38
votes
Accepted
What is happening in this algorithm scaling an 8-bit 0-99 value to full-range 16-bit?
Technically, this is just scaling, as quantization means a completely different process.
That's simply a multiplication, done with an algorithm which exploits the range of used numbers and avoids the ...
- 41.5k
32
votes
What "spectacular to watch" algorithms were used for sorting tapes?
Sorting on tape is actually mostly merging. And the canonical never-to-be-surpassed source of information on that is Knuth's masterwork The Art Of Computer Programming1 (aka TAOCP). Specifically ...
- 6,874
15
votes
What "spectacular to watch" algorithms were used for sorting tapes?
The fastest tape sorts were proprietary variations of polyphase merge sort that could take advantage of tape drives that could read backwards for 3 to 7 tape drives (for 8 or more tape drives, ...
- 845
15
votes
What is happening in this algorithm scaling an 8-bit 0-99 value to full-range 16-bit?
The algorithm is called "multiplication".
The code appears to compute A×2×165×2, which simplifies to A×660. This linearly maps the range 0–99 into 0–65,340.
I don't know the 6303, but ...
- 12.9k
13
votes
Accepted
How does the Atari ST's VDI polygon filling algorithm work?
The following is from Computer Graphics: Principles and Practice by Foley, van Dam, Feiner and Hughes. Considering that this text was the "bible" of computer graphics during the 1990s, I ...
- 17k
7
votes
Significance of compass heading values 4100-8200 in an old game?
I'm going to go out on a limb with a guess
You've told us what the numbers are and what the numbers are used for, but you haven't told us how they're used.
It looks like the bits are being used as ...
- 171
4
votes
How does the Atari ST's VDI polygon filling algorithm work?
I have accepted @DrSheldon's explanation as the answer to this question, and it gets at why a polygon fill routine may result in a different shape than what you would get by using Bresenham's line-...
- 291
1
vote
Significance of compass heading values 4100-8200 in an old game?
TL;DR: It's most likely noted in 'binary' decigon offset by 4096.
Why?
This is obvious by taking a few simple steps:
A Gon, also known as Gradian, parts a right angle into 100 equal steps, thus a ...
- 249k
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