�> SWTEXT
� mcode &200
xcoord=&70
(ycoord=&71
2fire=&72
<savereg=&FC
F'start=&350 :�: screen start address
P&screen=&355 :�: screen mode OS 1.2
Zsheila=&FE00
d5drb=&FE40 :�: system 6522 input/output register B
n5ifr=&FE4D :�: system 6522 interrupt flag register
x7ier=&FE4E :�: system 6522 interrupt enable register
�� pass=4 � 6 � 2
�O%=mcode
�P%=&8000
�
[OPT pass
�BRK
�BRK
�BRK
�&JMP service \ service entry to ROM
�6EQUB &82 \ ROM type byte indicates a service entry
�3EQUB copyright � 256 \ copyright offset pointer
�.BRK  \ BRK serves as binary version number
�'EQUS"Light pen Text" \ title string
�.copyright

)BRK \ start of copyright/end of title

%EQUS "(C) Gordon Horsington 1987"

BRK \ copyright terminator

"	.exit

,PLA

6STA savereg

@2LDA #&05 \ unrecognised interrupt service call

J.return

TRTS

^.service

h1CMP #&05 \ is this an unrecognised interrupt?

r(BNE return \ branch if not interrupt

|:LDA savereg \ load interrupt accumulator save register

�"PHA \ and push it on the stack

�.LDA ifr \ load system VIA interrupt status

�"BPL exit \ exit if bit 7 clear

�� #&08 \ � with %00001000

�.BEQ exit \ exit if not light pen interrupt

�TXA

�PHA

�TYA

�PHA

�LDA drb \ clear interrupt

�PHA \ push data register B

�CLD \ clear decimal flag

�,LDY screen \ screen mode into Y register
.LDA start \ screen start address, low byte
STA ycoord
1LDA start+1 \ screen start address, high byte
&STA ycoord+1
0CPY #&07 \ is this mode 7?
:
BEQ mode7
DLSR ycoord+1
N"ROR ycoord \ start address � 2
XLSR ycoord+1
b"ROR ycoord \ start address � 4
lLSR ycoord+1
v"ROR ycoord \ start address � 8
�*JMP continue \ skip mode 7 calculation
�
.mode7
�!SEC \ prepare for subtraction
�LDA ycoord+1
�SBC #&54
�4STA ycoord+1 \ subtract &5400 from start address
�
.continue
�LDA offsetlow,Y
�CLC \ prepare for addition
�#ADC ycoord \ add trim to offset
�STA ycoord
�LDA #&00
�ADC ycoord+1
STA ycoord+1
5SEC \ prepare to subtract offset from lp register
+LDX #&11 \ light pen register, low byte
 &STX sheila \ 6845 address register
*%LDA sheila+1 \ 6845 data register
4*SBC ycoord \ subtract offset, low byte
>"STA ycoord \ low byte - offset
H0DEX \ X = &10, light pen register, high byte
R&STX sheila \ 6845 address register
\%LDA sheila+1 \ 6845 data register
f-SBC ycoord+1 \ subtract offset, high byte
p%STA ycoord+1 \ high byte - offset
z*LDA #&00 \ prepare for 16 bit division
�+STA xcoord \ clear low partial dividend
�	.next
�-ASL ycoord \ shift dividend/quotient left
�/ROL ycoord+1 \ shift dividend/quotient left
�1ROL xcoord \ shift bits into partial dividend
�&LDA xcoord \ load partial dividend
�!SEC \ prepare for subtraction
�"SBC width,Y \ subtract divisor
�+BCC done \ branch if dividend < divisor
�#INC ycoord \ increment quotient
�*STA xcoord \ save new partial dividend
�	.done
�DEX \ decrement bit counter
!BNE next \ branch for 16 bits
#LDA scale,Y \ screen mode scale
1BEQ pullout \ branch if modes 0, 3, 4, 6 or 7
$.TAX \ in mode1 and mode5 X=1, in mode2 X=2
.LDA xcoord
8.reduce
B#LSR A \ horizontal position � 2
LDEX
VBNE reduce
`STA xcoord
j.pullout
tPLA \ pull data register B
~� #&20 \ %00100000
�'STA fire \ store fire button status
�PLA
�TAY
�PLA
�TAX
�PLA
�STA savereg
�!LDA #&00 \ interrupt serviced
�$RTS \ return to operating system
�.offsetlow
�%EQUB &04 \ mode0, untrimmed = &06
�%EQUB &04 \ mode1, untrimmed = &06
%EQUB &04 \ mode2, untrimmed = &06

