>The other thing is that the 9100 is incredibly simple. Seriously. HP
>pulled all sorts of tricks to reduce the component count, not all of
>which would be applicable to other designs.
Not only did they pull all the tricks, but they made a very nice product
in the end, too.
Gees, there was this other HP engineer famous for low component counts,
started this computer company in the 70's when HP decided they weren't
interested in his ideas. I think the guy goes by the name Wozniak and
for some reason I believe Apple is still around :-).
Tim.
--- Doug Coward <mranalog(a)home.com> wrote:
> Dave Dameron wrote:
> > The bad chips were all made by TI.
I, too, have had bad experiences with 1970s TI chips and pin corrosion. I'm
wondering if that's the problem with my Heathkit H-27 controller. No broken
pins but lots of blackened ones (silver oxides).
> Four of the 5 broken chips are TI 8T26s and the fifth is a TI 74123.
> --Doug
Not that I normally advocate this sort of cannibalism, but does not the Apple
][
use 8T26 bus buffers? They certainly are more common than OSI gear.
-ethan
=====
Infinet has been sold. The domain is going away in February.
Please send all replies to
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__________________________________________________
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Bid and sell for free at http://auctions.yahoo.com
You are quite right Mike.
I personally know some of the owners/controllers of some of the largest
scrap companies (thats how I get all my minis) and the guys I deal with get
contracts to level factories and mills. They don't know what a PDP 8 is and
don't care. They want to either relocate some of the major machinery or
melt it before setting the explosives in the building. Most of these
companies don't care if you'd be willing to pay $1000 or even $2000 for a
PDP as most of the contracts they get are worth millions.
Best approach I have found is accept ANY and ALL minis/mainframes that come
their way. I don't dicker with them and don't him and ha... If they have an
old Wang or some old IBM then I take it anyway and scrap it for parts...
A company I am going into at the end of this month has minis that were
installed before 1968. No one has any idea what they are and no one cares.
The factory is being levelled in middle November and anything that is left
will have the building dropped on it. (I did however find out from a prior
purchasing officer that the systems I am pulling out are:
Vax 11/780 - yuck, I'll trash that.
IBM 360 and/or Classic PDP 8 (seems they possibly had both)
and other minis that controlled various processes
The controller refered to old system as a "huge computer that filled up a
room , we didn't get rid of it because it wasn't worth moving".
If you have deep pockets to buy every computer mini they find in an old
factory then you can score quite often.
john
-----Original Message-----
From: Mike Ford <mikeford(a)socal.rr.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Tuesday, October 19, 1999 3:36 PM
Subject: Re: Approaching Scrappers
>>on them, but to no avail. They have bigger fish to fry
>>(like aircraft fuselage assembly jigs, for example).
>
>Man I am really suffering from rejection. One of the salvage joints I like
>just made the back room closed to everybody including me. Bigger fish to
>fry, insurance, theft, etc. and now nobody can look in the boxes. I'm
>getting a bit shaky already, and the withdrawal hasn't even hit strong yet.
>I gotta find a new yard to poke in soon, or who knows what could happen (I
>might fix the upstairs toilet or something crazy).
>
>Maybe my point is approach with caution. Like it or not, you aren't the
>thing that pays the bills at the end of the month. They may like that cash
>once in awhile, but don't do ANYTHING to disturb the main money flow. Help
>out if you can and the person wants it, ie sort out a box of cables etc.
>
>Nothing gets you in tighter with a scrapper than giving them leads. Give
>them a contact that pans out with a contract, or even a one time deal, and
>they may even answer your phone calls.
>
>
-----Original Message-----
From: Chuck McManis <cmcmanis(a)mcmanis.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Wednesday, October 20, 1999 3:13 PM
Subject: Re: Designs (was Re: OT: how big would it be?)
>At 02:28 PM 10/20/99 -0400, Allison wrote:
>>Flip chips, M series and all were really dictated not by what could be put
>>on a board but how many connections the bord could make. For a flip chip
>>it was 18 or 36 (someone?). A 16 bit parallel load register like say a
>>pair of LS573s would need 32 IO, plus power and controls. See the
>>problem?
>
>Ok, so this suggests a possible solution/idea. We use simm sockets. You can
>get them fairly cheaply, there is a wirewrap version, and the PC houses all
>have a standard template for the bottom of the board. I suppose one could
>even make a Q-bus that small (its 72 pins as well IIRC).
