If you used discrete components how big would it be?

Quite voluminous, with lots of cables and metal cabinets
and a heck of a power-bill and airconditioning system.

An example would be an IBM 360

http://www.columbia.edu/acis/history/36091.html
http://www.thegalleryofoldiron.com /
http://homepage.virgin.net/roy.longbottom/cpumix.htm

What the ?? they dont use fully discrete  circuits. They use chip ram at
least.

Plenty of the 360s didnt.

And plenty of the older stuff like the 7090 did anyway.

Ferrite toroid core memory was possibly used in that era.  These could
be made into quite small sizes (though massive compared to silicon
RAM).   These arrays would be driven by power transistors - though
being arranged in a matrix grid, this would drastically cut the number
or driver transistors that would have been needed.

Still have a board of it here somewhere that I never bothered to chuck
out.

Is that like a board of tiny donut rings?

I've seen one very briefly at a TAFE way
back in the 80s when I did a computing course.

They were teaching courses in BASIC because
at the time it seemed popular. Around  1982 /83

They werent normally done on a board.

On Sun, 27 Mar 2005 14:23:30 +0930, Chasing Kate


I can post a pic of it for you, it came from a junked STC mainframe
that I bought cheap 20 years ago for all the parts/hardware and such,
and I kept this board for some reason

has GA 1972 on it - it appears to be a CAD designed multi layer board
that contains many heatsinked transistors and power resistors and
other ic;s, and then there is a smaller plug in PCB in the middle with
the core array on it.  the cores are really too small to see with the
naked eye clearly - its just a very neat (and arty) arrangement of
very fine tinned copper wire.

I would hate to think how much this system would have sold for new in
the early 70's. specially since it all would likely have been hand
made.
--------------------------------------

The other time I have come across toroid memory (called TORMAT in this
case) is in SEEBURG brand Juke boxes.  they had 200 positions (one for
each side of 100 records) and in the 50's when first used for this
purpose - were driven by vacuum tubes.

they were used well into the 1970's in these machines, but by then
were controlled by solid state circuitry.  I believe in this (very
very basic) application that they were extremely reliable (and
probably light years ahead of the motorised pin-bank memory used in
the other brands).

There are still web pages around with lots of detail on how to service
and repair these tormat units - a quick google will surely reveal
detail on how these systems work and can be fixed (as the machines are
very collectable and many out there still want to keep them working)
if you have an interest in their operation.

-------------------------------------

Fascinating sites thank you

The Pentium 4 alone has 50+ Million transistors, not to mention support
chips. Would you like some memory with that?
You do the math...
Of course the size would depend on what package your discretes are in
and what kind of board and loading you used.
Performance could be a bit sluggish too... :->

Dave :)

OK for example transistors in the tiny black
plastic they usually come in.....  I can well
imagine how big it would be LOL.....

I was asking out of curiosity

Actually I thought about my original reply to you
and what if we included small ICS such as gates
and counters and similar logic devices into the
mixture?  Would that make the computer any smaller
then if you used transistors on their own?

It didnt with the PDP15 which was a PDP9 done like that.

Or the 360/191 either.

It did however see the PDP11s quite a bit smaller than say the PDP15.

The PDP11 and PDP8 eventually ended up very similar
in size to a modern PC, tho with rather less memory.

Depends. Faced with the necessity to provide a special room solely for
the home computer, most people were sit down and do some serious
thinking about what facilities they really needed and could afford.

My 2c is that 90% of modern computer capacity is wasted and never used.

Shit, where I work probly only about a quarter of what we have flies
along, the rest labours intensely under the kind of loads we put on it,
and my home PC is just the same, doesn't matter how many times I
upgrade, the resources run dry within 6 months and things start to
slowww down. The problem is it's much easier to write software that
utilises additional processing power/memory/storage space/graphics
capability/etc.etc. than it is to design hardware to cater for it.

Don't confuse grunt (speed, ram, etc) with facilities (SIO, PIP, USB,
Fire, Midi, etc)

Besides, you might work in Game development or GIS or Video editing,
which I agree are very demanding.

yes but its the unused features of the software that cause bloat.

and these computers may be stalled by the lack of ram, or by slow hard
drives


I dont know how to derive the 90%. That may well be wildly inaccruate. maybe
its 60% or 99%.
 

I have 1/2 gigabyte of ram.


thats 4 gigabit. 4000 million bits.

Each bit requires one transistor  and one capacitor, and then theres
overhead.

The rest of the system hardly adds many transistors to that.

but  4 billion transistors is going to take a lot of discrete components !

But just think of how many jobs board level repairs would create!

David

Fred Ferd wrote:

   You would never get that many boards working at one time, and the
buss speed would be in the KHz range due tho the size of the system.