DCPU-16 Assembler

Input

; (Notch's example)

; Try some basic stuff
              SET A, 0x30              ; 7c01 0030
              SET [0x1000], 0x20       ; 7de1 1000 0020
              SUB A, [0x1000]          ; 7803 1000
              IFN A, 0x10              ; c00d 
              SET PC, crash            ; 7dc1 001a [*]
              
; Do a loopy thing
              SET I, 10                ; a861
              SET A, 0x2000            ; 7c01 2000
:loop         SET [0x2000+I], [A]      ; 2161 2000
              SUB I, 1                 ; 8463
              IFN I, 0                 ; 806d
              SET PC, loop             ; 7dc1 000d [*]

; Call a subroutine
              SET X, 0x4               ; 9031
              JSR testsub              ; 7c10 0018 [*]
              SET PC, crash            ; 7dc1 001a [*]

:testsub      SHL X, 4                 ; 9037
              SET PC, POP              ; 61c1
                
; Hang forever. X should now be 0x40 if everything went right.
:crash        SET PC, crash            ; 7dc1 001a [*]

; [*]: Note that these can be one word shorter and one cycle faster by using the short form (0x00-0x1f) of literals,
;      but my assembler doesn't support short form labels yet.