davidblackuk

; IN  -   B = pixel row (0..191)
; IN  -   C = character column (0..31)
; OUT -  HL = screen address
; OUT -  DE = trash
coords_to_address:  
    ld  h, 0
    ld  l, b            ; hl = row
    add hl, hl          ; hl = row number * 2
    ld  de, screen_map  ; de = screen map
    add hl, de          ; de = screen_map + (row * 2)