27 Jul
2007
27 Jul
'07
6:51 a.m.
From: "Chuck Guzis" <cclist at
sydex.com>
On 26 Jul 2007 at 21:59, dwight elvey wrote:
Hi
When I worked at Intel, I was responsible for test of the analog board
that went with the 3000 series controller board.
It seemed that even at the time, most of the engineers were
only digital and something like a PLL or balanced mixer were
beyond them.
I did find a bug on the controller cards. It seems that there was
a race. It was on one of the lines from the ROMs that controlled
one of the states. The problem was that the newer ROMs
were getting too fast and the outputs were changing too
quickly. I don't recall what was done to fix that but I thought
it was interesting. I believe they added a little more delay
to one of the clocks.
Dwight
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http://newlivehotmail.com
I'm only familiar with the 2901 and 3000.
I've looked at the
signetics 8X300 but that is more of a halfway between uController
and bit slice.
Dwight
MMI's 6701 was *very* close to the 2901. There was also Moto's 10800
ECL series and some early Fairchild (3800?) parts, as well as Intel's
3000 series (you can find that on the old MDS-800 8" floppy
controllers).
27 Jul
27 Jul
8:32 a.m.
On 27 Jul 2007 at 6:51, dwight elvey wrote:
When I worked at Intel, I was responsible for test of
the analog board
that went with the 3000 series controller board.
It seemed that even at the time, most of the engineers were
only digital and something like a PLL or balanced mixer were
beyond them.
One thing I recall about the MDS floppy controller boards is that
they ran hot as a two-buck pistol. That was probably true of most of
the bit-slice stuff of the time.
Around that time, I'd heard something concerning the Intel 8272 (the
8271 was apparently a horrible botch) FDC that I've long wondered was
true or not.
I'd heard that Intel started development on the 8272, but couldn't
quite pull it off, and traded the basic design to NEC in exchange for
NEC's graphics controller. NEC completed the design as the uPD 765
and licensed it back to Intel. Is there the slightest grain of truth
to this?
The 765/8272 in any case was too late for our own development. Like
a lot of other outfits, we went with the gang on Red Hill Road for
FDCs.
Cheers,
Chuck
10:40 p.m.
From: "Chuck Guzis" <cclist at
sydex.com>
On 27 Jul 2007 at 6:51, dwight elvey wrote:
Hi
This all happened after I left but I find nothing that you've stated as
being too out of line for Intel. The two board sets only did FM or M2FM,
depending on version. I don't recall but I think there early ones only
did FM. It wasn't until the 8272 that they had MFM.
The Series II internal only did FM, I wonder if that used the 8271?
Dwight
_________________________________________________________________
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When I worked at Intel, I was responsible for
test of the analog board
that went with the 3000 series controller board.
It seemed that even at the time, most of the engineers were
only digital and something like a PLL or balanced mixer were
beyond them.
One thing I recall about the MDS floppy controller boards is that
they ran hot as a two-buck pistol. That was probably true of most of
the bit-slice stuff of the time.
Around that time, I'd heard something concerning the Intel 8272 (the
8271 was apparently a horrible botch) FDC that I've long wondered was
true or not.
I'd heard that Intel started development on the 8272, but couldn't
quite pull it off, and traded the basic design to NEC in exchange for
NEC's graphics controller. NEC completed the design as the uPD 765
and licensed it back to Intel. Is there the slightest grain of truth
to this?
The 765/8272 in any case was too late for our own development. Like
a lot of other outfits, we went with the gang on Red Hill Road for
FDCs.
28 Jul
28 Jul
12:04 a.m.
On 27 Jul 2007 at 22:40, dwight elvey wrote:
This all happened after I left but I find nothing that
you've stated as
being too out of line for Intel. The two board sets only did FM or M2FM,
depending on version. I don't recall but I think there early ones only
did FM. It wasn't until the 8272 that they had MFM.
The Series II internal only did FM, I wonder if that used the 8271?
I remember that we had the original MDS-800 and it came with single-
sided FM drives. We then got a series II, but with the 2-board MFM
controller, which also did FM. I may still have some ISIS-II
diskettes from that. IIRC, the first track of both the FM and MFM
floppies was FM.
There were some interesting LSI floppy controllers wandering around
for a time, even though it seems that the WD stuff was the most
common. Moto had a 6843(?) that did FM.
I recall that the 8271 had a mode bit to set if it was being used
with the old double-disk-single-positioner PerSci drives (the only
LSI controller I've ever seen with that feature).
There was a bipolar floppy controller for the Signetics 8x300
microcontroller,the 8x330, that was less of a controller and more of
a floppy interface for the 8x300--the '300 had to scan for address
marks and so forth and twiddle bits in the 330 to change modes.
I've been trying to recall the LSI controller that allowed one to
program (via registers) the clock and data patterns for address
marks. I'm pretty sure it was FM-only, but beyond that, I'm drawing
a blank.
Cheers,
Chuck
8:01 a.m.
From: "Chuck Guzis" <cclist at
sydex.com>
---snip---
I remember that we had the original MDS-800 and it came with single-
sided FM drives. We then got a series II, but with the 2-board MFM
controller, which also did FM. I may still have some ISIS-II
diskettes from that. IIRC, the first track of both the FM and MFM
floppies was FM.
Speaking of ISIS-II, I wonder if anyone has tried to collect the files
that were in the user library that Intel had at the time? There were
a lot of useful programs there for the 8080 and 8085. A while back
I stopped by the Intel Museum. They didn't have much of anything.
They seemed to be just advertising for the latest processor with
little about where Intel had been.
I do think you're right about reading FM on the first track.
That was kind of standard for older 8 inch disk.
My Olivetti M20 does that with 5-1/4 disk. I guess it is a carry over
from the CP/M days.
It made copying my M20 disk
hard until I found a controller that
ran single density. For the M20, the first track was just disk setup
information and the same for most all. I had to first format a disk
on the M20 and then overwrite the rest of the tracks with the
new data.
Dwight
_________________________________________________________________
Local listings, incredible imagery, and driving directions - all in one
place! http://maps.live.com/?wip=69&FORM=MGAC01
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