! � Decimal number output from
 � 6502 assembly language
 � by Pete Dawes
( � (c) The Micro User
2 � September 1990
< � 7:hex=&80:work=&82
F decimal=&84:oswrch=&FFEE
P � pass=0 � 2 � 2
Z P%=&C00:[OPT pass
d .reset
n LDA #0
x  STA decimal+0:STA decimal+1
�  STA decimal+2:STA decimal+3
�  STA decimal+4:STA decimal+5
�
 .convert
� LDA #0
� STA work:STA work+1
� CLC:LDX #16
�
 .loop
� ROL hex:ROL hex+1
� ROL work:ROL work+1
� SEC:LDA work
� SBC #10:TAY
� LDA work+1
� SBC #0:BCC less

 STY work:STA work+1


 .less

 DEX:BNE loop

" ROL hex:ROL hex+1

, CLC:LDA work

6 ADC #48

@ JSR concatenate

J LDA hex:�A hex+1

T BNE convert

^ LDX decimal

h LDY #1

r .print

| LDA decimal,Y

� JSR oswrch

� INY:DEX

� BNE print

� RTS

� .concatenate

� PHA:LDY decimal

�
 BEQ zero

�
 .move

� LDA decimal,Y

� STA decimal+1,Y

� DEY:BNE move

�
 .zero

� PLA
 STA decimal+1
 INC decimal
 RTS
&
 ]:� pass
0 � Demonstration routine
: !hex=&FFFF:�do
D !hex=&8000:�do
N !hex=&0:�do
X !hex=&E31D:�do
b !hex=&730:�do
l !hex=&C00:�do
v �
�
 � �do
�< � �7)"Hexadecimal = &";�~!hex:�"Decimal equivalent = ";
� � &C00
� �:�
� �
�

