Hacker News Reader

Comment by toolslive | Hacker News Reader

80s C64 demos already used compression (both Lempel-Ziv style and Huffman). Suppose the demo had 3 parts. When part 1 was running, part 2 and 3 were present in memory in compressed form (both code and data). When it was time to run part 2, it would be decompressed over the code and data of part 1. etc

View on HN

Compressing cracked games was a big thing too. There would be a lot of competition to get the smallest version of a game for faster downloading from a BBS, getting more games on a floppy disk etc. Getting the best compression software was a sign that you were an ‘elite’ cracker. (Disclaimer - was part of that scene as a young teen)

Wow, that is innovative. Something like overlays in certain versions of Turbo Pascal, but better.

Never used Turbo Pascal overlays but we had a product on OS/2 using a Realia compiler that when ported to DOS didn't fit. The overlays destroyed performance. I ended up making a segmented that spilt the call graph into mostly subtree by selecting the subroots. A small set of the shared pets got to live in non overlay memory. There was still a little thrashing because the splits weren't exclusive or of similar sizes but it worked remarkably well.

>The overlays destroyed performance.

True. A space-time tradeoff.

>I ended up making a segmented that spilt the call graph into mostly subtree by selecting the subroots. A small set of the shared pets got to live in non overlay memory.

I didn't get what you mean by "making a segmented" and "shared pets". Typos?

Reply on news.ycombinator.com