2 Sep
2022
2 Sep
'22
11:15 a.m.
Im working on an update to Wikipedia on floppy disk drive controllers
there is a nice section on WD but nothing on Intel/NEC
Anyone know the history of how the NEC µPD765 and the Intel 8272 became
compatible devices?
AFAICT it was IBM's August 1981 adoption of the NEC µPD765 in the PC that
drove the industry to standardize on the device.
The earliest dates I can find for the two devices are:
Jan 1981
8272 listed in Intel catalog (not in 1979 catalog)
1979
µPD765 listed in NEC catalog
<http://www.bitsavers.org/components/nec/_dataBooks/1979_NEC_Microcomputer_C
atalog.pdf>
Dec 1978
µPD765 Data Sheet
<http://www.bitsavers.org/components/nec/_dataSheets/uPD765_Data_Sheet_Dec78
.pdf>
As described in the 1978 data sheet the NEC device was 8-inch FD compatible
and of course the PC used 5¼-inch drives but I suspect the differences could
be worked around
It may well be that they were compatible in previous versions (µPD372 and
8271)
Any recollections and links would be appreciated
Tom
2 Sep
2 Sep
11:59 a.m.
On 9/2/22 11:15, Tom Gardner via cctalk wrote:
I’m working on an update to Wikipedia on floppy disk
drive controllers –
there is a nice section on WD but nothing on Intel/NEC
Anyone know the history of how the NEC µPD765 and the Intel 8272 became
compatible devices?
The 8272/µPD765 as well as the graphics controllers (µPD7220: Intel
82720) were the result of a cross-licensing deal between NEC and Intel.
Both were essentially NEC designs. The 765 is described in detail in
the 1980 NEC catalog:
http://blog.kevtris.org/blogfiles/Handhelds/Datasheets/1980%20NEC%20Catalog…
The 7220 came a bit later. The Intel FDC that preceded the 8272, the
8271 was single-density only and doesn't resemble the 8272 at all.
It's obvious from the abovementioned NEC catalog that the extent of
licensing peripheral chips from Intel was pretty broad. The whole
affair continued peacefully until the V20, where Intel sued NEC for
pirating the 8086 microcode, which is an interesting read all by itself.
--Chuck
3 Sep
3 Sep
2:07 a.m.
On 9/2/22 11:59, Chuck Guzis via cctalk wrote:
On 9/2/22 11:15, Tom Gardner via cctalk wrote:
I hope you get information on Don Tarbell's work included. He had an
early single density controller. Then later a high (double) density
controller.
He of course had huge success with his tape reader design, and was
following his interests in storage.
I wish I had good references if they aren't already on Wiki or
elsewhere, only my recollections. I knew him and his manufacturing
friend, Don Culbertson, who did a lot of his manufacturing. But don't
have anything up to wiki requirements for citation.
thanks
Jim
I’m working on an update to Wikipedia on floppy
disk drive controllers –
there is a nice section on WD but nothing on Intel/NEC
Anyone know the history of how the NEC µPD765 and the Intel 8272 became
compatible devices?
The 8272/µPD765 as well as the graphics controllers (µPD7220: Intel
82720) were the result of a cross-licensing deal between NEC and Intel.
Both were essentially NEC designs. The 765 is described in detail in
the 1980 NEC catalog:
http://blog.kevtris.org/blogfiles/Handhelds/Datasheets/1980%20NEC%20Catalog…
The 7220 came a bit later. The Intel FDC that preceded the 8272, the
8271 was single-density only and doesn't resemble the 8272 at all.
It's obvious from the abovementioned NEC catalog that the extent of
licensing peripheral chips from Intel was pretty broad. The whole
affair continued peacefully until the V20, where Intel sued NEC for
pirating the 8086 microcode, which is an interesting read all by itself.
--Chuck
8:47 a.m.
On 9/3/22 02:07, jim stephens via cctalk wrote:
I hope you get information on Don Tarbell's work
included. He had an
early single density controller. Then later a high (double) density
controller.
I purchased Don's SD controller way back when--and assembled it myself.
I still have it, and his manual.
I got it to replace the 2-board IMSAI controller that used an NEC 8080A.
That board was far from reliable.
Don's controller used the WD1771, so I don't know what that has to do
with Intel and NEC.
--Chuck
11:46 a.m.
WD was first and its line of FDCs with compatible suppliers competed with NEC/INTEL's
line, see https://en.wikipedia.org/wiki/Western_Digital_FD1771
The IBM PC's usage of the uPD765 gave prominence to the NEC/Intel line.
At this point I can't really say which if either came to dominate the market but in
the end the function wound up in the "southbridge" and then pretty much
disappeared.
I suspect NEC/Intel might have won - the Microchip (SMSC) FDC37C78 was one of the last if
not last chip in production - it was a "Licensed CMOS 765B Floppy Disk
Controller" and may have been in production as late as 2013
There are lots of chips for sale on the Internet but they look to me to be salvaged or
surplus chips - does anyone know of chips in current production?
Was Microchip/SMSC the last (Microchip acquired SMSC in 2012)?
Some other late chips with dates from documents:
* Toshiba TC8569AF 1989?
* Hynix GM82C765B
* Intel 82078 1996?
Tom
-----Original Message-----
From: Chuck Guzis [mailto:cclist@sydex.com]
Sent: Saturday, September 03, 2022 8:47 AM
To: jim stephens via cctalk
Subject: [cctalk] Re: Floppy Disk Drive Controller History
On 9/3/22 02:07, jim stephens via cctalk wrote:
I hope you get information on Don Tarbell's work
included. He had an
early single density controller. Then later a high
(double) density
controller.
I purchased Don's SD controller way back when--and assembled it myself.
I still have it, and his manual.
I got it to replace the 2-board IMSAI controller that used an NEC 8080A.
That board was far from reliable.
Don's controller used the WD1771, so I don't know what that has to do with Intel
and NEC.
--Chuck
1338
days inactive
1339
days old
4 comments
3 participants
participants (3)
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Chuck Guzis -
jim stephens -
Tom Gardner