ClearBuffer:
    xor a
FillBuffer:
    push de
    push bc
        ld d,a
        ld e,a
        call SafeInterruptDI
        push af
        ld (saveSP),sp
        ld sp,LCDBuffer+768
        ld b,32
_           push de
            push de
            push de
            push de
            push de
            push de
            push de
            push de
            push de
            push de
            push de
            push de
            djnz -_
        ld sp,(saveSP)
    pop af
    pop bc
    pop de
        ret c
    ei
    ret
SafeInterruptDI:
    xor a       ;Set nc (interrupts)
    out ($20),a     ;Set speed to slow
    push    af      ;Check interrupts
    pop af
    ld  a,i     ;pe if interrupt
    di
        ret pe      ;Return if interrupts on
    dec sp      ;Otherwise, robust test
    dec sp
    pop af
    or  a       ;Set nc (interrupts)
        ret nz      ;Return if interrupts on
    scf         ;Set c (no interrupts)
    ret         ;Return
; safely returns interrupt
; inputs    af = state flags
SafeInterruptEI:
    ret c
    ei
    ret