FizzBuzz/Assembly: Difference between revisions

=={{header|Z80 Assembly}}==

For the Amstrad CPC (should work with e.g. the built-in assembler in JavaCPC; use <tt>call &4000</tt> to start from BASIC):

<lang z80>org &4000 ; put code at memory address 0x4000

wr_char equ &bb5a ; write ASCII character in register A to screen

cursor equ &bb78 ; get cursor position

push bc

push de

push hl

ld b,100 ; loop from 100 to 1

loop:

; check for Fizz condition

ld a,(count3)

dec a

jr nz,next3

push bc

ld b,4

ld de,fizz

printfizz:

ld a,(de)

call wr_char

inc de

djnz printfizz

pop bc

ld a,3

next3:

ld (count3),a

; check for Buzz condition

ld a,(count5)

dec a

jr nz,next5

push bc

ld b,4

ld de,buzz

printbuzz:

ld a,(de)

call wr_char

inc de

djnz printbuzz

pop bc

ld a,5

next5:

ld (count5),a

; test if cursor is still in first column

; (i.e., no Fizz or Buzz has been printed)

call cursor

ld a,h

dec a

jr nz,skipnum

; print number

push bc

ld b,3

ld de,count

loop2:

ld a,(de)

call wr_char

inc de

djnz loop2

pop bc

skipnum:

; print carriage return/line feed

ld a,13

call wr_char

ld a,10

call wr_char

; increment rightmost digit

ld hl,count+2

inc (hl)

ld a,(hl)

; check if value is 10 (ASCII 58)

; if so, set to 48 (ASCII 0) and increase 10's digit

cp 58

jr nz,noinc

ld a,48

ld (count+2),a

ld (hl),a

dec hl

inc (hl)

ld a,(hl)

; check second-to-right digit, if it is 10 (0), carry over to 100's

cp 58

jr nz,noinc

ld a,48

ld (count+1),a

ld (hl),a

dec hl

inc (hl)

noinc:

djnz loop

pop hl

pop de

pop bc

; return to BASIC

ret

count:

db "001"

count3:

db 3

count5:

db 5

fizz:

db "Fizz"

buzz:

db "Buzz"</lang>