%EQUB &04 \ mode3, untrimmed = &06
%EQUB &03 \ mode4, untrimmed = &04
%EQUB &03 \ mode5, untrimmed = &04
(%EQUB &03 \ mode6, untrimmed = &04
2%EQUB &06 \ mode7, untrimmed = &08
<
.scale
FEQUD &00020100 \ modes 3-0
PEQUD &00000100 \ modes 7-4
Z
.width
dEQUD &50505050 \ modes 3-0
nEQUD &28282828 \ modes 7-4
x
.lastbyte
�]
��
�*OPT1,2
�M�("SAVE LPTEXT "+�~(mcode)+" + "+�~(lastbyte-&8000)+" FFFF8000 FFFF8000")
�*OPT0,0
�

00000000  0d 00 0a 0d f4 3e 20 53  57 54 45 58 54 0d 00 14  |.....> SWTEXT...|
00000010  10 de 20 6d 63 6f 64 65  20 26 32 30 30 0d 00 1e  |.. mcode &200...|
00000020  0e 78 63 6f 6f 72 64 3d  26 37 30 0d 00 28 0e 79  |.xcoord=&70..(.y|
00000030  63 6f 6f 72 64 3d 26 37  31 0d 00 32 0c 66 69 72  |coord=&71..2.fir|
00000040  65 3d 26 37 32 0d 00 3c  0f 73 61 76 65 72 65 67  |e=&72..<.savereg|
00000050  3d 26 46 43 0d 00 46 27  73 74 61 72 74 3d 26 33  |=&FC..F'start=&3|
00000060  35 30 20 3a f4 3a 20 73  63 72 65 65 6e 20 73 74  |50 :.: screen st|
00000070  61 72 74 20 61 64 64 72  65 73 73 0d 00 50 26 73  |art address..P&s|
00000080  63 72 65 65 6e 3d 26 33  35 35 20 3a f4 3a 20 73  |creen=&355 :.: s|
00000090  63 72 65 65 6e 20 6d 6f  64 65 20 4f 53 20 31 2e  |creen mode OS 1.|
000000a0  32 0d 00 5a 10 73 68 65  69 6c 61 3d 26 46 45 30  |2..Z.sheila=&FE0|
000000b0  30 0d 00 64 35 64 72 62  3d 26 46 45 34 30 20 3a  |0..d5drb=&FE40 :|
000000c0  f4 3a 20 73 79 73 74 65  6d 20 36 35 32 32 20 69  |.: system 6522 i|
000000d0  6e 70 75 74 2f 6f 75 74  70 75 74 20 72 65 67 69  |nput/output regi|
000000e0  73 74 65 72 20 42 0d 00  6e 35 69 66 72 3d 26 46  |ster B..n5ifr=&F|
000000f0  45 34 44 20 3a f4 3a 20  73 79 73 74 65 6d 20 36  |E4D :.: system 6|
00000100  35 32 32 20 69 6e 74 65  72 72 75 70 74 20 66 6c  |522 interrupt fl|
00000110  61 67 20 72 65 67 69 73  74 65 72 0d 00 78 37 69  |ag register..x7i|
00000120  65 72 3d 26 46 45 34 45  20 3a f4 3a 20 73 79 73  |er=&FE4E :.: sys|
00000130  74 65 6d 20 36 35 32 32  20 69 6e 74 65 72 72 75  |tem 6522 interru|
00000140  70 74 20 65 6e 61 62 6c  65 20 72 65 67 69 73 74  |pt enable regist|
00000150  65 72 0d 00 82 14 e3 20  70 61 73 73 3d 34 20 b8  |er..... pass=4 .|
00000160  20 36 20 88 20 32 0d 00  8c 0c 4f 25 3d 6d 63 6f  | 6 . 2....O%=mco|
00000170  64 65 0d 00 96 0c 50 25  3d 26 38 30 30 30 0d 00  |de....P%=&8000..|
00000180  a0 0d 5b 4f 50 54 20 70  61 73 73 0d 00 aa 07 42  |..[OPT pass....B|
00000190  52 4b 0d 00 b4 07 42 52  4b 0d 00 be 07 42 52 4b  |RK....BRK....BRK|
