote:
Interesting. I wonder if IBM was looking at those
drives for use. The
seller (or more accurately the seller's father) used to work
for IBM
Industrial services in Boca Raton.
Well, the SA300 (single sided version) were not the first 3.5" drives, but
they may have been the first 300 RPM ones with an SA400 interface.
(The Sony 600RPM drives would require more changes)
The SA300 could be dropped into a 5150 (with only issues of mounting
brackets (Erector set) and power connector) and were supported by some OEM
versions of MS-DOS 2.11. IBM public support of 3.5" began with PC-DOS 3.20.
23 Aug
23 Aug
12:19 p.m.
On 08/23/2018 11:43 AM, Tom Gardner via cctalk wrote:
Well it all depends upon what u mean by
"first"
The Sony drive and cartridge were not compatible in many ways with what
became the physical, magnetic and electrical interface standards for the
3.5-inch drive and cartridge. The standards came out of the "Microfloppy
Industry Committee" (Google it with quotes) organized by Shugart Corp.
Either Shugart or Tandon was the first to ship drives compatible to the
standard. Tandon probably did the first such cartridge.
I must confess some bewilderment. Around 1981, I did some contract
work for an outfit called Preis for their portable computer. I don't
recall the nature of the work anymore, but I still have a copy of their
BIOS for CP/M.
At any rate, the thing used the Sony 0A-D30 single-sided 600 RPM
floppies, which held about half as much as the corresponding 8" media
(in FM, about 160KB). The major differences were that the Sony drive
could access only 70 cylinders, while the 8" drives could do 77. In
addition, the Sony spun at 600 RPM, which allowed for the use of an 8"
drive interface, albeit at a reduced track capacity over the 8" drive.
One other notable aspect was that the Sony's 26-pin interface had no
motor control line--the disk spun continuously, just like its 8"
relatives. Similarly, it had a head-load solenoid, just like the 8"
drives.
Media-wise, I believe there was little difference between the Sony
floppies and more modern DS2D commodity media. I believe the disk
shutters were not sprung, but were manual.
I used to have a couple of these drives, but scrapped them because the
modern slow 3.5" drives did a better job of handling floppies.
Where Shugart fits into all of this, I have no idea.
--Chuck
24 Aug
24 Aug
12:50 p.m.
As Chuck notes the shutter closing was different, the RPM was different and the interface
was quite different. Also different was the media coercivity, media thickness, data rate
and physical drive form factor. Enough differences such that the Sony 0A-D30 drive and
medium could not interchange with what became the industry standard for 3? FDDs and FDs.
What became the standard in all these areas and others was defined by the
"Microfloppy Industry Committee" which was formed and led by folks from Shugart
Corp. At its peak it had at least 23 members. In January 1983 Sony agreed to supply
media comporting to the MIC standard. Both Tandon and Shugart showed drives at Comdex
1982; who shipped first in 1983 is unknown.
Tom
-----Original Message-----
From: Chuck Guzis [mailto:cclist at sydex.com]
Sent: Thursday, August 23, 2018 12:20 PM
To: Tom Gardner via cctalk
Subject: Re: First 3.5 inch FDD [WAS: RE: Prototype IBM DemiDiskette drive]
On 08/23/2018 11:43 AM, Tom Gardner via cctalk wrote:
Well it all depends upon what u mean by
"first"
The Sony drive and cartridge were not compatible in many ways with
what became the physical, magnetic and electrical interface standards
for the 3.5-inch drive and cartridge. The standards came out of the
"Microfloppy Industry Committee" (Google it with quotes) organized by Shugart
Corp.
Either Shugart or Tandon was the first to ship drives compatible to
the standard. Tandon probably did the first such cartridge.
I must confess some bewilderment. Around 1981, I did some contract
work for an outfit called Preis for their portable computer. I don't recall the
nature of the work anymore, but I still have a copy of their BIOS for CP/M.
At any rate, the thing used the Sony 0A-D30 single-sided 600 RPM floppies, which held
about half as much as the corresponding 8" media (in FM, about 160KB). The major
differences were that the Sony drive could access only 70 cylinders, while the 8"
drives could do 77. In addition, the Sony spun at 600 RPM, which allowed for the use of
an 8"
drive interface, albeit at a reduced track capacity over the 8" drive.
One other notable aspect was that the Sony's 26-pin interface had no motor control
line--the disk spun continuously, just like its 8"
relatives. Similarly, it had a head-load solenoid, just like the 8"
drives.
Media-wise, I believe there was little difference between the Sony floppies and more
modern DS2D commodity media. I believe the disk shutters were not sprung, but were
manual.
I used to have a couple of these drives, but scrapped them because the modern slow
3.5" drives did a better job of handling floppies.
Where Shugart fits into all of this, I have no idea.
--Chuck
2:38 p.m.
On Fri, 24 Aug 2018, Tom Gardner via cctalk wrote:
As Chuck notes the shutter closing was different, the
RPM was different
and the interface was quite different. Also different was the media
coercivity, media thickness, data rate and physical drive form factor.
Enough differences such that the Sony 0A-D30 drive and medium could not
interchange with what became the industry standard for 3? FDDs and FDs.
What became the standard in all these areas and others was defined by
the "Microfloppy Industry Committee" which was formed and led by folks
from Shugart Corp. At its peak it had at least 23 members. In January
1983 Sony agreed to supply media comporting to the MIC standard. Both
Tandon and Shugart showed drives at Comdex 1982; who shipped first in
1983 is unknown.
