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42

I researched this question online fairly thoroughly a while back. I could not find any reference to an AGP device that wasn't a graphics card. It wasn't exhaustive, and absence of proof is not proof of absence, but I strongly suspect no such cards were made. I also think there are technical and economic reasons that make it unlikely. It would have been a ...


40

Several CPUs were considered. Essentially all 16 bit CPU of the time: TI's 9900, Motorola's 68000, Zilog's Z8000 and Intel 8086/88 This IEEE Spectrum article sheds some light on the development, at least for 68k, 9900 and 8088 (*1,*2). In the end,it came down to a combination of factors: TI's 9900 was single source, IBM didn't want a lock in. Motorola's ...


37

The floating-point routines for Microsoft BASIC were written by Monte Davidoff in 1975, originally for the Altair, which used an Intel 8080 CPU. The source code had been lost for years, until Bill Gates’ former tutor discovered a copy in 2000 that had fallen behind his file cabinet two decades before. Davidoff needed to invent his own floating-point format, ...


36

Colon was inherited from SOS for the Apple III Unlike one may assume, MacOS (1984/01) did not inherited the colon (:) from Lisa OS (1983/01), which used a hyphen (-) as path separator, but from Apple III's SOS (1980/10), created for the Apple III to manage the huge data pile of a 5 MiB Profile. Staircase wit: On colon vs. slash, Apple went not once but ...


36

Yes, huge safety concerns as I remember engineers sitting inside the cabinets of large mainframes while it was running, fully powered, large currents in each cabinet powering fans. Cooling water being pumped through the frames. Huge wiring looms hanging across the floor to great logic analysers on wheeled trolleys; trip hazards. One person regularly smoked ...


32

Yes. There were CP/CMS and VM/370 - true multiuser operating systems running on the mainframe with individual users logged in. AFAIK it was mainly used for software developers (to develop IBM mainframe software). I had the pleasure working on VM/370 once. Not what you'd call an ideal development environment. You got storage allocated to you: A certain ...


31

As far as I am familiar with the genesis of the IEEE-754 floating-point standard from the literature, G. W. Stewart never looked at implementation cost for the support of gradual underflow. He was tasked with examining its claimed advantages to floating-point computation from a numerical analysis viewpoint. Charles Severance, "IEEE 754: An Interview ...


25

One reason that has not been mentioned is that the memory and speed of the PC placed it in the ballpark of CP/M systems rather than UNIX systems (already available at the time). At this time there was a reasonably thriving market of CP/M office systems, and in spite of almost all of them being run by variants of the Z80 processor, much of the application ...


25

The original Macintosh File System did not support directories. But the Mac did support multiple floppy drives from the start, and colon : was used in fairly standard fashion as a drive prefix analogous to VMS, MS-DOS and elsewhere – Disk:File. This is only an educated guess, but I suspect they generalized : to a path separator later with HFS as it was ...


24

I believe that your presumption is incorrect: The vendor, having no way of knowing whose fault this is, has to take the machine back and try to debug it. The vendors did not have to take the machine back and if they did offer a repair service it was not free. I don't recall that MITS (vendor for Altair) offered a repair service but I know that Heathkit ...


23

It didn't move anything. There is no ROM at the beginning of memory. As the system did not include any code in ROM at all by default, ROMs were optional and usually placed at the end of memory. ROM is not needed, because the front panel can be used to halt the CPU, enter a program into RAM without CPU intervention, and command the CPU to execute the code ...


23

Back in the 80s, it was an industry and market very different from today's PC world. The audience were mainly do-it-yourself people who wanted to create things, and to understand how they worked. So, of your suggestions, "Tradition" best captures that aspect. You'll also find that, in line with that mindset, writing individual programs was a main ...


23

I think the colon deserves to be considered the original, the one true separator character. All others are mere imitators ;-) My rationale for this is the seminal paper A General-Purpose File System For Secondary Storage which first laid out the conceptual design of a tree-structured file system. It used ":" to separate components in path names (...


22

The TIA was designed by Jay Miner while he was working at Atari. I'd be very surprised if Atari did not hold whatever rights could be held. That being said, the rights that could be held to an IC design at the time were much more limited than they are today. Before the Washington treaty of 1989 and TRIPS, ICs were protected only by patents, not by copyright, ...


20

Using a 32 bit signed mantissa and 8 bit unsigned exponent has one major advantage: You can re-use 32 bit integer math functions for operating on the mantissa. That re-use saves memory. It may even be possible to optimize the 8 bit exponent maths if character maths are supported, as characters are typically stored as 8 bit unsigned ASCII. The original ...


