>From: "Richard Erlacher" <edick(a)idcomm.com>
>
>Now I'm really confused, Joe. Thanks for stirring the coals, though.
>
>I can't find any Intel memory data before '82, and by that time they were on
>5-volt-only EPROMs all the way. The brocheure I'm thinking of, with respect
>to that 8748 evaluation board, has the "it's a 5-volt world" slogan that Intel
>liked to use in promoting the 2716 back then, but I'll find the '78 8748 book
>eventually, since I just looked at it yesterday.
>
>'t seems like I'll never learn to keep house ...
>
>Dick
>
Hi
I believe the half bad 2716 of Intel's were call either
2758 or 2508, not 8708. I'm almost sure that the 8708
was the one that could handle the negative bus levels on
the input, as I said earlier. You are correct that they
sold the H and the L version for the level to put on
the A10.
Dwight
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>Date: Mon, 06 May 2002 15:29:52
>To: classiccmp(a)classiccmp.org
>From: Joe <rigdonj(a)cfl.rr.com>
>Subject: Re: 2708 Programming Algorithm?
>MIME-Version: 1.0
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>Content-Transfer-Encoding: 7bit
>
>Steve,
>
> I don't have the programming instructions for the 2708 but I do have them
for the intel 8708 and intels later manuals state that they're the same. Here's
what I have in the sept 1975 8080 Microcomputer Systems User's manual.
>
Hi
I believe the main difference between the 2708 and 8708 is that
the 8708 could handle negative levels on the data bus so it
could be connected directly to the 8080's data bus.
Dwight
>>> I just remember that all the 87xx parts, 8741, 8755, 8748/49, etc,
were all
>>> 5-volt parts. further, I'm not at all sure that the 8080 had
below-ground
>>> signal levels, since they were intended to be attached to bipolar
parts, e.g.
>>> 8212, etc, which would have been intolerant of that. What I've got
in my lap
>>> is the 8080A data, which may, actually be different, but IIRC, the
8080 needed
>>> the negative bias supply so it could swing to ground and the +12 so
it could
>>> swing to a reasonable high level. My only contact with the 8080 was
on boards
>>> made by Intel, and, while I poked around with a 'scope and other gear
from
>>> time to time, I don't recall ever finding an address, data, or
control signal
>>> that wasn't TTL compatible.
Wrong! the 8080 and 8080A had basically the same levels and drive. the
issue
of negitive voltages on the output is a red herring.
The 8708 accoring to the 1978 8048 manual is a THREE voltage part with
the exact pinout as 2708. It's of course an intel number to allow the
"kitting:
practice that intel did do back then... "FAE>>> ya gotta use 8xxx parts".
Now for a note, looking at the 1979 Intel component data book the 2708
is
listed and save for a faster programming method the 8708 is identical per
notation in the data book!
Recommended programming pusle width is .1 to 1 millisecond and the
programming loop should not program any location for more than a total
of 100mS. Though I remember programmin them using a 1ms pulse and
doing a read to see if it took, programming it 5 times more for over
program and looping till it took and moving on to next location. If a
location
took more than 90 hits is was flagged as bad. That seemed to get the
best life out of the parts according to my notes. FYI: over eraseing
them seemed to kill them too.
Programming voltage is nominal 26V pulsed! All other votages are static
(Vcc, Vdd and Vss) with *ce/we being driven as needed for read or write.
> That's not the point. The point is that the inputs and outputs are
TTL (0V/5V) level and not a negative voltage. FWIW IIRC even the 8008
had a fan out of more than one. I have the manual and can look if it
matters.
Correct it was 2 LS loads. And the old 4004 was ttl if used with the
correct supply
voltages -10 and +5 wich was typical of the PMOS logic.
