ld hl,RamArea ;a label for an arbitrary section of RAM
ld a,(foo)    ;load the value of some memory location. "foo" is the label of a 16-bit address.
ld b,a        ;use this as a loop counter.
xor a         ;set A to zero

loop:         ;creates a list of ascending values starting at zero. Each is stored at a different memory location
ld (hl),a     ;store A in ram
inc a         ;ensures each value is different.
inc hl        ;next element of list
djnz loop