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1500 questions
30
votes
2 answers
Process model in early UNIX
I heard recently that the process model in very early variants of UNIX was quite a bit different to the fork/exec model used nowadays.
How did it differ from the current state?
user6464
30
votes
3 answers
How does Space Invaders on the Atari 2600 display all the aliens?
The Atari 2600 has two 8-bit wide player sprites, and it appears to be these sprites which are used to draw these aliens.
There are a few different ways to produce many copies of one sprite; controlled by nusiz0 and nusiz1. If you don't want the…
Omar and Lorraine
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30
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5 answers
Why were early personal computer monitors not green?
Green was traditionally the most common color for computer monitors; it combines strain-free readability with low cost.
Given this, it's surprising that the first versions of the Commodore PET and TRS-80 came with bluish-white monitors, though…
rwallace
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30
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5 answers
How was microcode implemented in retro processors?
How was microcode implemented in retro processors such as the Z80 or 8080?
Was the microcode standard (for example a manual for the processor outlining all possible micro-instructions and the standard combinations to implement documented…
Jet Blue
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30
votes
7 answers
How can you run a program that is bigger than RAM?
Suppose you have a program that is 218 words long. However you are using a 16 bit machine and have 216 words of RAM. (The RAM is directly addressed by the CPU). On the other hand, you have unlimited 'slow' storage where the full program can reside.…
Jet Blue
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30
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5 answers
Are MS-DOS and Windows 9x vulnerable to Meltdown?
In an interesting crossover between current events and Retrocomputing, the vulnerability known as "Meltdown" was publicly disclosed on January 3rd 2018. The retro-computing tie-in is that this vulnerability is reported to impact all Intel…
Brian H
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30
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4 answers
Absolute maximum number of nibbles on an Apple II floppy disk track?
The Apple 2's disk drive controller and 5¼" floppy disks have the following metrics:
The disks is spun at (roughly) 300 RPM (Revolutions per Minute), which means it takes = 1000 ms/sec / (300 RPM / 60 sec/min) = ~200 ms / revolution,
Beneath Apple…
Michaelangel007
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30
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2 answers
C64: Why is POS(π) faster than POS(0)?
According to this article: german C64 Wiki article about the POS() command POS(π) is 20 % faster.
Although in my experience it is circa 28 % faster.
…
user6734
30
votes
3 answers
Why did 1990s-2000s LCD all use 60 Hz refresh?
In the CRT era, refresh rates ranged from 50 to 160 Hz. Some displays could barely do 65, high-end Mitsubishi and Sony tubes could run 120+; most people used 70-100 Hz. GPU DACs and monitor circuits were hard to scale past ~180 MHz pixel clock,…
Therac
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30
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4 answers
How did the X-Men game for Sega Genesis have its state survive a console reset?
The Sega Genesis system had a rather interesting game. X-Men (1993) was based on the popular cartoon version of the comic book series. But it had what was still one of the most unique (and unintuitive) mechanisms I've ever heard of. In the second to…
Machavity
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30
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3 answers
Most modern C compilers targeting DOS 8086, running on DOS 8086 (16-bit)
I'm looking for the most recent versions of modern C compilers which were/are targeting DOS 8086, also running on DOS 8086 (16-bit). I'm mostly interested in production-ready C compilers, rather than hobby projects (possibly many bugs yet to be…
pts
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What exactly did the "UNFORMAT" MS-DOS command do?
I found only this:
The UNFORMAT command is used to undo the effects of formatting a disk.
The command is available in MS-DOS versions 5 and later.
Source: https://en.wikipedia.org/wiki/List_of_DOS_commands#UNFORMAT
It's also considered important…
P. Molet
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30
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10 answers
What happened to all those Unix workstations in the '90s?
Around the early to mid '90s it seems there was a trend for high-end workstations running some form of Unix, and running a RISC or at least some kind of non-x86 architecture. For example:
Sun SPARCstations
NeXT workstations
SGI workstations
HP…
Meatwad
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30
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3 answers
Why did Nintendo name its console the "Famicom"?
The NES was known as the "Famicom" in Japan, short for "Family Computer".
But why was it given an English name in Japan, given (I assume) most people wouldn't know what the words "Family Computer" meant? Why did they not give it a name in Japanese?
komodosp
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1 answer
Why did Nintendo 64 (1996) memory cards require a battery inside them to retain data whereas the PlayStation (1994) ones did not?
The Nintendo 64 was released in 1996. Its "Controller Pak"s, which was the name of the memory card that you put inside the controller to save the progress in certain games, require a battery for them to retain the data. It can be seen in this video:…
Jacon
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