manassehkatz-Moving 2 Codidact
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Original Mac clock frequency
10 votes

15.667 Mhz is about 2% less than 16 Mhz. So for purposes of "multiple of max. MC68000 frequency", it is close enough. The Mac wasn't competing based on being the fastest machine, so 2% was just not a ...

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Why was the shrinking from 8″ made only to 5.25″ and not smaller (4″ or less)?
10 votes

As Albert Einstein allegedly said “Everything should be made as simple as possible, but no simpler. The same applies to floppy drive size and many other things. There is a big difference between 8" ...

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What were the real competitors to the early IBM PC?
10 votes

Depended on the Size of the Business The Smallest Businesses and Individuals in Larger Businesses When the IBM PC first came up, the primary business uses were the same as any other standalone single-...

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How did Capcom make the decision to produce 1942?
9 votes

From Wikipedia: this was due to being the first Capcom game designed with Western markets in mind In a way, no different from many, many, many other products sold around the world in "hostile&...

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Were any IBM mainframes ever run multiuser?
9 votes

But were any of them used like the college-lab VAX, to provide a bunch of people with interactive shell accounts that could run arbitrary code? Absolutely 100%! TL;DR University of Maryland - ...

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Can I build a working(ish) vacuum tube byte?
9 votes

My suggestion would be to use relays. Still readily available, and while you wouldn't be using vintage parts, there were definitely some computers built with relays. Can't handle as high speed as well ...

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How to get Windows XP to detect a DB-15 gameport joystick?
Accepted answer
8 votes

It looks like you need to explicitly add the device - i.e., it isn't plug 'n play like USB or even like a lot of older devices (e.g., mice & keyboards on PS/2 ports). Microsoft: To install a game ...

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Why doesn't Nintendo fire up the old factories and re-produce *exact* copies of many of their most popular games, controllers and consoles?
8 votes

Cost While the actual design work is already done, it is quite possible that much of the production-related equipment - e.g., molds for cases and controllers - is long gone. If so, that would all need ...

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Why do PCs boot in 720x400 resolution?
8 votes

Most of the typical full color resolutions were based on 4:3 ratio - e.g., 640x480, 800x600, etc. - which matched the aspect ratio of broadcast television at the time. Using a 4:3 pixel ratio on a 4:3 ...

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What was the largest resolution supported by terminal escape codes?
8 votes

Tektronix (and emulated Tektronix) graphics mode Not exactly what you are looking for (because not "characters"), but Tektronix 4010/4014 mode as supported by Wyse 99GT and Wyse 370 (and I ...

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Largest practical motherboard for early computers
8 votes

There were some large motherboards. However, a LOT of computers relied on daughterboards to carry the load. In the case of S-100 machines (from the original Altair on up) the CPU was simply one of ...

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Were the 80s more educational on IT?
Accepted answer
6 votes

Warning, Subjective & Location-based This is a poor question in two ways - it is both subjective (how do you "value" learning about different computer languages, different types of ...

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What are the sizes of the hex nut drivers in the classic "nine piece" computer toolkit
Accepted answer
6 votes

I believe you are referring to one of these: This one is actually an 11-piece. But same basic stuff. I've used & lost quite a few of these over the years. According to the specs: Includes ...

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8086 pinout and address space limit
6 votes

Total System Cost = RAM + CPU + Everything Else When you are going for the mass market - as opposed to workstations or other high-end systems - the key is total system pricing. Three of the biggest ...

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When did smart terminals arrive?
6 votes

Arguably the prototypical smart terminal was the IBM 3270. According to this link IBM History the 3270 was first demonstrated on May 23, 1971. While the Intel 4004 was shipping already at that time, ...

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What was the most common method of internet access for small offices in 1990s in USA?
5 votes

In most places, it was dial-up until ADSL. I had two customers with ISDN for a while, both replaced with ADSL when available. One was sometime in the late 90s until 2003, the other roughly 2003-2004. ...

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What did order processing on a teletype look like?
5 votes

A few pieces: Why does one so often hear of payroll, specifically, being an early application of such systems? It seems to me this is partly because the payroll of a big company involved a lot of ...

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CPU slaves on a PCI card to retrofit single processor to multiple processors. Any ideas how?
Accepted answer
5 votes

CompuPro did this in the olden days, with 8-bit and 16-bit CPU slave cards with a 16-bit or 32-bit main CPU. But there were a few differences from what you are suggesting: Each CPU had its own RAM. ...

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Why did the SWTPC 6800 Computer System not take off?
5 votes

I strongly suspect CP/M was the key. Plenty of 8080 (and by extension, Z80) machines ran other operating systems, particularly the Radio Shack TRS-80 line. But the basics of Altair, Imsai, Osborne, ...

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Why were "data modems" so much more expensive compared to "fax modems" back in the day?
5 votes

There are actually a few slightly different pieces of hardware involved. As a starting point though, note that for many years the price of a standalone fax machine, essentially a high-speed (for the ...

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First appearance of the Sieve in Byte *as a benchmark*?
5 votes

Not exactly what you are looking for, but meets the technical statement of "a pointer to the first appearance of this code as a benchmarking tool in that magazine" and is earlier than Stephen Kitt's ...

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Parallel to serial conversion
5 votes

This is only barely Retrocomputing. Almost all the printers I use today (and most people I know) are connected USB or networked. But ports for PCs are still available and as noted below, the companies ...

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Did terminals (e.g. VT100) require a terminal driver on the host computer?
5 votes

Two more slightly different situations from the past (well, everything in Retrocomputing is from the past...): 3270 Emulation When I was at the University of Maryland, College Park in the early 1980s, ...

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What was the typical thickness of fanfold printer paper?
5 votes

In the US, paper is normally measured in pounds (lbs.) with the actual measurement defined a little differently depending on the type of paper - "cover", "text", etc. That is a very long discussion, ...

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Did the BBC ask for any unusual key colors on the BBC Micro?
Accepted answer
4 votes

From a previous question: What BBC Microcomputer features were requested specifically by BBC engineers? which references this BBC document: both pound sign and number symbol (hash) must be ...

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Where was this Grace Hopper/Univac photo taken?
4 votes

Could be "anywhere". But my guess would be a US government facility, more likely DOD, and most likely of all Navy. In addition to Admiral Grace Hopper, Donald Cropper according to this obituary if I ...

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Why did mainframes have big conspicuous power-off buttons?
3 votes

Stop A Big "Oops" While I suspect that, short of national security situations (like say shutting off WOPR before it launches a first strike), mainframes were not deliberately shut off to ...

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Single-stepping the Altair 8800
3 votes

From the Altair 8800 Theory of Operation Manual & Schematics 1975: The Single Step circuit consists of a dual single shot (IC M) for debounce and the SGL STP flip-flop (R-S type). When the ...

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Was Unix ever a single-user OS?
3 votes

From this page, Wikipedia and elsewhere, it is pretty clear that the first Unix system was on a PDP-7. As far as I can tell, the PDP-7 (unlike the PDP-11 where Unix became more than just a one-off ...

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Compile the 6502 assembler source code for running on modern computers
3 votes

As with so many things, maybe. Assuming that "Assembly 6502" is a full 6502-compatible assembly language: If you assemble an entire bootable image and burn it into an EPROM (or equivalent) and ...

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