000001a0  0d 00 c8 26 4a 4d 50 20  73 65 72 76 69 63 65 20  |...&JMP service |
000001b0  5c 20 73 65 72 76 69 63  65 20 65 6e 74 72 79 20  |\ service entry |
000001c0  74 6f 20 52 4f 4d 0d 00  d2 36 45 51 55 42 20 26  |to ROM...6EQUB &|
000001d0  38 32 20 5c 20 52 4f 4d  20 74 79 70 65 20 62 79  |82 \ ROM type by|
000001e0  74 65 20 69 6e 64 69 63  61 74 65 73 20 61 20 73  |te indicates a s|
000001f0  65 72 76 69 63 65 20 65  6e 74 72 79 0d 00 dc 33  |ervice entry...3|
00000200  45 51 55 42 20 63 6f 70  79 72 69 67 68 74 20 83  |EQUB copyright .|
00000210  20 32 35 36 20 5c 20 63  6f 70 79 72 69 67 68 74  | 256 \ copyright|
00000220  20 6f 66 66 73 65 74 20  70 6f 69 6e 74 65 72 0d  | offset pointer.|
00000230  00 e6 2e 42 52 4b 20 20  5c 20 42 52 4b 20 73 65  |...BRK  \ BRK se|
00000240  72 76 65 73 20 61 73 20  62 69 6e 61 72 79 20 76  |rves as binary v|
00000250  65 72 73 69 6f 6e 20 6e  75 6d 62 65 72 0d 00 f0  |ersion number...|
00000260  27 45 51 55 53 22 4c 69  67 68 74 20 70 65 6e 20  |'EQUS"Light pen |
00000270  54 65 78 74 22 20 5c 20  74 69 74 6c 65 20 73 74  |Text" \ title st|
00000280  72 69 6e 67 0d 00 fa 0e  2e 63 6f 70 79 72 69 67  |ring.....copyrig|
00000290  68 74 0d 01 04 29 42 52  4b 20 5c 20 73 74 61 72  |ht...)BRK \ star|
000002a0  74 20 6f 66 20 63 6f 70  79 72 69 67 68 74 2f 65  |t of copyright/e|
000002b0  6e 64 20 6f 66 20 74 69  74 6c 65 0d 01 0e 25 45  |nd of title...%E|
000002c0  51 55 53 20 22 28 43 29  20 47 6f 72 64 6f 6e 20  |QUS "(C) Gordon |
000002d0  48 6f 72 73 69 6e 67 74  6f 6e 20 31 39 38 37 22  |Horsington 1987"|
000002e0  0d 01 18 1e 42 52 4b 20  5c 20 63 6f 70 79 72 69  |....BRK \ copyri|
000002f0  67 68 74 20 74 65 72 6d  69 6e 61 74 6f 72 0d 01  |ght terminator..|
00000300  22 09 2e 65 78 69 74 0d  01 2c 07 50 4c 41 0d 01  |"..exit..,.PLA..|
00000310  36 0f 53 54 41 20 73 61  76 65 72 65 67 0d 01 40  |6.STA savereg..@|
00000320  32 4c 44 41 20 23 26 30  35 20 5c 20 75 6e 72 65  |2LDA #&05 \ unre|
00000330  63 6f 67 6e 69 73 65 64  20 69 6e 74 65 72 72 75  |cognised interru|
00000340  70 74 20 73 65 72 76 69  63 65 20 63 61 6c 6c 0d  |pt service call.|
00000350  01 4a 0b 2e 72 65 74 75  72 6e 0d 01 54 07 52 54  |.J..return..T.RT|
00000360  53 0d 01 5e 0c 2e 73 65  72 76 69 63 65 0d 01 68  |S..^..service..h|
00000370  31 43 4d 50 20 23 26 30  35 20 5c 20 69 73 20 74  |1CMP #&05 \ is t|
00000380  68 69 73 20 61 6e 20 75  6e 72 65 63 6f 67 6e 69  |his an unrecogni|
