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1500 questions
19
votes
3 answers
Which retro system controllers are compatible with Amiga out of the box
I read an article that people were using various means of user input in their Amiga 500 computers as an alternative to joystick. Most notable, Sega Mega Drive, Sega Master System, CD32 / Competition Pro CD32. What other controllers are compatible…
Bartek Malysz
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19
votes
1 answer
Uninstalling OS/400 by deleting one program
This is about the AS/400 which is an IBM mini-computer launched in 1988. It lives on today after several name changes and considerable hardware and software changes. It is still often informally called the AS/400 but this is about the early days…
badjohn
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19
votes
2 answers
Is it possible to procedurally determine the number of cycles a particular instruction takes on a 6502?
Most emulators store the number of cycles a particular instruction takes in an array, and then adds any conditional cycles if needed (when crossing page boundaries, for example).
I'm wondering if there is a way to procedurally determine the number…
w.brian
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19
votes
6 answers
Can removing a cartridge from an NES (or any other cartridge-based game system) damage the hardware or software?
On some cartridge-based video game systems (NES, Game Boy Color, etc.) it is possible to remove the cartridge while the game system is still powered on. What kind of damage can this behavior do to the system hardware or game itself?
JAL
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19
votes
3 answers
When did files start to be dated?
When I revisit my files on a 5¼″ floppy using my 1541 drive with a C64 I mainly miss the date on files.
I know that a Real Time Clock was not implemented and that the first computer to integrate the RTC was the IBM PC/AT in 1984.
When did files…
Paul Ghobril
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19
votes
11 answers
What was the earliest system to explicitly support threading based on shared memory?
The notion of multiple processes has been around a long time, at least since the IBM 360. Multiple processes running at the same time, in separate memory spaces with protection from each other.
(In this context, I'm not talking about the distinction…
rwallace
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19
votes
2 answers
How did AMD's 386 and 486 perform like Intel's newer generation?
AMD really started to come into its own as a competitor to Intel around the time of the Intel 80486 introduction. AMD countered Intel by shipping the popular (at least with PC enthusiasts) Am386-40, which many have claimed performed as well as the…
Brian H
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19
votes
2 answers
How were 4-digit IC part numbers assigned?
It seems that integrated circuits of the 1970s tended to have 4-digit part numbers. This includes not only the ones that came to be well-known like CPUs (Intel 4004, 8008, 8080, 8085, 8086, 8088, Motorola 6800, 6809, MOS Technology 6502, 6507), but…
rwallace
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19
votes
1 answer
Detecting the external x87 FPU
On modern processors the x87 FPU is integrated in the CPU chip, but it used to be a separate chip before the 80486. So is there any way to detect its presence, and maybe even its generation (8087, 80187 etc)?
DarkAtom
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19
votes
12 answers
Did early assembly games use hardcoded memory locations?
In the era of C64, Apple][ GS, and SNES, did the games use hardcoded memory locations, or did they let the assembler help them (like modern assemblers)? If yes, how did they manage the memory?
Ignis Incendio
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19
votes
2 answers
Was there ever a Linux kernel driver for accessing disks via BIOS?
If there is some piece of PC compatible hardware where there are no (publicly) existing drivers for Linux, the only option is to access the disk with BIOS calls. I'm aware that this imposes restrictions on the maximum size of disk and/or partition…
PoC
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19
votes
2 answers
What are these weird long ISA slots on this 386 board? (not VLB)
In this image, you can see, from the right, a 16-bit ISA slot (occupied by a controller card), an 8-bit ISA slot, four more 16-bit ISA slots, and two of these strange slots that look like a 16-bit ISA slot, except with an 86-contact extension…
robbie
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19
votes
1 answer
How Did the 10NES lockout chip work?
One of the differences between the Japanese Famicom and the NES released outside of Japan is that the NES shipped with a lockout chip which prevented bootleg and imported games from working on the system.
How did this chip work? What kind of…
JAL
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19
votes
1 answer
How did the 6502 ALU perform a decrement?
Assuming that this diagram is correct:
Instructions like INC, INX, and INY can easily perform increment using ALU sum with data on B input, 0 on A input and carry_in set.
But how do instructions like DEC, DEX and DEY work?
It can decrement by…
Johnmph
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19
votes
4 answers
Why did some Spectrum games need LOAD "" CODE?
Most ZX Spectrum games were loaded from tape, and the traditional way of starting the loading process (at least in the 48K era) was to type
LOAD ""
and then start the tape. This would normally load a small BASIC loader, sometimes containing more…
KenD
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