I tried to implement FizzBuzz in DCPU-16. I use this web emulator: http://mappum.github.com/DCPU-16/ (repository: https://github.com/mappum/DCPU-16).
It stops before the end of the loop. Why?
How can I optimize it? I'm a high level language programmer who don't know anything about asm. Have you some basic resource on this?
More infos on DCPU-16: official specs: http://0x10c.com/doc/dcpu-16.txt - unofficial specs: http://0x10.cc/
The code:
; FizzBuzz in DCPU-16
SET Z, 0x8000
SET I, 1
:loop
JSR print
ADD I, 1
IFN I, 100
SET PC, loop
BRK
:print
ADD Z, 1
SET [Z], 10
SET A, I
MOD A, 3
IFE A, 0
JSR printFizz
SET B, I
MOD B, 5
IFE B, 0
JSR printBuzz
SET C, A
IFG B, A
SET C, B
ADD A, B
IFG A, C
JSR printNumber
SET PC, POP
:printNumber
SET A, I
IFG I, 9
DIV A, 10
JSR printDigit
IFG 10, I
SET PC, POP
SET A, I
MOD A, 10
JSR printDigit
SET PC, POP
:printDigit
ADD A, 48
ADD Z, 1
SET [Z], A
SET PC, POP
:printFizz
ADD Z, 1
SET [Z], 70
ADD Z, 1
SET [Z], 105
ADD Z, 1
SET [Z], 122
ADD Z, 1
SET [Z], 122
SET PC, POP
:printBuzz
ADD Z, 1
SET [Z], 66
ADD Z, 1
SET [Z], 117
ADD Z, 1
SET [Z], 122
ADD Z, 1
SET [Z], 122
SET PC, POP
The console space on that emulator is only 0x8000 - 0x8180.
Looks like you're hitting the end of the console, so your output cuts off mid-letter and you end up writing to unrelated memory.
If you look in the debugger: the register I is 0x64 at compeletion, which is 100 in base-10 (so your loop finished).