96

The basic issue that paper tape is hard to edit. In theory you can cut the existing tape and splice in a new section, but in practice there is no easy way to find the correct location except by printing the contents of the tape (at 10 characters per second) and searching by hand. People did learn to read the tape hole patterns (they were no harder to learn ...


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 ...


41

Specifically concerning EISPACK. what happened was that James Hardy "Jim" Wilkinson in the UK (whose career as an applied mathematician started with practical ballistic modelling in WWII, working with Turing and other computing pioneers, and continued for the rest of his life at the UK National Physical Laboratory, not in some academic ivory tower) ...


37

Punch cards long long long predated paper tape. But there's a practical consideration you're not thinking of. If you had ever used punch cards and paper tape, you'd know: Punch cards can be dropped, and they scatter on the floor. Then you pick them up, put them all face up (by the printing on them) in the same orientation (with the one corner that's cut ...


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

The world of large computers is amazing. MCM systems of monstrous in the eyes of a PC user parameters were widely popular right up to the cloud revolution, and even now, taking into account legal restrictions, they are actively used in banks. Just remember IBM POWER2+ in a six-chip configuration for one core (not counting L2 cache) (video) - it was launched ...


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 ...


17

Wikipedia, unsurprisingly, gives incomplete information. A number of important new technologies were developed as part of the five-year R&D of SABRE, including a disk drive capable of storing that many reservations, a new transaction-processing system, a frequency-modulation system to send data over the phone lines, and a new model of terminal, pictured ...


16

The information to answer the question "exactly" is available on the internet, but I'm not going to do the arithmetic for you! The Maintenance Manual (http://bitsavers.org/pdf/cdc/1604/033a_1604_Computer_Vol_3_Maintenance_Dec60.pdf) Appendix B gives the schematic of each printed circuit card, so you can count the number of transistors on each. The ...


13

That question is rather wide, as there wasn't a mainframe OS but many. Equally important, headers were not made by the OS, but whatever SPOOL system was used. And there were many. Here a typical MVS(ish) cover page: Depending on organisational structure of OS and SPOOL-system a cover (or SPOOL) page may include: Job Name User Name Account Number These ...


13

Make your way to Palo Alto, California, and find the Xerox PARC facility. Do whatever it takes to get a conversation with Alan Kay. Admittedly, you don't know any Smalltalk, but neither does anybody else. Your ability to think in terms of a collection of software objects interacting with each other will impress the hell out of him. He'll get you a job ...


12

Punch cards and paper tape are suited for different tasks. Punch cards work better when the size of the data is not known in advance. How long would you manufacture the unpunched paper rolls? If the roll is too long, you are wasting paper and increasing costs. If the roll is too short, you either have to splice it together, or have the operator load more ...


12

The HP-3000 first introduced in 1972 was a 16-bit stack-based architecture that included an XEQ instruction that would treat a word on the stack (between TOS and 7 words below that as selected in the instruction) as a regular instruction and execute it. This was utilized in some calling conventions where you needed to execute a different version of the EXIT ...


11

Intel Itanium, aka IA-64, has 82-bit floating point registers. These are intended to preserve accuracy in intermediate values, but storing them into memory without loosing that accuracy is expensive: they occupy 16 bytes of RAM. The x87 floating-point registers on ordinary x86 CPUs can handle 80-bit values, but those were intended for use with 80-bit ...


11

To add one more dimension to the answers already given: cards are easier to handle, whether by operators, or in a cafeteria (user self-service) system. A high-speed card reader has an input hopper and an output stacker. After reading a deck of cards, you've got a deck of cards in the stacker. The high-speed paper tape readers of my acquaintance would do ...


11

Wire Wrap as used in computers is simply a later development then the ENIAC or vacuum tubes in general (*1). The Keller tools were first marketed in 1953 and it took a few more years until they made their way from telephone to computers. IBM might have been the first, around 1960, a bit before the /360 came which, used it a all over. *1 - In contrast, PCBs ...