00000390  73 65 64 20 69 6e 74 65  72 72 75 70 74 3f 0d 01  |sed interrupt?..|
000003a0  72 28 42 4e 45 20 72 65  74 75 72 6e 20 5c 20 62  |r(BNE return \ b|
000003b0  72 61 6e 63 68 20 69 66  20 6e 6f 74 20 69 6e 74  |ranch if not int|
000003c0  65 72 72 75 70 74 0d 01  7c 3a 4c 44 41 20 73 61  |errupt..|:LDA sa|
000003d0  76 65 72 65 67 20 5c 20  6c 6f 61 64 20 69 6e 74  |vereg \ load int|
000003e0  65 72 72 75 70 74 20 61  63 63 75 6d 75 6c 61 74  |errupt accumulat|
000003f0  6f 72 20 73 61 76 65 20  72 65 67 69 73 74 65 72  |or save register|
00000400  0d 01 86 22 50 48 41 20  5c 20 61 6e 64 20 70 75  |..."PHA \ and pu|
00000410  73 68 20 69 74 20 6f 6e  20 74 68 65 20 73 74 61  |sh it on the sta|
00000420  63 6b 0d 01 90 2e 4c 44  41 20 69 66 72 20 5c 20  |ck....LDA ifr \ |
00000430  6c 6f 61 64 20 73 79 73  74 65 6d 20 56 49 41 20  |load system VIA |
00000440  69 6e 74 65 72 72 75 70  74 20 73 74 61 74 75 73  |interrupt status|
00000450  0d 01 9a 22 42 50 4c 20  65 78 69 74 20 5c 20 65  |..."BPL exit \ e|
00000460  78 69 74 20 69 66 20 62  69 74 20 37 20 63 6c 65  |xit if bit 7 cle|
00000470  61 72 0d 01 a4 1d 80 20  23 26 30 38 20 5c 20 80  |ar..... #&08 \ .|
00000480  20 77 69 74 68 20 25 30  30 30 30 31 30 30 30 0d  | with %00001000.|
00000490  01 ae 2e 42 45 51 20 65  78 69 74 20 5c 20 65 78  |...BEQ exit \ ex|
000004a0  69 74 20 69 66 20 6e 6f  74 20 6c 69 67 68 74 20  |it if not light |
000004b0  70 65 6e 20 69 6e 74 65  72 72 75 70 74 0d 01 b8  |pen interrupt...|
000004c0  07 54 58 41 0d 01 c2 07  50 48 41 0d 01 cc 07 54  |.TXA....PHA....T|
000004d0  59 41 0d 01 d6 07 50 48  41 0d 01 e0 1d 4c 44 41  |YA....PHA....LDA|
000004e0  20 64 72 62 20 5c 20 63  6c 65 61 72 20 69 6e 74  | drb \ clear int|
000004f0  65 72 72 75 70 74 0d 01  ea 1e 50 48 41 20 5c 20  |errupt....PHA \ |
00000500  70 75 73 68 20 64 61 74  61 20 72 65 67 69 73 74  |push data regist|
00000510  65 72 20 42 0d 01 f4 1c  43 4c 44 20 5c 20 63 6c  |er B....CLD \ cl|
00000520  65 61 72 20 64 65 63 69  6d 61 6c 20 66 6c 61 67  |ear decimal flag|
00000530  0d 01 fe 2c 4c 44 59 20  73 63 72 65 65 6e 20 5c  |...,LDY screen \|
00000540  20 73 63 72 65 65 6e 20  6d 6f 64 65 20 69 6e 74  | screen mode int|
00000550  6f 20 59 20 72 65 67 69  73 74 65 72 0d 02 08 2e  |o Y register....|
00000560  4c 44 41 20 73 74 61 72  74 20 5c 20 73 63 72 65  |LDA start \ scre|
00000570  65 6e 20 73 74 61 72 74  20 61 64 64 72 65 73 73  |en start address|
00000580  2c 20 6c 6f 77 20 62 79  74 65 0d 02 12 0e 53 54  |, low byte....ST|
