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54

R&D stuff isn't manufactured (at first). It's usually partially constructed, ripped up, and redone, multiple times, with long testing and debug cycles in between, all the while with payroll running up the tab. Tons (literally) of fried or used components and partial assemblies can go into the junk bin. The specifications then often evolve with the ...


26

So what was the other $478,000 spent on? Paying people to design and build it would have been a fairly big component. People often underestimate the cost of labour, particularly if it is their own time. Also looking at the photos of it on wikipedia, there were a lot of components besides valves. There were racks and other cabinets and what looks like a ...


22

One of the biggest factors is that when you have a machine that requires 5,000,000 successful solder joints to function properly, you need to make sure that all of your solder joints are really really good. If 1 in 10,000 of your solder joints is subtly bad, that means that the first time you try to put everything together you will have 5000 bad solders and ...


11

I've tried to find information when term 'word' was firstly used. And it seems that even ENIAC used this term. And before it, Zuse used it to describe the words of his first machine. Is it safe to say that term 'word' was invented with ENIAC? Does it need to be invented? Or isn't it rather obvious? A word is simply the next structure level after a single ...


8

Removable plugboards were a common form of read-only memory which I think fits the criteria. ENIAC plugboards were not removable, but later computers used low cost removable ones. They were adapted from the plugboards used for unit record equipment, which were simple frameworks for holding programming wires. An installation would have many of them "...


8

Here's a video about manufacturing UNIVAC 1108 (circa 1965, so a bit later but still illuminating). Notice how much is done by hand, even things like winding coils. According to the University of Minnesota the UNIVAC division employed about 10,000 people. Price list for some UNIVAC 1104 components (long page of text, search for "UNIVAC 1004 PRICE LIST&...


6

But I'm used to a flip-flop being made of six transistors, which suggests it would need six triodes, Not really, a basic flip flop does not need 6 transistors. maybe there's a mix up with RAM cells? Two will do it quite fine (*1,*2). Similar the two triodes of a 6SN7 is all what's needed - well, plus two rather equal resistors between them and another two ...


6

It's necessary to consider the standards of the time the machine was named, and its original purpose, which was calculating ballistics tables for the Ordnance Corps of the US Army. It replaced 200 people using mechanical calculators, and was faster and more accurate at that work. So what seem like very basic functions for supporting numerical integration now ...


3

There are a number of possibilities, though most of them involve stretching the definition of "computer" somewhat: The Zuse Z1, Z2, and Z4 computers used slotted metal strips as memory. Of these, only the Z4 was Turing-complete. The Harvard Mark I and Mark II, the Zuse Z3, and BARK all used relays for storage, but only the Z3 was Turing-complete. All of ...


3

I think core memory is what you are looking for. You may not think of it as a mechanical solution however it was. Core memory is electrically set and read, the read is destructive so part of the read initiated an automatic write if the bit was a 1. Core retains its state after power loss through the mechanical position of the magnetic toroids. If at power ...


2

A conventional flip flop requires the following: Two inverting switching elements that will strongly pull their output in the direction opposite what's required to turn them on. Two elements that can weakly pull the output of whichever switching element isn't on in the opposite direction. Two elements that, in response to external stimuli, can pull those ...


1

The Zeus Z1, Zeus Z2, and Zeus Z4 used "mechanical slotted metal strip memory". These were not stored program computers where the program is executed entirely out of main memory; rather, then program was read from a punched tape reader (Z1 and Z4) or punched card reader (Z2). The memory was used primarily for data, but it was randomly addressed. ...


1

This is an edited and expanded copy of an answer I posted elsewhere; it was pointed out to me that it would be useful information here. EDSAC (operational in 1949) had read-only memory to hold its Initial Orders. The Initial Orders were wired on to uniselectors, otherwise known as stepping switches. The EDSAC had hardware facilities to load the Initial ...


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