0001                         ; sample program for 6809 assembler
0002                         ;
0003                         ; program to add two multiple precision operands
0004                         ;
0005                         
0006 0008                    nbytes  EQU     8
0007                         
0008 1000                            ORG     $1000      ; start at 1000H
0009                         
0010                         ; BCD addition subroutine
0011                         
0012 1000 c6 08              bcd     ldb     #nbytes
0013 1002 be 01 00                   ldx     addr       ; load data address
0014 1005 1c fe                      andcc   #$0FE      ; clear carry bit
0015 1007 a6 07              next    lda     nbytes-1,x ; start loop
0016 1009 a9 0e                      adca    nbytes-1*2,x
0017 100b 19                         daa
0018 100c a7 88 15                   sta     nbytes-1*3,x
0019 100f 30 1f                      leax    -1,x
0020 1011 5a                         decb
0021 1012 26 f3                      bne     next
0022 1014 39                         rts                ; end of subroutine
0023                         
0024                         ; begin main program
0025                         ; (uses subroutine 'bcd')
0026 1100                            ORG     $1100      ; main program at 1100H
0027 1100 10 ce 01 3f                lds     #$013f     ; initialise SP
0028 1104 be 01 02                   ldx     temp
0029 1107 bf 01 00                   stx     addr
0030 110a bd 10 00                   jsr     bcd
0031 110d 8e 01 0a                   ldx     #msg       ; get address of string
0032 1110 bd 11 16                   jsr     print      ; and print it
0033 1113 12                         nop
0034 1114 20 fe              loop    bra     loop       ; loop forever
0035                         
0036                         ; dummy routine print
0037 1116 39                 print   rts
0038                         
0039                         ; allocate data area
0040 0100                            ORG     $0100
0041 0100 00 00              addr    FDB     0
0042 0102                    temp    RMB     nbytes
0043 010a 6d 75 6c 74 69 70  msg     FCC     "multiplication done"
     6c 69 63 61 74 69
     6f 6e 20 64 6f 6e
     65
0044 011d 0d 00                      FCB     $0D,00
0045                                 END




Motorola S records (for downloading to microprocessor system)
S1181000C608BE01001CFEA607A90E19A78815301F5A26F33974
S11A110010CE013FBE0102BF0100BD10008E010ABD11161220FE3982
S10501000000F9
S118010A6D756C7469706C69636174696F6E20646F6E650D001B
S9030000FC