You bring up a good point. If a board can be designed with TWO connections
to the simm socket (one on top, and one on the bottom) so that you would
flip the board for one operation and flip it the other way for another
operation then prob. two different types of boards could be used for the
whole CPU:
ie:
BOARD 1
side 1: 4 FF, 2 Inverters, 2 nand/nor
side 2: 2 xor, 2 and/nor, ???
BOARD 2
side 1: one shot, pulse amp, etc..
side 2: more gates and inverters.
limiting the CPU to two boards means I can ship it over to a manufacturer in
Taiwan I have used before. 2 boards in 500 quantities/ea with just
transistors and diodes(+ res + cap) is quite cheap. Maybe they would charge
$2/ea. I designed a Frequency synthesized data transmitter (FM) with synth,
risc chip, and many support transistors for a product. I could not keep up
the production with my guys at the time so we shipped it off to Tiawan and
they knocked them out in Qtys of 500 for $8 ea (PCB, parts, built and
tested). I could not even buy the parts in qtys of 5000 for $8 here.
Anyway, it seems this CAN be done quickly and cheaply if two boards can be
standardized with a series of gates and flip flops.
Should be serial, smaller and more fun!
john
>
>Unlike Tim I think TO-3's would be way to much of a pain, but TO-92s are
fine.
>
>--Chuck
>
>> Are they the correct technology? I like 'em because you can get to parts of
>> the circuit easily, but it is more compact to put everything on just a few
>> boards.
>Flip chips, M series and all were really dictated not by what could be put
>on a board but how many connections the bord could make. For a flip chip
>it was 18 or 36 (someone?). A 16 bit parallel load register like say a
>pair of LS573s would need 32 IO, plus power and controls. See the
>problem?
>
>Even TTL chips hit the wall in pins/functions per package.
Exactly - it's not a question of "do we have the parts?" but "Can
we connect all the parts together usefully?".
Is it true that the first CPU-on-a-single-board was the DG Nova?
(And it's a rather largish board, at that! Almost equivalent in
area to all the boards in the PDP-8/E CPU put together...)
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
>I have trouble with the notion of the uart filling a 9 x 11 board given
>that I'm holding one that's occupying 4 x 5 inches in SSI. Yeah, the shift
>registers would take a bunch of space but I don't see it using anywhere
>near the amount of real estate suggested.
I'd suggest a electromechanical (or optomechanical) UART instead. You
know, like in a Teletype :-).
>> A pdp-8 (early) had a pannel roughly 24"x50" with flip chip modules mostly
>> transistors and the 4k core was a 10" tall rack section. for rough
>> comparison. In many respects the 8080 is a far more complex CPU and would
>> be significantly bigger. It would also be slow compared to the NMOS part.
>I suspect you could build a pdp-8 using contemporary layout tools and discrete
>technology that, excluding the core stack, was an order of magnitude smaller.
And repackaging would also save a lot of money: a large part of the cost
of a Straight-8 is all those gold plated fingers and edge connectors, and
the backplane wiring. Get rid of that - so that your CPU resides on
a single (even if large) PC board - and you're way ahead. (Well, way
ahead if everyone else is still in 1965...)
>> Doing it in ttl or bit slices would still be big, I've done that. using
>> 2900 parts(ca mid to late '70s) the CPU equivelent was over 100 chips and
>> filled 4 10x8" cards.
>That sounds about right; I recall building a PDP-11 clone using 2901/2910 parts
>as part of an undergraduate CPU architecture course in the same era and using
>about the same number of parts.
Of course it's also possible to do it on a single card using SSI and
MSI TTL, maybe with a few bipolar PROM's. Take a look at the 11/04 CPU or
the original Nova, for example.
I recall - back in the mid-70's - that Radio Shack sold transistor-based
logic module kits (PC boards) that could be strung together to make
things like binary counters, etc. Does anyone else here remember these?
Or, even better, still have the modules around?
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
>Well . . . if you mean really discrete, i.e. no TTL SSI/MSI stuff, you need
>to recall that a single flip-flop was resistors, capacitors and a handful of
>transistors.
>...
>There, methinks you'd be talking about a board as big as your dining room
>table, with miles of wire, and potentially millions of errors to correct.