00000000  0d 00 0a 21 20 f4 20 44  65 63 69 6d 61 6c 20 6e  |...! . Decimal n|
00000010  75 6d 62 65 72 20 6f 75  74 70 75 74 20 66 72 6f  |umber output fro|
00000020  6d 0d 00 14 1d 20 f4 20  36 35 30 32 20 61 73 73  |m.... . 6502 ass|
00000030  65 6d 62 6c 79 20 6c 61  6e 67 75 61 67 65 0d 00  |embly language..|
00000040  1e 14 20 f4 20 62 79 20  50 65 74 65 20 44 61 77  |.. . by Pete Daw|
00000050  65 73 0d 00 28 19 20 f4  20 28 63 29 20 54 68 65  |es..(. . (c) The|
00000060  20 4d 69 63 72 6f 20 55  73 65 72 0d 00 32 15 20  | Micro User..2. |
00000070  f4 20 53 65 70 74 65 6d  62 65 72 20 31 39 39 30  |. September 1990|
00000080  0d 00 3c 19 20 eb 20 37  3a 68 65 78 3d 26 38 30  |..<. . 7:hex=&80|
00000090  3a 77 6f 72 6b 3d 26 38  32 0d 00 46 1d 20 64 65  |:work=&82..F. de|
000000a0  63 69 6d 61 6c 3d 26 38  34 3a 6f 73 77 72 63 68  |cimal=&84:oswrch|
000000b0  3d 26 46 46 45 45 0d 00  50 15 20 e3 20 70 61 73  |=&FFEE..P. . pas|
000000c0  73 3d 30 20 b8 20 32 20  88 20 32 0d 00 5a 16 20  |s=0 . 2 . 2..Z. |
000000d0  50 25 3d 26 43 30 30 3a  5b 4f 50 54 20 70 61 73  |P%=&C00:[OPT pas|
000000e0  73 0d 00 64 0b 20 2e 72  65 73 65 74 0d 00 6e 0b  |s..d. .reset..n.|
000000f0  20 4c 44 41 20 23 30 0d  00 78 20 20 53 54 41 20  | LDA #0..x  STA |
00000100  64 65 63 69 6d 61 6c 2b  30 3a 53 54 41 20 64 65  |decimal+0:STA de|
00000110  63 69 6d 61 6c 2b 31 0d  00 82 20 20 53 54 41 20  |cimal+1...  STA |
00000120  64 65 63 69 6d 61 6c 2b  32 3a 53 54 41 20 64 65  |decimal+2:STA de|
00000130  63 69 6d 61 6c 2b 33 0d  00 8c 20 20 53 54 41 20  |cimal+3...  STA |
00000140  64 65 63 69 6d 61 6c 2b  34 3a 53 54 41 20 64 65  |decimal+4:STA de|
00000150  63 69 6d 61 6c 2b 35 0d  00 96 0d 20 2e 63 6f 6e  |cimal+5.... .con|
00000160  76 65 72 74 0d 00 a0 0b  20 4c 44 41 20 23 30 0d  |vert.... LDA #0.|
00000170  00 aa 18 20 53 54 41 20  77 6f 72 6b 3a 53 54 41  |... STA work:STA|
00000180  20 77 6f 72 6b 2b 31 0d  00 b4 10 20 43 4c 43 3a  | work+1.... CLC:|
00000190  4c 44 58 20 23 31 36 0d  00 be 0a 20 2e 6c 6f 6f  |LDX #16.... .loo|
000001a0  70 0d 00 c8 16 20 52 4f  4c 20 68 65 78 3a 52 4f  |p.... ROL hex:RO|
000001b0  4c 20 68 65 78 2b 31 0d  00 d2 18 20 52 4f 4c 20  |L hex+1.... ROL |
000001c0  77 6f 72 6b 3a 52 4f 4c  20 77 6f 72 6b 2b 31 0d  |work:ROL work+1.|
000001d0  00 dc 11 20 53 45 43 3a  4c 44 41 20 77 6f 72 6b  |... SEC:LDA work|
000001e0  0d 00 e6 10 20 53 42 43  20 23 31 30 3a 54 41 59  |.... SBC #10:TAY|
000001f0  0d 00 f0 0f 20 4c 44 41  20 77 6f 72 6b 2b 31 0d  |.... LDA work+1.|
00000200  00 fa 14 20 53 42 43 20  23 30 3a 42 43 43 20 6c  |... SBC #0:BCC l|
00000210  65 73 73 0d 01 04 18 20  53 54 59 20 77 6f 72 6b  |ess.... STY work|
00000220  3a 53 54 41 20 77 6f 72  6b 2b 31 0d 01 0e 0a 20  |:STA work+1.... |
00000230  2e 6c 65 73 73 0d 01 18  11 20 44 45 58 3a 42 4e  |.less.... DEX:BN|
00000240  45 20 6c 6f 6f 70 0d 01  22 16 20 52 4f 4c 20 68  |E loop..". ROL h|
00000250  65 78 3a 52 4f 4c 20 68  65 78 2b 31 0d 01 2c 11  |ex:ROL hex+1..,.|
