; Input:
;  b = col
;  c = row
; Ouput:
;  cf set if clipped
;  a = mask
;  hl = address
    ld  a,b
    add a,$100-96
    ret c
    sla c
    ret c
    sla c
    ret c
    ld  e,b
    ld  b,0
    ld  hl,(Buffer)
    add hl,bc
    add hl,bc
    add hl,bc
    ld  d,b
    srl e
    srl e
    srl e
    add hl,de
    and $07
    ld  b,a
    ld  a,$80
    ret z
    rrca
    djnz    $-1
    ret