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1500 questions
41
votes
1 answer
How does the 68060 branch predictor work?
The 68060 had a branch predictor that improved the cycle count of branches that tended to go one way or the other. Apparently it did not handle branches that alternated or had some kind of pattern to when they were taken.
How did this branch…
Omar and Lorraine
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41
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4 answers
What's with the Atari 2600 colors on SECAM?
On this picture below you can see that the Atari 2600 graphics are rather colourful, and some games like Pitfall! I think use the many shades of each colour and have rather good graphics for the 2600. I have seen a video of that game on youtube and…
Omar and Lorraine
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41
votes
1 answer
Looking for a PC 2D platformer game from the mid-2000s or earlier
I'm trying to find the name of a PC game I used to play as a kid in the early/mid-2000s. All I remember from it is that it was a 2D platformer and that one of the levels looked like the following image:
I distinctly remember having to jump over…
RedForBlue102
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41
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12 answers
When did assembly source code begin to be written in lowercase?
In nearly all the assembly source files and published listings I read up to the early 1980s, the labels, mnemonics, and operands were written in all uppercase. Just a few years later, I noticed 80x86 code was mostly in all lowercase, as well as…
Paolo Amoroso
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41
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1 answer
How did the Amiga DCTV work
This is an unusual question since I'll answer it right away because it was a truly unique device and there is absolutely nothing about the technology it used on the internet. I spoke with the hardware designer, and for the first time we can…
Thomas
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41
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3 answers
80286 can switch from real mode to protected mode - but why not back?
It's been a while, but I've read in a system programming book that you could switch your Intel 80286 CPU from the normal real mode to a more powerful protected mode. I clearly remember that they said it was impossible to switch back though, unless…
Byte Commander
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41
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2 answers
Where and what was Haunt.bat? A game pre-loaded on a c1992 PC
This doesn't belong on the gaming SE, so I'm trying my luck here.
I'm looking for any info I can get on an old game that I simply known as "Haunt.bat".
Here is the back-story:
In the mid 90's a relative of mine purchased a PC.
I don't recall the…
Gorchestopher H
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41
votes
4 answers
Is it true that Pentium III was faster than its successor Pentium 4?
My friend told me that earlier iterations of the Pentium 4 were not as fast as the Pentium III, but he didn't have sources.
Is it true that the Pentium III was faster than its successor Pentium 4?
May Teresa
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41
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11 answers
What prevents faster versions of old architectures from being created?
Showing my ignorance about hardware here — I noticed there is still a community developing Amiga accelerator cards. Giving substantial boost versus the original memory for example.
However the processor frequencies, while faster, aren't…
ideasman42
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40
votes
4 answers
What determines the color of every 8th pixel on the Apple II?
On the Apple II there's an interesting way to add a little color to the bitmap, since the high bit selects the palette used for the three-and-a-half pixels represented by the byte. Like this:
0: Black, green, purple, white
1: Black, blue, orange,…
Omar and Lorraine
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40
votes
7 answers
Comparing raw performance of the Z80 and the 6502
A lot has been said on the internet about the 6502, at 1MHz, being roughly equivalent in performance to the Z80, at 4 MHz. It is said the Z80 has a typical 4 clock ticks per instruction, while the 6502 has typically 1 clock tick per instruction and…
Biff Iam
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40
votes
5 answers
Why (historically) include the number of arguments (argc) as a parameter of main?
A comment on this answer to a StackOverflow question made me curious. According the C99 standard, section 5.1.2.2.1:
The function called at program startup is named main. The implementation declares no prototype for this function. It shall be…
tonysdg
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40
votes
3 answers
Advantages of a Hitachi HD6309 versus a plain Motorola MC6809
Hitachi was a second source for the Motorola 6809 Micro Processor. The 6309 had many secret features. What advantages does the HD6309 have over the MC6809?
tlindner
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40
votes
5 answers
What's the origin of process return status 0 meaning success?
Why, usually, does 0 mean success in process return status codes?
When I worked at TANO Corp in New Orleans in the late 70s and early 80s, the convention there was the opposite: 1, true, was the "it's all OK", and 0, false, was "oops!"
Along all the…
Richard T
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40
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3 answers
What was the first operating system to be called an "operating system"?
According to Wikipedia, the first operating system was GM-NAA I/O, produced in 1956 by General Motors' Research division for its IBM 704.
According to Merriam-Webster and Etymonline, the term "operating system" was first used in 1961. (Neither…
hippietrail
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