If you used discrete components how big would it be?

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?

data

You've never seen an early mainframe with 20 foot deep pull out frames that were hinged at the back so you could get two rows of boards in a 24 inch wide space or the poor uptime of those slow, slow slow systems. The system clock was in the low KHz range and those 800 BPI 9 track tape drives were flaky as hell. Early mainframe computers were used more for file sorting than anything else. One reel of tape had customer records. A second drive had the day's accounts and a third drive was the updated files.

As far as union workers, you can have all of them you can stomach. I'll take people who are hired for their skills and work ethics any day.

I've seen one of those(core memory modules) sitting in display cabinets in the electrical department at our Uni(UWA). It is impressive to see thousands of the little toroids threaded on equally thin wire.

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.

Yeah, quite interesting technology.

Needed quite a bit of support transistors to drive it tho and they were a real cow to maintain, setting the slice levels etc.

That was by far the most flakey part of the computer proper, as opposed to the IO devices.

Real ram left it for dead maintenance wise.

The initial roms were basically big boards of discrete diodes which you 'programmed' by cutting out the diodes you didnt need with a pair of sidecutters.

Distinct improvement on toggling the boot loader in thru the front panel switches tho. I used to have the PDP8 boot loader permanently engraved in my brain.

Some have been unkind enough to make snide remarks about that.

And whatever became of Bubble memory?

Does anyone still use it? It had great promise then seemed to die off

What about the stuff on here

They had one item which was the CPU. Basically aa layer of ICs put onto a multi layer cake of ceramic with connections through all of the layers which also contained circuitry.

The whole thing would sit inside a metal case and either be water or air cooled.

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.

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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.

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Those were quite a bit later.

Yeah, similar in concept to a modern PC cpu but rather bigger.

Yeah, and some stuff like the 7600 were essentially refrigerated to cool them with a similar approach.

Rather more plumbing than soldering or wire wrapping.

Never really did fly, like quite a bit of technology.

Nope.

Yeah, too slow basically.

Hey Michael - didn't you see that I was just having a joke? Though of course I was having a shot at union scumbags who would be happy to sit on their bums and wait

David

"Michael A. Terrell" wrote:

data

I guess it just burst

David

Chas> And whatever became of Bubble memory?

I was

wait

Unions are a sore spot with me.

I worked at a unionized defense plant doing QA work which was a non union job. They were talking about striking when the president of the union told me she would slash the tires on my car if I came in to work. I smiled and told her I would gladly run over her in the parking lot if I saw a her with a knife, and that I was spreading the word about the threats. Soldering was a union only job there. The production supervisor went to my boss one night and asked if he could "Borrow" me for an hour or so. I went to the rework area and saw the ladies trying to solder the case of a large transformer to a circuit board used in the PRC-77. He told me they had spent four hours trying to do the repairs. The union steward was standing there glaring at me. I asked if I was allowed to show them the proper way to do the job. They agreed so I did the first one, then grinned at the production supervisor and said, I'm only going to show them one more time as I did the second one. The union steward tried to have me fired.

Several years later the IBEW tried to unionize the Cable TV company I worked for. They promised me $2 an hour less than I was making, three weeks less vacation and all for around $200 a month in dues. I told him the owner would never allow a union, and I wasn't going to lose $4160 in pay, pay another $2400 in dues and lose three weeks vacation that i could sell back to the company.

That was the initial claim, but it had high power usage, was slow to write. Then ram, rom and eprom came into the market which had lower power, lower and single rail voltages (except for the 2708 eprom).

Are you aware of any advances in electronics in the past 20-30 years? Have you been on a hiatus from electronics, and just come back into the field?

I saw one TI Pro computer (Early PC clone) with bubble memory. It was part of the billing system for a Cable TV office and was provided by the data processing company. the bubble memory was a joke. The data entry people would come in and turn on the computer to find out that the it wouldn't boot. Then the data processing service would send a tech to reload the memory and it would work for a few months, then die again.

I wonder if there are some bubble memory cores still available. Might be nice to play with, just as a nostalgic thing.

I haven't seen one for over 20 years.

Some Unions may have retards in them but if it wasn't for unions you would be working for peanuts in conditions that you wouldn't have animals living in. The problem is I guess that Unions have obtained as much as they are going to get in terms of conditions for the workers and they have to change but I would still prefer an outdated Union then none at all.

And yes you may get more money now without the union but without unions you wouldn't be in that position. People like you are just as bad as the unionist you describe ie. you cant see past the end of your noses