00000260  20 43 4c 43 3a 4c 44 41  20 77 6f 72 6b 0d 01 36  | CLC:LDA work..6|
00000270  0c 20 41 44 43 20 23 34  38 0d 01 40 14 20 4a 53  |. ADC #48..@. JS|
00000280  52 20 63 6f 6e 63 61 74  65 6e 61 74 65 0d 01 4a  |R concatenate..J|
00000290  15 20 4c 44 41 20 68 65  78 3a 84 41 20 68 65 78  |. LDA hex:.A hex|
000002a0  2b 31 0d 01 54 10 20 42  4e 45 20 63 6f 6e 76 65  |+1..T. BNE conve|
000002b0  72 74 0d 01 5e 10 20 4c  44 58 20 64 65 63 69 6d  |rt..^. LDX decim|
000002c0  61 6c 0d 01 68 0b 20 4c  44 59 20 23 31 0d 01 72  |al..h. LDY #1..r|
000002d0  0b 20 2e 70 72 69 6e 74  0d 01 7c 12 20 4c 44 41  |. .print..|. LDA|
000002e0  20 64 65 63 69 6d 61 6c  2c 59 0d 01 86 0f 20 4a  | decimal,Y.... J|
000002f0  53 52 20 6f 73 77 72 63  68 0d 01 90 0c 20 49 4e  |SR oswrch.... IN|
00000300  59 3a 44 45 58 0d 01 9a  0e 20 42 4e 45 20 70 72  |Y:DEX.... BNE pr|
00000310  69 6e 74 0d 01 a4 08 20  52 54 53 0d 01 ae 11 20  |int.... RTS.... |
00000320  2e 63 6f 6e 63 61 74 65  6e 61 74 65 0d 01 b8 14  |.concatenate....|
00000330  20 50 48 41 3a 4c 44 59  20 64 65 63 69 6d 61 6c  | PHA:LDY decimal|
00000340  0d 01 c2 0d 20 42 45 51  20 7a 65 72 6f 0d 01 cc  |.... BEQ zero...|
00000350  0a 20 2e 6d 6f 76 65 0d  01 d6 12 20 4c 44 41 20  |. .move.... LDA |
00000360  64 65 63 69 6d 61 6c 2c  59 0d 01 e0 14 20 53 54  |decimal,Y.... ST|
00000370  41 20 64 65 63 69 6d 61  6c 2b 31 2c 59 0d 01 ea  |A decimal+1,Y...|
00000380  11 20 44 45 59 3a 42 4e  45 20 6d 6f 76 65 0d 01  |. DEY:BNE move..|
00000390  f4 0a 20 2e 7a 65 72 6f  0d 01 fe 08 20 50 4c 41  |.. .zero.... PLA|
000003a0  0d 02 08 12 20 53 54 41  20 64 65 63 69 6d 61 6c  |.... STA decimal|
000003b0  2b 31 0d 02 12 10 20 49  4e 43 20 64 65 63 69 6d  |+1.... INC decim|
000003c0  61 6c 0d 02 1c 08 20 52  54 53 0d 02 26 0d 20 5d  |al.... RTS..&. ]|
000003d0  3a ed 20 70 61 73 73 0d  02 30 1c 20 f4 20 44 65  |:. pass..0. . De|
000003e0  6d 6f 6e 73 74 72 61 74  69 6f 6e 20 72 6f 75 74  |monstration rout|
000003f0  69 6e 65 0d 02 3a 13 20  21 68 65 78 3d 26 46 46  |ine..:. !hex=&FF|
00000400  46 46 3a f2 64 6f 0d 02  44 13 20 21 68 65 78 3d  |FF:.do..D. !hex=|
00000410  26 38 30 30 30 3a f2 64  6f 0d 02 4e 10 20 21 68  |&8000:.do..N. !h|
00000420  65 78 3d 26 30 3a f2 64  6f 0d 02 58 13 20 21 68  |ex=&0:.do..X. !h|
00000430  65 78 3d 26 45 33 31 44  3a f2 64 6f 0d 02 62 12  |ex=&E31D:.do..b.|
00000440  20 21 68 65 78 3d 26 37  33 30 3a f2 64 6f 0d 02  | !hex=&730:.do..|
00000450  6c 12 20 21 68 65 78 3d  26 43 30 30 3a f2 64 6f  |l. !hex=&C00:.do|
00000460  0d 02 76 06 20 e0 0d 02  80 0a 20 dd 20 f2 64 6f  |..v. ..... . .do|
00000470  0d 02 8a 3c 20 f1 20 8a  37 29 22 48 65 78 61 64  |...< . .7)"Hexad|
00000480  65 63 69 6d 61 6c 20 3d  20 26 22 3b c3 7e 21 68  |ecimal = &";.~!h|
00000490  65 78 3a f1 22 44 65 63  69 6d 61 6c 20 65 71 75  |ex:."Decimal equ|
000004a0  69 76 61 6c 65 6e 74 20  3d 20 22 3b 0d 02 9e 0b  |ivalent = ";....|
000004b0  20 d6 20 26 43 30 30 0d  02 a8 08 20 f1 3a f1 0d  | . &C00.... .:..|
000004c0  02 b2 06 20 e1 0d ff                              |... ...|
000004c7