00000590  41 20 79 63 6f 6f 72 64  0d 02 1c 31 4c 44 41 20  |A ycoord...1LDA |
000005a0  73 74 61 72 74 2b 31 20  5c 20 73 63 72 65 65 6e  |start+1 \ screen|
000005b0  20 73 74 61 72 74 20 61  64 64 72 65 73 73 2c 20  | start address, |
000005c0  68 69 67 68 20 62 79 74  65 0d 02 26 10 53 54 41  |high byte..&.STA|
000005d0  20 79 63 6f 6f 72 64 2b  31 0d 02 30 1e 43 50 59  | ycoord+1..0.CPY|
000005e0  20 23 26 30 37 20 5c 20  69 73 20 74 68 69 73 20  | #&07 \ is this |
000005f0  6d 6f 64 65 20 37 3f 0d  02 3a 0d 42 45 51 20 6d  |mode 7?..:.BEQ m|
00000600  6f 64 65 37 0d 02 44 10  4c 53 52 20 79 63 6f 6f  |ode7..D.LSR ycoo|
00000610  72 64 2b 31 0d 02 4e 22  52 4f 52 20 79 63 6f 6f  |rd+1..N"ROR ycoo|
00000620  72 64 20 5c 20 73 74 61  72 74 20 61 64 64 72 65  |rd \ start addre|
00000630  73 73 20 81 20 32 0d 02  58 10 4c 53 52 20 79 63  |ss . 2..X.LSR yc|
00000640  6f 6f 72 64 2b 31 0d 02  62 22 52 4f 52 20 79 63  |oord+1..b"ROR yc|
00000650  6f 6f 72 64 20 5c 20 73  74 61 72 74 20 61 64 64  |oord \ start add|
00000660  72 65 73 73 20 81 20 34  0d 02 6c 10 4c 53 52 20  |ress . 4..l.LSR |
00000670  79 63 6f 6f 72 64 2b 31  0d 02 76 22 52 4f 52 20  |ycoord+1..v"ROR |
00000680  79 63 6f 6f 72 64 20 5c  20 73 74 61 72 74 20 61  |ycoord \ start a|
00000690  64 64 72 65 73 73 20 81  20 38 0d 02 80 2a 4a 4d  |ddress . 8...*JM|
000006a0  50 20 63 6f 6e 74 69 6e  75 65 20 5c 20 73 6b 69  |P continue \ ski|
000006b0  70 20 6d 6f 64 65 20 37  20 63 61 6c 63 75 6c 61  |p mode 7 calcula|
000006c0  74 69 6f 6e 0d 02 8a 0a  2e 6d 6f 64 65 37 0d 02  |tion.....mode7..|
000006d0  94 21 53 45 43 20 5c 20  70 72 65 70 61 72 65 20  |.!SEC \ prepare |
000006e0  66 6f 72 20 73 75 62 74  72 61 63 74 69 6f 6e 0d  |for subtraction.|
000006f0  02 9e 10 4c 44 41 20 79  63 6f 6f 72 64 2b 31 0d  |...LDA ycoord+1.|
00000700  02 a8 0c 53 42 43 20 23  26 35 34 0d 02 b2 34 53  |...SBC #&54...4S|
00000710  54 41 20 79 63 6f 6f 72  64 2b 31 20 5c 20 73 75  |TA ycoord+1 \ su|
00000720  62 74 72 61 63 74 20 26  35 34 30 30 20 66 72 6f  |btract &5400 fro|
00000730  6d 20 73 74 61 72 74 20  61 64 64 72 65 73 73 0d  |m start address.|
00000740  02 bc 0d 2e 63 6f 6e 74  69 6e 75 65 0d 02 c6 13  |....continue....|
00000750  4c 44 41 20 6f 66 66 73  65 74 6c 6f 77 2c 59 0d  |LDA offsetlow,Y.|
00000760  02 d0 1e 43 4c 43 20 5c  20 70 72 65 70 61 72 65  |...CLC \ prepare|
00000770  20 66 6f 72 20 61 64 64  69 74 69 6f 6e 0d 02 da  | for addition...|