19

IBM mainframes are still around (IBM Z). Linux has been available for IBM Z hardware and its predecessor, System/390, for 20 years, and z/OS is itself a certified UNIX through the z/OS UNIX System Services. Which is to say that IBM mainframes have been run in UNIX-like multi-user fashion for two decades by running UNIX. Apart from that, z/OS and its ...


18

It starts with discussion about computers overheating, That discussion seams to include some quite vague memory, so I wouldn't put to much into here. Still, such buttons were available and even installed after market, depending on company or state regulations. A CRAY Y-MP EL used at TU München is a great example, with its big power off: (Picture taken from ...


17

TL;DR: Which components or facilities were the biggest obstacle to porting typical COBOL applications? Simply that there were not many applications that made sense to be ported to (desktop) micros. If at all, downward migration of whole applications was toward /3x systems and ultimately AS400. Which was well supported and rather painless. <RANT> ...


15

It's not a power of 2, not a nice round number But it is :-) 1 byte exponent (with an assumed 1 bit always equal to one), 4 bytes mantissa, at least on the ZX Spectrum – see the ZX Spectrum manual. And since the mantissa and exponent are processed individually, the mantissa is a nice power of 2. Granted, this is less of an advantage without full 32 bit ...


15

Another one to mention is MTS which was first released in 1967, last release in 1988. It was in use at Rensselaer Polytechnic Institute from 1976 to 1999, of which I took part during the early 80s. In 1984 they were running it on Sybil, a dual processor IBM 3081D; slightly before that it ran on Myron, which I think was a 3070 but I'm not sure. There were a ...


14

Yes, because it did not provide the necessary connections for wider use AGP had asymmetric bandwidths. It was very much faster in transferring data from the CPU to the graphics card. For transferring data back from the graphics card to the CPU though, it was no faster than a PCI slot. For graphics cards, this is exactly what you need. You typically do not ...


13

if every machine will be sold preassembled, the vendor can invest in things like wave soldering equipment that can do the job much more efficiently than a user doing it once on the kitchen table I think this is a key point. Back in the 1970s, you did not have the super-cheap build-it-in-China and ship extremely inexpensively that you have today. Container ...


13

COBOL applications have not typically been ported from mainframes to micros because they rely on two features that micros typically lack. Throughput COBOL applications often need to process large amounts of data in a fixed amount of time (e.g. processing a day's sales data for all stores in a chain). These tasks are typically I/O bound and mainframes have ...


13

It's not completely accurate to focus on slashes as the established solution — . was also in the mix, being DEC's choice for both TOPS and VMS. That said, I'm going to speculate wildly that it comes down to: Apple's Macintosh filing systems were already fairly non-standard — supporting forked files, for example — in support of simplifying the user ...


12

As Wikipedia says (S-100 bus): "(Author) then looked for an inexpensive source of connectors, and he came across a supply of military surplus 100-pin edge connectors. The 100-pin bus was created by an anonymous draftsman, who selected the connector from a parts catalog and arbitrarily assigned signal names to groups of connector pins." So the ...


12

Many early computers were sold as self-assembly kits Not really. They were only more visible than the ready made machines. Kits were simply the best way to fill pages of magazines - and that's what most people saw and still find on the net - thus they got more 'screen time' than ready units. Especially early on, when there were no (semi-) professional ...


12

It seems that integrated circuits of the 1970s tended to have 4-digit part numbers. Not really. Anything from letters to numbers and 3 to 7 characters have been used. even with numbers like 7400, the chips name wasn't just the number, but a letter number combination, like SN7400. Other than often assumed is SN not a prefix used to indicate TI, but the '...


11

Simply put, for most of the PC's history, either the components were roughly uniform in their power consumption (with the major offenders typically being the 12V motors in disk drives, rather than anything solid-state), or the CPU was the major power consumer and thus source of heat. Only fairly recently has one particular type of expansion card, namely the ...


10

Suppose one is considering adding something to the specifications of a car that will, on 1% of units manufactured, extend the time required to perform some fabrication step by ten seconds. How much should that be expected to affect the cost of a car? If cars are being assembled individually, the extra cost would be trivial. An average of 0.1 seconds per ...


10

A number like 1234.56 takes three bytes in BCD where it would've taken eight bytes in double precision binary floating point. Generally speaking, that is not the case. If you have a database field definition of 6 digits total, 4 before the decimal, 2 after, positive numbers only, then yes you can have 1234.56 represented in 3 8-bit BCD bytes. But if, as is ...


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