Questions tagged [compression]

For questions about compression. May refer to lossless or lossy compression, and may refer to algorithms or utilities.

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Compression techniques used in old ZX Spectrum tapes

Many ZX Spectrum games* (and demos) would improve loading time and save space in the tape using rudimentary compression. During decompression, the game would display "decrunching" for ...
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0answers
395 views

What is the origin of executable compression?

According to the wikipedia article on the topic, the earliest executable compressor listed is Realia Spacemaker for IBM PC (since 1982, written by Robert B. K. Dewar, SM.COM, signature "MEMORY$&...
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What data compression did Donkey Kong Country use?

Donkey Kong Country was among the most ambitious, popular and influential of Super Nintendo games. Technically, its big trick was taking animations rendered on Silicon Graphics workstations and ...
5
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1answer
161 views

What was the first database to start compressing in situ?

The obvious way for a database to store data is with each record in a contiguous chunk, and each field having a fixed size and offset in the record. Joel Spolsky praises that way of doing things: ...
6
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1answer
300 views

Reconstructing uncompressed program from compressed tape image

I have a C64 program in a .t64 file. If I load it into an emulator, what I see is that it loads into a cracktro, which then proceeds to uncompress (taking several seconds at 100% speed) the original ...
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3answers
239 views

How do I interpret these instructions for decompressing game data? [closed]

I'm trying to write a tool for the 1994 SNES game Super Metroid that creates "out of bound" maps for each the game's rooms. To do so, first I need to extract the tile-by-tile data of each room. For ...
5
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2answers
966 views

Could early nineties PCs access raw CD bitstream?

In the early nineties, as discussed in What specific technical advance(s) allowed PCs to play "Full-screen full-motion" video? it became commonplace for PC games to use the storage capacity ...
18
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2answers
4k views

How did the Sega CD decompress video?

In the early nineties, Sega released the Sega CD, a.k.a. Mega CD, an add-on that attached a CD-ROM drive to the Mega Drive a.k.a. Genesis. Its primary or at least most conspicuous use was for full-...
5
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1answer
224 views

Can't install El-Fish on MS-DOS 6.22

El-Fish is a fish tank "game", where you have virtual fish on your screen. The game has no goal, it's more like an interactive screen saver. I got my version from a number of different sources, one ...
24
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5answers
5k views

How well known and how commonly used was Huffman coding in 1979?

Infocom's Z-Machine, designed in 1979, compresses text using a basic 5 bit code which is not very efficient in practice, achieving maybe a 1.5:1 compression ratio. Huffman coding would be far more ...
17
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2answers
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What is the difference between DriveSpace and DoubleSpace?

DriveSpace is the successor to DoubleSpace. Both are DOS systems that mount a Compressed Volume File as a drive, allowing ordinary programs to interface with a compressed drive without an intermediate ...
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1answer
746 views

What is the history of data compression tools on personal computers?

On UNIX, the progression of the most widespread data compression programs was as follows: (AFAIR: Pre System V) compact (suffix .C), dynamic Huffman coding (AFAIR: introduced in System V) pack (...
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4answers
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Why does MP3 audio decoding overwhelm retro CPU's?

Many retrocomputers from the late 80s and early 90s had audio DAC hardware support. This includes the Amiga, Classic Macintosh, and PC's with SoundBlaster add-on cards. Despite the fact that the MP3 ...
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2answers
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How to convert Amiga DMS to ADF?

Our demoscene group managed to release only one demo before it fell apart, but these being the early days of the Internet in my country, and me getting lucky with obtaining access to it and creating ...