At 12:10 AM 06-10-98 -0400, William Donzelli wrote:
>> Well I'd add a Ferranti Atlas for all the obvious reasons.
>
>I probably should have added some foriegn iron, but I must admit, I am
>unfamiliar with it. Certainly some of the big Japanese and British stuff
>would count.
The Atlas is famous for two important things - virtual memory and
timesharing. The Atlas was the first commercial machine to have hardware
support for paging and hence virtual memory. A neat timesharing system
resulted. I also seem to recall a nice Algol compiler for it too. I'll see
if I can remember to check my copy of "Algol-60 Compilation and Assessment"
which will have the gory details :-)
Huw Davies | e-mail: Huw.Davies(a)latrobe.edu.au
Information Technology Services | Phone: +61 3 9479 1550 Fax: +61 3 9479 1999
La Trobe University | "If God had wanted soccer played in the
Melbourne Australia 3083 | air, the sky would be painted green"
>> I've always wanted to know which machines have only a single instance
>> represented on this list.
How about an ExelVision EXL100 I don't think they ever made it to this side
of the atlantic. Of course you UK people have a chance to have one but I
believe it never made it out of France (except for mine:)
As far as the holly grail list: yep one of each would be great.
Francois
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Visit the desperately in need of update
Sanctuary at: http://www.pclink.com/fauradon
< I've been sketching ideas based on a rocker that is threaded on a rod. T
Smooth rod with a return spring and seperators between teh switches.
< back of the rocker contains a 'paddle' which when the rocker is down,
< breaks an IR/detector gap. This has a couple of benefits. One the rocker
No question it's more reliable... what about dust. How about hall effect
switches?
< switch register - what size? Could have 8 to 32 bits if we wanted
Number of bits is based on CPU native word size.
< I've about half decided to build something PDP-8 like out of PIC chips.
< They are relatively cheap, easy to program, and quite fast. I hadn't
< thought about using them as base units (microcode sequencer, ALU control
< etc) until this discussion began, but it also raised the point of
Doable but not many are needed as the 8 series had a single accumularot
and the amount of random logic that is not control related is small.
< 'emulators' and I began to wonder what if you build a Z80 system that
< emulated a PDP-8 with one of these custom front panels. That turns out t
< be more of a software effort than a hardware effort.
It was done on an 8080 in the mid 70s using a terminal as a text graphics
display.
< You can get PC boards made fairly cheaply, if you wanted to do a transis
< based CPU I would definitely consider having a few hundred 'flip chip'
< equivalents made. It wouldn't have to be 1:1 DEC replacements but they
< showed it could be done. Wiring up 12 flip flops by hand on a piece of p
< board (4 transistors each!) would be extremely painful.
Yes it would also the shear number even at a penny(US) each would scare
most people as something like an straight-8 used a few thousand.
Resistors aren't cheap nor caps so that scales up real fast. Transistors
if used would be a good thing for doing a serial machine as they have
lower parts counts and few hardware "registers". Not modern silicone
transistors do not have close to similar characteristics to the old
grown junction or MADT germainium devices so circuit chages would be
required.
< First, find a 50Amp 5 volt supply. :-) The thing about TTL logic that
< always amazes me is how much power it draws. I built a digital PLL out o
< TTL chips once (about 40 chips) it was easily drawing 3-4 amps at speed
< 74HC logic might be a good compromise here.
I've done some heafty TTL designs (one was 200 chips SSI and some MSI)
and it didn't need near 20 amps never mind 50. I don't thing the 8E PS
can do more than 35A.
Besides a simple design is possible without meltdown for heat.
< computers called the 'beer budget graphics display' and was featured in
< BYTE magazine in the late 70's. Basically this was two R2R D/A ladders
< driving the X/Y inputs to an oscilloscope. If you make a 12 bit machine
< could build a 4K x 4K resolution display fairly easily. (You will be cor
I built it using a 8bit R2R ladder and that is the limit of that design
for a lot of reasons. It settles slow (more than 10uS settling time)
and the high order drivers to the R2R ladder have to supply some power.
