6502 machine code (C64), 51 53 bytes (Cracked, proper edit later)

6502 machine code (C64), 51 53 bytes (Cracked)

Input is 52768 and 23 (SYS49152,52768,23)

The second parameter is directly written to D018, a control register of the VIC-II graphics chip. Using a suitable reference, you can deduce what to write there for setting lowercase mode without changing other modes and the address of the screen memory: $17, or decimal 23. With that, you can follow the arithmetics in the code, so the first parameter ends up with the correct string address in $14/$15 (little-endian). A more in-depth explanation can be found in the crack.

6502 machine code (C64), 51 53 bytes

6502 machine code (C64), 51 53 bytes (Cracked, proper edit later)

Fixed error: It said 33 bytes first, my bad, that was a hexadecimal number. The code didn't change, I just fixed the byte count!

Update: Added two bytes for the load address to make this an executable C64 PRG file in response to the discussion on meta

Update: Added two bytes for the load address to make this an executable C64 PRG file in response to the discussion on meta