THANK YOU for all of the details!
As to the shutter:
There were early diskettes with NO shutter. I have one with a "Shugart"
label. It's POSSIBLE that it was only a prototype?
There were some with completely manual shutters.
There were "Pinch" diskettes. You manually opened the shutter against
minor spring tension, and it latched. To close it, you pinched the corner
of the housing, and the spring closed the shutter. There was a word
"Pinch" imprinted in the corner, and an arrow pointing to it. I had most
of a box of new HP ones of those at VCF. A guy scammed the consignment
staff into letting him walk away with the whole box at the "price per
ONE disk" price.
Then came the completely automatic diskettes that everybody is faamiliar
with. They stopped imprinting the word "Pinch", but they left the arrow!
(under the premise that "it shows which way to put the disk into the
drive")
I used no shutter diskettes, manual shutter diskettes, "pinch" diskettes,
and automatic shutter diskettes in Shugart SA300 automatic shutter drives.
You had to be a little careful of the shutter in the early drives.
If there were differences in the media coercivity or media thickness,
they were minor enough to not prevent my using the wrong ones.
Do people using the Sony drives have difficulty using the other diskettes?
This, of course, is NOT the same issue as the differences between
"720K/800K" diskettes V "1.4M"/"HD".
The "720K/800K" were about 600 Oersted, and
"1.4M"/"HD" is somewhere
around 720 to 750 Oersted. Unlike "360K" V "1.2M" (300 Oersted V 600
Oersted), the difference between the 3.5" diskettes is close enough thet
many people are not aware of it, and misuse a good 3.5" diskette as a
mediocre one in the wrong drive.
"1.4M"/"HD" diskettes have an extra hole identifying the media;
some
drives have sensors looking for that; some (including many PS/2) don't.
"ED"/"2.8M" has a different material for the cookie
(Barium-ferrite),
and a slightly different media ID hole.
Drive form factor was not much of an issue - to retrofit a 3.5" drive into
a PC, you had to make your own mounting brackets anyway (Erector Set).
Soon, there became available trays to put a 3.5" drive into a half-height
5.25" bay.
RPM, Data transfer rate is a minor issue.
The 600RPM of the Sony drive requires a 500,000 bits per second data
transfer rate (like an 8" or "1.2M")
Another variant to be aware of:
NEC has 3.5" drives that are 360RPM (like an 8" floppy), instead of
300RPM. That lets them have the same structures on the diskette for 8",
5.25" "1.2M", and their 3.5" format. (77? track, 8 sector, 1024 bytes
per sector) Those drives are sometimes referred to as "Type 3" or "3
Mode",
Some OEMs used 3.5" with CP/M.
Some OEMs modified MS-DOS to support 3.5"
MS-DOS 2.11 made that much easier than it had been with previous versions.
PC-DOS 3.20 was the first official support of 3.5" from IBM.
PC-DOS 3.30 was the first official support of "1.4M" from IBM.
MS-DOS 3.31 was, like 2.11, often customized, including HDD larger than
32M. etc.
As to "FIRST". . . .
The word should be avoided in all historical research.
Few are willing to acknowledge the possibility of a "tie".
But, often one company is the first to announce, another is first to have
a working prototype, another is first to demo, another is first to start
taking orders, another is first to ship their first one, another is first
to be able to supply without long pre-order, another . . .
Apple/TRS80/PET had overlaps of which phase of being first each one was.
And, LITTLE guys are ignored when a BIGGIE comes out with the same thing.
E.g., Osborne was most definitely NOT the first to come out with a "sewing
machine"/"suitcase" computer. In fact, right across the aisle from the
many thousands of dollars of chrome and black plexiglass of his big
announcement, Elcompco (in a corner of the Berkeley Microcomputer/XenoSoft
booth) was fulfilling orders for a machine with floppy drives and 5"
monitor built into a Halliburton attache case.
So, for my PERSONAL meaning of "first", Shugart SA300 was the first 3.5"
drive with "standard" interface that I could buy at a computer swap and
carry home.
--
Grumpy Ol' Fred cisin at xenosoft.com
23 Aug
23 Aug
12:37 p.m.
On Thu, Aug 23, 2018 at 12:43 PM, Tom Gardner via cctalk <
cctalk at classiccmp.org> wrote:
Well it all depends upon what u mean by
"first"
The Sony drive and cartridge were not compatible in many ways with what
became the physical, magnetic and electrical interface standards for the
3.5-inch drive and cartridge. The standards came out of the "Microfloppy
Industry Committee" (Google it with quotes) organized by Shugart Corp.
Either Shugart or Tandon was the first to ship drives compatible to the
standard. Tandon probably did the first such cartridge.
The original Sony drive and cartridge died out and Sony didn't come out
with
a compatible set until well after Shugart and Tandon. The early adopters
of
the Sony design like HP then changed to the industry standard design.
AFAICT, the only difference was that the pre-standard Sony 3.5-inch
diskettes had a manually operated shutter. The manual shutter and automatic
shutter 3.5-inch diskettes are interchangeable with some care.
For a while, diskettes were sold that had the automatic shutter, but also
had a way the user could latch the shutter open, so that they could be used
in early drives that didn't have the pin to open the automatic shutter.
I only ever saw the manual-shutter drives in Sony and HP equipment, though
I wouldn't be surprised if there were some other uses.
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cclist＠sydex.com -
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