XDEF FINDCHAR_TEST       
            ABSENTRY FINDCHAR_TEST   
            ORG $3800
NR_OCCURRENCES:
            DS.W 1            
            ORG $4000
MEMSTART:   DC.B "This is a test to count the occurrences of the lower case letter e"
MEMEND:     DC.B 0            
FINDCHAR_TEST:
            LDS #$3F00
            LDX #MEMSTART
            PSHX
            LDX #MEMEND
            PSHX
            LDAA #'e'
            PSHA
            LDX #NR_OCCURRENCES
            PSHX
            BSR FINDCHAR
            LEAS 7,SP
STOP_HERE   BRA STOP_HERE
            
FINDCHAR:   PSHD
            PSHX
            PSHY
            LDX 13,SP
            LDY #0
            LDAA 10,SP
NOT_DONE:   CMPA 1,X+
            BNE NOT_FOUND
            INY
NOT_FOUND:
            CPX  11,SP
            BNE NOT_DONE
            STY [8,SP]
            PULY
            PULX
            PULD
            RTS

            ORG $FFFE
            DC.W FINDCHAR_TEST