It's just a big screen

8-bit game programmers know how to do today’s #adventofcode2023 conceptually. We spent our youth boundary-checking stuff on a screen represented in contiguous memory. The only “problem” is that the data is 19600 bytes. On the PET I used 0x3000-0x7c90 as my “screen.” Looking for stuff on a 140x140 grid is similar to doing it on a 40x25 grid; it’s just 19x larger. I already had several assembly routines in my toolbox for this one. I could speed this up, but it works. On to trying it in Elixir…