Allison
The Rhode Island Computer Museum ( see www.osfn.org/ricm ) would be very
interested in your NorthStar Horizon parts. We have an Horizon chassis,
backplane/motherboard and wooden cover (in "repairable" shape), but
precious little else, and I am looking to fix that omission. Please
note that the Rhode Island Computer Museum is an IRS-recognized 501(c)
charitable organization, so any donations made are tax deductible.
Please contact me at your earliest convenience:
Mr. Geoffrey G. Rochat
Vice President, Rhode Island Computer Museum
1 Barrows Rd.
Mendon, MA 01756
geoff(a)pkworks.com
508-478-1748
-----Original Message-----
From: Brain, Jim <JBrain(a)aegonusa.com>
To: 'classiccmp(a)classiccmp.org' <classiccmp(a)classiccmp.org>
Date: Monday, May 06, 2002 6:04 PM
Subject: Northstar Horizon Stuff
>I just found some old N* Horizon parts during a cleaning fit. I have
the
>following:
>
>Lots of hard sector disks
>2 64 RAM board.
>2 FD controllers
>2 Z80B boards
>2 FD drives
>1 motherboard
>
>I do have the cases (with the PS and such, but only until Thursday,
since
>they are scheduled to be pitched this week. They aren't in the best of
>shape, and they are SO heavy, so I pulled what I thought was worth the
>shipping weight cost out of the 2 units. If you do want a case part or
a
>capacitor, let me know before Thursday so I can have my wife pull the
part
>off the chopping block.
>
>Anyone interested in S100 parts and hard sector disks? The units were
>working last time I used them, but that was 5 years ago. I make no
>promises. If there are a few folks, I want to spread the wealth.
>
>Basically, I just don't want the parts to sit in the landfill.
>
>You might want to email me directly, to not clog up the list, and
because I
>have limited access to email this week while out of the office and
lists
>will probably get queued until next week.
>
>Jim
>
>
>Jim Brain, jbrain(a)aegonusa.com
>"Researching tomorrow's decisions today."
>(319) 369-2070 (work)
>SYSTEMS ARCHITECT, ITS, AEGON FINANCIAL PARTNERS
>
>
>
>
>From: ajp166 <ajp166(a)bellatlantic.net>
>
>>>> I just remember that all the 87xx parts, 8741, 8755, 8748/49, etc,
>were all
>>>> 5-volt parts. further, I'm not at all sure that the 8080 had
>below-ground
>>>> signal levels, since they were intended to be attached to bipolar
>parts, e.g.
>>>> 8212, etc, which would have been intolerant of that. What I've got
>in my lap
>>>> is the 8080A data, which may, actually be different, but IIRC, the
>8080 needed
>>>> the negative bias supply so it could swing to ground and the +12 so
>it could
>>>> swing to a reasonable high level. My only contact with the 8080 was
>on boards
>>>> made by Intel, and, while I poked around with a 'scope and other gear
>from
>>>> time to time, I don't recall ever finding an address, data, or
>control signal
>>>> that wasn't TTL compatible.
>
>
>Wrong! the 8080 and 8080A had basically the same levels and drive. the
>issue
>of negitive voltages on the output is a red herring.
I guess I'm wrong here. I just remember something about negative swings
but it was a long time ago.
>
>The 8708 accoring to the 1978 8048 manual is a THREE voltage part with
>the exact pinout as 2708. It's of course an intel number to allow the
>"kitting:
>practice that intel did do back then... "FAE>>> ya gotta use 8xxx parts".
They did make changes in some cases with the leading number.
The 4702A was different than the 1702A in that the negative
rail could be -10V instead of -9V, although, the 4702A would
program and function at -9V. Maybe this is what was confusing
me.
>
>Now for a note, looking at the 1979 Intel component data book the 2708
>is
>listed and save for a faster programming method the 8708 is identical per
>notation in the data book!
>
>Recommended programming pusle width is .1 to 1 millisecond and the
>programming loop should not program any location for more than a total
>of 100mS. Though I remember programmin them using a 1ms pulse and
>doing a read to see if it took, programming it 5 times more for over
>program and looping till it took and moving on to next location. If a
>location
>took more than 90 hits is was flagged as bad. That seemed to get the
>best life out of the parts according to my notes. FYI: over eraseing
>them seemed to kill them too.
