hello.z80

#define     progStart   $0000
#define     z80_ram_start   $0400
#define     z80_ram_size    $0004

.org        progStart
    LD  DE, (ram_size)
    LD  IX, (ram_start)

    LD  A, $01
loop1:
    LD (IX+0), A
    CP (IX+0)
    JP NZ, err

    INC IX
    DEC DE

    JP NZ, loop1

fine:
    NOP
    JP fine

err:
    halt

ram_size:
    .dw z80_ram_size

ram_start:
    .dw z80_ram_start

ram_de:
    .dw $0000