; SAVE#D3:TETWRIT.M65
      .OPT NO EJECT
;     .OPT NO LIST
;
      *=  $9BFF-$66
SOR   =   $F0
DES   =   $F2
END   =   $F4
EEND  =   $F6
;
START LDY #$00
L1  LDA (SOR),Y
    STA DES,Y
    INY 
    CPY #$04
    BNE L1
L2  JSR INCS
    DEY 
    BNE L2
L3  LDA (SOR),Y
    STA (DES),Y
    JSR CMPDESEND
    JSR INCS
    JSR INCD
    JMP L3
;
INCS INC SOR
    BNE L4
    INC SOR+1
L4  RTS 
;
INCD INC DES
    BNE L5
    INC DES+1
L5  RTS 
;
CMPDESEND LDA DES
    CMP EEND
    BCC L6
    LDA DES+1
    CMP EEND+1
    BCC L6
    PLA 
    PLA 
    RTS 
L6  LDA DES
    CMP END
    BCC L7
    LDA DES+1
    CMP END+1
    BCC L7
    PLA 
    PLA 
    JSR INCS
    JMP START
L7  RTS 
L8  SEI 
    LDA #0
    STA $D40E
    JSR START
    LDA #$C0
    STA $D40E
    CLI 
    JMP L8
    .BYTE $00