April 9th, 2009

apple

I wish I knew earlier

From Assembly Language for the Applesoft Programmer by C. W. Finley, Jr. and Roy E. Myers:


If an indirect jump does lie across a page boundary, a jump is performed and the results are predictable. See if you can figure it out. This is rumored to be a "technique" used by "master" game programmers to "disguise" their code.


I find the heavy use of scare quotes charming, and I suspect I know what the predictable behavior alluded to here is.

I find it particularly interesting to stretch my brain to try to imagine a time when disassembling machine code was a thing that people had to guard against.