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1500 questions
61
votes
2 answers
What is the "two-drive trick" that can read Amiga disks on a PC?
Standard belief is that the floppy disk controllers used on PCs are incapable of reading Amiga floppy disks, due to the PC disk controller expecting a very specific low-level format of disks, whilst the Amiga disk controller is much more flexible…
Richard Downer
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60
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7 answers
Did any compiler fully use Intel x87 80-bit floating point?
There is a paradox about floating point that I'm trying to understand.
Floating point is an eternal struggle with the problem that real numbers happen to be both essential and incomputable. It's the best solution we have for most calculations…
rwallace
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60
votes
4 answers
Why did F1 become the Help Key?
There was actually a pretty big push among some vendors in the 1980's to have a dedicated Help Key (conveniently labeled as Help). Atari introduced it in 1983, and kept it to the end. The Commodore Amiga had it from the A1000 onward. I'm sure there…
Brian H
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60
votes
4 answers
Why were single quotes ('…') chosen for characters, and double quotes ("…") for strings?
In C, '' is used to denote a character, while "" is used to denote a string. Why was this syntax chosen?
I tried to research this using Wikipedia’s Timeline of Programming Languages along with Rosetta Code’s reference page for strings. It seems that…
hb20007
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60
votes
8 answers
Could we have avoided the whole UTF-16 fiasco?
Anyone who has studied Unicode and is honest will admit that UTF-16 was kind of a mistake. It was born from the early assumption that 16 bits would be enough for all of Unicode. Then a hack was invented to extend it to 21 bits using "surrogate…
JoelFan
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59
votes
13 answers
How big is a mainframe?
If you read about the history of computing, you'll hear how the first computers were "huge". You will often come across assertions that in the early days of commercial computing, a single computer would be "so big that it filled an entire…
MathematicalOrchid
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59
votes
3 answers
Does this 8088 code in the Leisure Suit Larry 2 game actually do anything?
In the Sierra On-Line game "Leisure Suit Larry 2" there's a part in the game where the main character (Larry) has to write a program in 8088 assembly language as part of his tribal initiation. Larry then jokes that he's written a multi-user…
Noel Whitemore
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59
votes
7 answers
Origin of "string"
When did people start referring to an ordered group of characters as a "string"? Did this name come from before / outside of the computing field, or is it special to computing?
The metaphor is clear enough, I suppose: the characters are "strung…
John Skiles Skinner
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59
votes
7 answers
Why do old games use flashing as means of showing damage?
When you play old games, especially platformers, a common "special effect" is rapid blinking of your character when they are hit. Also, enemies often blinked before dying. Not all games did this, but it was very common, to the point in practically…
Vilx-
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59
votes
9 answers
What was the rationale behind 36 bit computer architectures?
Was there some particular design theory or constraint that made a 36 bit word size attractive for early computers? As opposed to the various power-of-2 word sizes which seem to have won out?
Mark Harrison
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59
votes
4 answers
On DOS computers, what would the PARK command do?
In 1994 or so, we had an old computer at my primary school. I remember finding out that it had a park command. From reading its documentation, it said that this command should be executed prior to shutdown. At home I would simply switch off when…
gerrit
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58
votes
17 answers
Simplest system to create an emulator for
Next year I'm going to teach a 2-semester microprocessors class to third-year undergraduate EE students. In order to sign up for the class, students need to have completed programming and digital systems classes.
In order to motivate the students…
swineone
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58
votes
2 answers
Why did Commodore fill their power supplies with epoxy?
If you know anything about the Commodore 64 (and other Commodores, really) you know that Commodore really went the cheap route and produced some awful power supplies. The Commodore 128 PSU isn't quite as bad as the C64 version, but it's nowhere…
cbmeeks
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58
votes
2 answers
What is this large device labelled 'Telefunken Datenspeicher' and how does it work?
We found this device in our school. Does anyone know what this can do exactly, and how it could work?
We managed to input values into the bit storage on the top, but nothing more. Can we calculate things by using the registers?
It would be already…
Poldi
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58
votes
4 answers
Why is slash so commonly used in old systems' abbreviations?
Many things around the '80s or earlier use ‘/’ in their abbreviations and sometimes even in their names, for example
IBM PS/2, OS/2 and PS/2 port
CP/M - MP/M - PL/M - PL/I - PL/S - PL/8 along with CP/NET, CP/NOS, MP/NET and MP/NOS
OS/8, MS/8 and…
phuclv
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