These can be baked if they are in the ceramic package. This
brings them back to life. When I was in the lab, we did this
often. I don't recall the temeperature we used.
The 2716's were more robust. We left some under the UV light
for weeks and had no data retention problems ( although, we
only required them to hold for about 6 months instead of 10 years ).
Dwight
>
>Programming voltage is nominal 26V pulsed! All other votages are static
>(Vcc, Vdd and Vss) with *ce/we being driven as needed for read or write.
>
>
>> That's not the point. The point is that the inputs and outputs are
>TTL (0V/5V) level and not a negative voltage. FWIW IIRC even the 8008
>had a fan out of more than one. I have the manual and can look if it
>matters.
>
>
>Correct it was 2 LS loads. And the old 4004 was ttl if used with the
>correct supply
>voltages -10 and +5 wich was typical of the PMOS logic.
>
>Allison
>
>
> FYI: over eraseing them seemed to kill them too.
Intel ROMs also had another strange behavior when
exposed to too much UV... they'd only work with a
little light (possibly needing some UV). I may have
told this one before, but one embedded system I
did suddenly stopped working when we close it up
in a box. Open it up, it would work.
On my suspicion that light was involved, we ran
it in a dark room; no run. Shined a flashlight on
it, ran fine!
A conversation with an Intel tech verified this
was possible. Too strange, tho...
-dq
>Names like "chooser"
>for something that doesn't choose, and "finder" for something that doesn't
>find, is pretty confusing.
Well... the Chooser is used to "choose" your printer (and network server,
and sometimes fax modem, or PDF converter, and occasionaly a scanner, and
once in a while some other stuff)
And the Finder is used to find and locate your files on the hard drive,
floppy drive, or other storage device... as well as to launch them,
modify them, copy them, delete them, and do pretty much anything else
that interacts with them, or applications, or many other parts of the Mac.
What's so confusing about that? :-)
(yes, that is a joke... Finder and Chooser are some fairly odd names for
what they do)
-chris
<http://www.mythtech.net>
From: Doc <doc(a)mdrconsult.com>
> I've been wondering, based on some old posts to the CP/M groups. Will
>the same disk, for example an ST251, format and work off either an MFM
>or an ESDI controller? Totally true, totally false, depends on drive?
> For that mmatter, is there a good newbie-level reference for the 2
>interfaces? They were history when I started playing with keyboards,
>and I never dreamed I'd need to know.
The problem with EDSI was it sued the same cables as MFM IE: the pair
of 26 pin and 34pin. The interfaces however were toally incompatable.
No, a St251 would not interface to EDSI. It will interface to both MFM and
RLL though RLL may/may_not be reliable with that drive. I have used ST225s
with RLL controllers to get ~30mb from them (st225 is 20mb MFM).
Allison
> -----Original Message-----
> From: Richard Erlacher [mailto:edick@idcomm.com]
> Maybe someday someone will write a DOSEMU that works like
> DOS, and a WINE that
> actually executes Windows App's. That would go a long way to
> ending the MS
> monopoly on user-friendly, and make it possible for 3rd-party
> application
> developers to get up some applicatons that really work.
Heh -- I'm sure M$ has a monopoly on something, but it certainly
isn't "user-friendly..." Even if you define user-friendly as
"acting just like windows," there are a few other things around,
regrettably, that do that these days.
That aside, though, have you tried Wine recently? It's coming
along nicely, and DOSEMU looks a lot like DOS to me.
Did you mean to single DOS out as being "user-friendly?" I ask
because it doesn't strike me as exceptionally so...
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
'
Peter,
I have a lot of old Interak stuff, including literature. It is in my loft and will be thrown away (I keep saying). Is it of interest to anyone.
Cheers
Errol
