Coding Tricks Used in the C64 Game Seawolves (2025) (kodiak64.co.uk)
110 points by atan2 10 hours ago
Luc 9 hours ago
> However, you can save 1 byte of RAM by using the branch instructions instead, as long as you know which flag(s), if any, are guaranteed to be on or off at the jump point.
> For example, if you know the carry flag will always be clear at the jump point, and if the jump distance is within branching range, you can replace JMP with BCC.
However if the BCC crosses a page boundary it'll take 4 cycles, one cycle longer than a JMP.
solarisos 4 hours ago
There is something incredibly refreshing about looking at C64 optimizations. Today we throw gigabytes of RAM at simple CRUD apps, while these developers were counting every single cycle and byte. It’s a good reminder that 'efficiency' used to be a core requirement, not an afterthought.
stronglikedan an hour ago
There was no such thing as premature optimization back then.
solarisos 34 minutes ago
Exactly. When your total memory is 64KB, all optimization is mature optimization.
It's a fascinating contrast to the modern 'move fast and break things' approach. Back then, if your routine was 3 cycles too slow, the sprite didn't just 'lag'—the entire raster effect collapsed. There was a level of deterministic discipline that we've largely abstracted away in favor of developer velocity.
publicdebates 3 hours ago
And starting fires or making coats used to be forms of art, now we just buy a Zippo and a London Fog and call it an afternoon. Jobs evolve to specialize. I call that progress.
kleiba 3 hours ago
And yet there's a difference between a cheaply made coat from an Asian sweat shop and one made with quality materials by a skilled tailor.
solarisos 2 hours ago
publicdebates an hour ago
dorianmariecom 9 hours ago
diydsp 9 hours ago
Ah so with splites you can have a 24 pix wide column of arbitrary data that can be slid around left to right....and may act as an "echo" of the players movement like in this game...or possibly even different physics...
I love the stacking of boolean ops before branches, too.
empressplay 6 hours ago
Interesting stuff! Regarding game sales, other developers have had more success putting their games on physical media (particularly cartridges).