PROG START
     LAD   GR0,0
     LAD   GR2,0
NEX  ADDA  GR2,A
     LAD   GR0,1,GR0
     CPA   GR0,B
     JNZ   NEX
     LAD   GR1,GR2
     CALL
     OUT   BUF,LEN
     RET
     END
BD   START
     LAD   GE3,BUF
     LAD   GR3,4,GR3
BD1  LAD   GR2,0
BD2  CPL   GR1,BD10
     JMI   BD3
     SUBA  GR1,BD10
     LAD   GR2,1,1GR2
     JUMP  BD2
BD3  OR    GR1,BD0
     ST    GR1,0,GR3