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Why does the C64 have the following palette?
The Commodore 64 has the following fixed palette of 16 colours:
(Your palette may vary due to tuning of screen, etc.)
What was the reason for this selection of colours? Are these colours particularly easy to realise across a NTSC/PAL signal, or…
fhd333
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How did the Sideways address space work?
I was researching the BBC Micro when I found the Sideways address space: a 16KiB memory space allowing access to up to 16 16KiB external blocks of ROM (or RAM).
But 16 blocks of 16KiB is 256KiB, which is larger than the memory space itself! How did…
wizzwizz4
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Who were the first engineers to "cleanroom" the IBM PC BIOS?
In the first season of the AMC show Halt & Catch Fire, the protagonist "Cameron Howe" is introduced.
Cameron portrays a rookie engineer who is recruited for being extraordinarily talented, and is tasked by her new employer to perform a cleanroom…
Brian H
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Why did tactile-feedback keyboards lose popularity?
IBM spoiled me for hardware quality. I've gone through many computers, including a TRS-80, Heathkit H-89, Commodore Vic-20 and C-64, and countless PC's but my first original IBM PC will always be my favorite because of the sheer quality of the box…
Bill Hileman
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PDP-8 transistor count
https://en.wikipedia.org/wiki/Transistor_count provides some transistor count figures for early microprocessors, e.g. 8008 and 6502 both listed at around 3500.
The PDP-8 was a 12-bit computer with a deliberately simple instruction set. At first…
rwallace
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5 answers
Adding the third floppy drive?
I've seen a few computers with more than two floppy drives, most with two 3.5" and one 5.25". My question is how was this achieved? I've heard that it could be done with a second controller card, but I'm not aware about FDD controller cards for…
redsPL
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Replacing 80286 with 68000
Suppose you wanted to take a 286 PC and replace the CPU with a 68000, not at the initial design stage, but actually modifying the finished machine, on the theory that they both have 24 bits of address and 16 bits of data bus so it's not obviously…
rwallace
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Can a 16K computer be upgraded to 64K?
A slightly odd question, but is it possible to take an old 16K computer that wasn't designed for memory upgrades, such as a Commodore 16 or PET 4016, and upgrade it to 64K as a hardware hack?
I'm not a hardware engineer; here are my initial loose…
rwallace
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Reason for popularity of Apple IIGS
According to https://en.wikipedia.org/wiki/Apple_IIGS the Apple IIGS, in its year of introduction, outsold the Macintosh, without being substantially cheaper than it. This is somewhat counterintuitive: one usually expects that at close to the same…
rwallace
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PET space arcade game with surprisingly good graphics
We had PET computers in my high school, 4032's IIRC, and a few classic games to go with them - the excellent Space Invaders port, Star Trek of course, and a few others. These all used PETASCII for graphics, if any.
In my last year there I found…
Maury Markowitz
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16
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3 answers
The Tandy/TRS-80 Multipack Interface (MPI)
A popular, but, much maligned bus expansion device for the CoCo was the venerable MPI. There were several companies who made bus expasion devices for the CoCo, however, this question is related specifically to the Tandy version.
There were three…
Brian Blake
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Where did Fast InvSqrt() come from?
The fast inverse square root algorithm is probably best known for its use in Quake III Arena, the source code of which was released to the public a few years after its release. However, the algorithm was used much earlier than this - Wikipedia gives…
wizzwizz4
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Creating a new locale.library language support for AmigaOS
Looking through the LO (localisation) disk for Workbench 3.1, I see that the language files are binary. I'd like to create a Gaeilge (Irish) localisation file. How is this done on Amiga?
Update: Following Raffzahn's advice, LocaleTest provides…
TenLeftFingers
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What is the difference between the Commodore 1701 and the 1702?
Among the monitors offered by Commodore were the 1701 and the 1702, which, to my recollection, looked pretty much identical. Were there any cosmetic, functional, or other differences between the two?
Raymond68
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Speed of early ROM versus RAM chips
In the late seventies, up through around 1981, the maximum access speed of off-the-shelf RAM chips was around 2.6 MHz.
Did the same speed limit apply to ROM chips of the same era? If not, what would their maximum access speed have been?
Edit:…
rwallace
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