exx test

    module spr8
    //  first regs hldebc
    ld hl,sprite
    ld de,scrAddr
    //  bc - free
    exx
    //  second regs hldebc
    ld hl,mask
    ld de,scrAddr
    ld b,8
nextSymbol:
    //  push de     11t
    ld c,8
nextLine:
    ld a,(de)   //  screen
    and (hl)    //  mask
    inc hl
    exx
    //  first regs hldebc
    or (hl)     //  sprite
    inc hl
    exx
    //  second regs hldebc
    ld (de),a   //  screen
    inc d       //  call to screen line, for calculate can using [de,bc] from first regs hldebc
    dec c
    jr nz,nextLine
    //  pop de      10t
    //  inc e       4t
    //      = 25t
    //------
    exx
    //  first regs hldebc
    ld a,d
    exx
    //  second regs hldebc
    ld d,a
    inc e
    //------ 20t vs 25t at push de,pop de,inc e
    // of course can use: |ld a,d|sub 8|ld d,a|inc e| = 19t without stack or exx
    dec b
    jr nz,nextSymbol
    ret

    endmodule