No, it doesn't have to be as big as a dining room table. Like I said,
I own several examples of bit-serial processors implemented using
discrete components - for example, my Monroe programmable calculator -
which pack everything onto a few square feet of printed circuit board,
and not incredibly dense PCB's at that.
There are other examples of bit-serial processors in my collection -
for instance, the HP 9100A - where there is some, but not much, integration
used. The big PCB in the 9100A is the ROM, while the processor itself
resides on a daughtercard!
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
Well . . . if you mean really discrete, i.e. no TTL SSI/MSI stuff, you need
to recall that a single flip-flop was resistors, capacitors and a handful of
transistors. Really cramming the parts together still meant a flipflop took
up space equivalent to, say, a postage stamp. I've seen claims that some
old-style CPU's (e.g. 8080) could be built in programmable logic using fewer
than 500 macrocells in a large CPLD. Now, that's a BUNCH of logic gates,
maybe four transistors and some resistors, and 500 of these postage-stamp
sized flipflops.
There, methinks you'd be talking about a board as big as your dining room
table, with miles of wire, and potentially millions of errors to correct.
Dick
-----Original Message-----
From: CLASSICCMP(a)trailing-edge.com <CLASSICCMP(a)trailing-edge.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Wednesday, October 20, 1999 8:24 AM
Subject: RE: OT: how big would it be?
>>I know its off-topic but i figured that since most of the poeple on this
>>list work or have worked on the really big stuff you'd know better than
>>most others.
>>
>>Say someone were to home-build a CPU from scratch using only individual
>>components, no ICs only modern descrete(?) components. How big would the
>>CPU be? For comparison lets say it would be an 8080 clone. Any guesses?
>
>Well, others have guessed at the 8080 Clone, but I'll step in and point
>out that if minimal part count is an important feature, then you can
>get by with a *lot* less. Especially if you go to a bit-serial
>architecture. (Something that's still mentioned in many computer
>architecture textbooks, even if it isn't used much anymore!)
>
>How big? I'll venture a guess that a 12-bit serial CPU
>could be done on one largish (i.e. a square foot) PC board, using
>TO-92's, resistors, capacitors, and diodes. This isn't too far
>out of line with many bit-serial designs from the late 1960's
>(for example, many bit-serial desktop calculators used a PC board
>- or two or three - about this size.)
>
>Total cost? Maybe $1500 in large scale production, including testing
>costs.
>
>Of course, you now hook up memory to this CPU. Doing that with
>discretes would be a chore!
>
>--
> Tim Shoppa Email: shoppa(a)trailing-edge.com
> Trailing Edge Technology WWW: http://www.trailing-edge.com/
> 7328 Bradley Blvd Voice: 301-767-5917
> Bethesda, MD, USA 20817 Fax: 301-767-5927
> Calling a DS 40 cylinder drive (like the ones in the original PC) an '80
> track drive' _is_ actually correct.
>
> > surely would not disagree that some people [incorrectly] refer to the
> > 100-4 and 1.2M drives as an "80 track" drive. And you certainly won't
>
> However, I also agree with this. Common usage would call the PC 360K
> drive a '40 track drive'. And I will also admit that I tend to make this
> error myself :-(
>
> I will agree that the original statement is confusing, sure. And it's not
> common usage. But it is still correct.
Reminiscent of motoring in Germany. There the signs - and even the inhabitants
- talk about speeds in km. NOT km/h, which is what they mean. Very
confusing...
Philip.
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I'm looking for a diablo 31 or 33 drive (the 31 was the one with
the door, the 33 is the one that you have to rip apart to get
your pack out). I'm also looking for a Decision 3150 controller
for same.
While I'm wishing for the impossible, I might as well add the
other (current) items on my wish-list:
EDS mux boards for the Nova bus
An Eclipse S/200
An Eclipse S/130
A paper tape reader. Hell, I'd be happy with an ASR 33 at this point.
And in the only-in-my-dreams category:
An original ("baby") nova or supernova
An Eclipse S/230
Of course, if it's a 16 bit DG machine, something that plugs into
same or something that just looks good sitting next to it I'm
interested. Cash, trades or body parts.
Thanks,
Chris
--
Chris Kennedy
chris(a)mainecoon.com chris(a)dtiinc.com
http://www.mainecoon.comhttp://www.dtiinc.com
