Something that came up on IRC today, the TAStudio state sizes for C64 games seem unusually large for a machine which has 64kB RAM.
I tested a few roms, they seem to use either 0.26MB, 1.04MB or 4.26MB:
0.26MB
Action Biker (1985)(Mastertronic).tap [841kB]
Attack of the Mutant Camels (1983)(Llamasoft).crt [8.07kB]
Attack of the Mutant Camels (1983)(Llamasoft).tap [145kB]
Batman - The Movie (1989)(Ocean Software).crt [129kB]
Batman - The Movie (1989)(Ocean Software)(Side A).tap [1.55MB]
Choplifter (1982)(Broderbund).crt [16.0kB]
Close Encounters (1994)(Mr. Computer).crt [8.07kB]
Decathlon (1983)(Activision).crt [16.0kB]
Double Dragon (1989)(Melbourne House).crt [128kB]
Double Dragon (1989)(Melbourne House).tap [1.33MB]
Shadow of the Beast (1990)(Ocean Software).crt [256kB]
Spy Hunter (1983)(U.S. Gold).crt [16.0kB]
Spy Hunter (1983)(U.S. Gold).tap [246kB]
Toki (1991)(Ocean Software).crt [128kB]
Wonderboy (1987)(Activision).crt [64.1kB]
1.04MB
Attack of the Mutant Camels (1983)(Llamasoft).d64 [170kB]
* Attack of the Mutant Camels (1983)(Llamasoft).t64 [7.41kB]
Double Dragon 1 (1989)(Melbourne House).d64 [170kB]
Ghostbusters.crt [33kB]
Leaderboard Golf (1986)(Access Software).crt [33kB]
Space Taxi (1984)(Muse Software).d64 [170kB]
Spy Hunter (1983)(U.S. Gold).d64 [170kB]
4.26MB
Cabal_(NOS)_(Ocean_1989).crt [208kB]
Jumpman_-_Space_Taxi.crt [658kB]
From that relatively small sample size, seems like any floppy disk image will use 1.04MB, any (raw) tape image will use 0.26MB and most cartridges will use 0.26MB, but some use 1.04MB, few even 4.26MB. Any idea why or how?
* There're two tape
formats for C64, .tap (which is a raw tape file, shows up as a supported format in BizHawk's Open ROM dialog) and .t64 (which was originally designed for C64s, doesn't show up as supported but still works, it just loads as a floppy image)
From the cartridge ROMs I tested, one didn't seem to work, it just booted into normal C64 startup. Tested on fresh Vice, worked fine: "Leaderboard Golf (1986)(Access Software).crt"