NAM GRAY/BIN
       OPT O
       ORG $100
       SPC 2
******************************************
*          GRAY CODE TO BINARY CONVERSION     *
*         16 BIT ACCURACY - REENTRANT CODE    *
******************************************
       SPC 2
GRYBIN PSHA
       PSHB
       LDAA #$0F
       PSHA
       TSX
       LDAA 2,X
G2     LSRA
       RORB
       EORA 2,X
       EORB 1,X
       DEC 0,X
        BNE G2
       INS
       INS
       INS
       RTS
       SPC 2
       END