11

The whole claim seems a bit dubious. I did spend a few hours now, not only searching the net, but as well peeking into all secondary literature I have regarding ICL (or parts thereof) and IBM, but couldn't find any remark even remotely supporting the claim. Over all it seems like an easy to make, hard to prove statement, especially as all, as mentioned, is ...


10

But in between those [Batch vs. Terminal], there was an era of 'interactivity, but not as we know it', when computers supported interactive work by teletype. Not really. To start with, these were complete different usage scenarios. Batch didn't turn into terminal use - or got replaced by it. Batch is like mass production on industrial scale. It still ...


10

The last commercial non-integrated main processor introduction that I can recall was the one in Tandem NonStop Cyclone systems, introduced circa 1989. The CPU seems to have been 3 large printed circuit boards full of ECL gate arrays.


10

What I'm wondering is: why punch cards instead of paper tape? Because it was already there? Early commercial computers were made to replace tabulating machines. To do so they had of course to be able to read (and write) punch cards. There was no need for paper tapes. Well, ok, paper tape was first, as the Zuse machines used them and some other experimental ...


10

[Just some quick notes from memory - after all, describing several related terminal families spanning over several decades might be a bit broad :))] That sounds similar to the IBM 3270, where the idea was to offload some of the work from the mainframe, so that instead of interrupting the mainframe on every keystroke, you only present it with a complete form....


9

If you want to know exactly how big the classic 1960s and 1970s IBM mainframes were, see the System/360 Physical Planning and System/370 Physical Planning guides. They give complete measurements of every part of the system. Consider the IBM System/360 Model 85, a large (but not the largest) mainframe from 1964. The processor itself took up 12 refrigerator-...


9

This answers your question by suggesting some avenues of further research. This is one of those cases where just knowing the right buzzwords helps with the search. You could start by doing some research on Fernando Corbato and the Compatible Time Sharing System (CTSS) for the IBM 7090/7094. This was one of the pioneering projects in timesharing. You could ...


9

TL;DR Too complicated for not much benefit. You ask why not include an execute instruction. The reason is quite simple. Since around the time you observed the absence of this kind of instruction, the CPU's got more and more optimized in their memory access. Code access was separated from data access as the access pattern are quite different. To execute a ...


8

The VAX 9000, first ship 1990, must be a contender here. Per Wikipedia, Each CPU was implemented with 13 Multi-Chip Units (MCUs), with each MCU containing several emitter-coupled logic (ECL) macrocell arrays which contained the CPU logic. By the time it was released, the 9000's price/performance had been eclipsed by systems based on NVAX, a single-chip ...


8

After all this time, perhaps I should attempt to answer my own question. It appears to have been a feature of the IBM 700-series of scientific machines, as described in Buchholz's paper, and of course was replicated in their transistorized descendents, the 70xx. I haven't found any similar approach, so until contradicted here (which I actively invite), I'll ...


8

what was the last central processing unit made commercially available that was not on one chip? The 8-bit discrete logic processor kit! It is commercially available now (you can buy it from the website above). It is multi-chip since it's made of 74LS chip. And... it is definitely retro.


8

Yes. Sort of. The KDF9 had an accumulator stack (the 'nesting store' or nest) which was mostly made of fast (1µs read, 1.5µs write) core - the top 3 elements were in fast registers, with 16 words of core underneath. Arithmetic was done on the top elements of the nest, popping off operands and pushing the result in the usual manner. Though the top cells were ...


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&...


7

As comments have suggested, it was quite a bit like other smart terminals such as a VT-100. The terminal had an RS-232 connection to the mainframe. But (at least as of the Plato V) it also have an 8080 in the terminal, with its own 8-bit expansion bus, so in many ways it was similar to something like an Apple II or TRS-80 (etc.) with a serial card--able to ...


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