A later published design used 8bit moto1408, also slow.
Or scale back to 1024x1024. This is known as vector graphics and the
real limitation is how many vectors can you draw before you have to go
back and redraw (flicker/refresh) which is a fuction of DAC speed, CPU
speed and crt driver speed.
It was the display common to the PDP-1, and seen on 8s and even some 11s
for early graphics.
Allison
< I'm not sure how useful a definition it is. Why, for instance, isn't m
< PDP-8/I considered to be microprocessor-based? It has a multi-chip
< processor. So did the IBM 360/30, for that matter.
The 8I was a TTL cpu and was a lot of DEC cards interconnected to make
a minicomputer. There is no one board, or 15, in an 8I that could be
called the CPU or even the core processor. The 8E did reduce that to
three cards timing, major registers, major registers control.
The dividing line is level of integration. The F14 CADC basically put
those three 8E card into one ot two chips.
< While I would be the last person to want to downplay the significance o
< the F-14 computer, I personally think that the word 'microprocessor' is
< only useful if it refers to a single monolithic IC, in which case Ted Ho
< and Intel get credit for the first one.
Microprocessor is a functional name ie: what it do, not what it are.
So in most senses microcomputer and microprocessor are one and the same
but not always interchangeable.
Allison
< Yes, but DEC had a strange definition of 'microprocessor'. They sometime
< used the term to mean 'microcoded processor' - as in the microprocessor
< board for the DMC11, etc which certainly wasn't a single-chip processor
< (it was a hex-height card of TTL).
Microprocessor... the RX01 disk controller (drive end) is a board of ttl
and proms. It is a micro, meaning small, processor, it performs a set
procedure of actions "process" upon data or system (disks and the data for
them).
The RX01 contains a microprogrammed microcontroller as its microprocessor.
I'd think that was clear enough. ;)
Allison
Help! This is a weird one.
I have a Sun Remarketing Macintosh XL (a.k.a. Lisa 2 modified). It has
Sun's Parallel-to-SCSI card which runs a ribbon cable out the back of the
machine and plugs into the external parallel port. OK, I've heard of such
configurations, so far, so good.
Problem is, neither the Kalok SCSI hard drive nor the 800K floppy drive spin
up when I power on the machine. I pulled out the drive enclosure, and there
is no power connected. The Sun Parallel-to-SCSI has a 6-pin right-angle
power connector on it. There is a loose power connector in the drive area,
but it has only 3 pins on a totally different spacing. What is going on
here?
thanks!!
Kai
< Sam wrote:
< > Anyway, the F14 CADC SLF chip can be classified as a single-chip
< > microprocessor. I say "can" because you've get a different definition
< > microprocessor depending on whom you ask.
<
< OK, let us know the definition, so that we can decide whether the LSI-1
< chip set also qualifies as a microprocessor. Then we can settle the tri
< question regarding which microprocessor-based Unix system came first.
Dec sold the LSI-11 and later chip based systems as microcomputers.
Source for this is the bindings of not less than 7 databooks and
technical descriptions. Also the T-11 member of the family is a single
40pin dip with one die inside.
If that werent' the case the fairchild F8 would not qualify as a single
chip CPU due to the need for multiple chips and the same would apply to
the predecessor to the RCA CDP1802.
allison
Sam, if you need an example you can go to Halted in Sunnyvale and look on
their row next to the test bench. They have a 20Amp 120v Variac on the
shelf. It's about 8" around with a funky steering wheel like knob on the
end. (they want $350 for it so its probably still there ;-)
--Chuck
Already looking for next years VCF door prize?
-----Original Message-----
From: Sam Ismail [SMTP:dastar@ncal.verio.com]
Sent: Monday, October 05, 1998 3:33 AM
To: Discussion re-collecting of classic computers
Subject: Working PDP-10 anyone?
Does anyone know off-hand where there might be a complete, working PDP-10
system?
Sam Alternate e-mail: dastar(a)siconic.com
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