00000780  23 41 44 43 20 79 63 6f  6f 72 64 20 5c 20 61 64  |#ADC ycoord \ ad|
00000790  64 20 74 72 69 6d 20 74  6f 20 6f 66 66 73 65 74  |d trim to offset|
000007a0  0d 02 e4 0e 53 54 41 20  79 63 6f 6f 72 64 0d 02  |....STA ycoord..|
000007b0  ee 0c 4c 44 41 20 23 26  30 30 0d 02 f8 10 41 44  |..LDA #&00....AD|
000007c0  43 20 79 63 6f 6f 72 64  2b 31 0d 03 02 10 53 54  |C ycoord+1....ST|
000007d0  41 20 79 63 6f 6f 72 64  2b 31 0d 03 0c 35 53 45  |A ycoord+1...5SE|
000007e0  43 20 5c 20 70 72 65 70  61 72 65 20 74 6f 20 73  |C \ prepare to s|
000007f0  75 62 74 72 61 63 74 20  6f 66 66 73 65 74 20 66  |ubtract offset f|
00000800  72 6f 6d 20 6c 70 20 72  65 67 69 73 74 65 72 0d  |rom lp register.|
00000810  03 16 2b 4c 44 58 20 23  26 31 31 20 5c 20 6c 69  |..+LDX #&11 \ li|
00000820  67 68 74 20 70 65 6e 20  72 65 67 69 73 74 65 72  |ght pen register|
00000830  2c 20 6c 6f 77 20 62 79  74 65 0d 03 20 26 53 54  |, low byte.. &ST|
00000840  58 20 73 68 65 69 6c 61  20 5c 20 36 38 34 35 20  |X sheila \ 6845 |
00000850  61 64 64 72 65 73 73 20  72 65 67 69 73 74 65 72  |address register|
00000860  0d 03 2a 25 4c 44 41 20  73 68 65 69 6c 61 2b 31  |..*%LDA sheila+1|
00000870  20 5c 20 36 38 34 35 20  64 61 74 61 20 72 65 67  | \ 6845 data reg|
00000880  69 73 74 65 72 0d 03 34  2a 53 42 43 20 79 63 6f  |ister..4*SBC yco|
00000890  6f 72 64 20 5c 20 73 75  62 74 72 61 63 74 20 6f  |ord \ subtract o|
000008a0  66 66 73 65 74 2c 20 6c  6f 77 20 62 79 74 65 0d  |ffset, low byte.|
000008b0  03 3e 22 53 54 41 20 79  63 6f 6f 72 64 20 5c 20  |.>"STA ycoord \ |
000008c0  6c 6f 77 20 62 79 74 65  20 2d 20 6f 66 66 73 65  |low byte - offse|
000008d0  74 0d 03 48 30 44 45 58  20 5c 20 58 20 3d 20 26  |t..H0DEX \ X = &|
000008e0  31 30 2c 20 6c 69 67 68  74 20 70 65 6e 20 72 65  |10, light pen re|
000008f0  67 69 73 74 65 72 2c 20  68 69 67 68 20 62 79 74  |gister, high byt|
00000900  65 0d 03 52 26 53 54 58  20 73 68 65 69 6c 61 20  |e..R&STX sheila |
00000910  5c 20 36 38 34 35 20 61  64 64 72 65 73 73 20 72  |\ 6845 address r|
00000920  65 67 69 73 74 65 72 0d  03 5c 25 4c 44 41 20 73  |egister..\%LDA s|
00000930  68 65 69 6c 61 2b 31 20  5c 20 36 38 34 35 20 64  |heila+1 \ 6845 d|
00000940  61 74 61 20 72 65 67 69  73 74 65 72 0d 03 66 2d  |ata register..f-|
00000950  53 42 43 20 79 63 6f 6f  72 64 2b 31 20 5c 20 73  |SBC ycoord+1 \ s|
00000960  75 62 74 72 61 63 74 20  6f 66 66 73 65 74 2c 20  |ubtract offset, |
00000970  68 69 67 68 20 62 79 74  65 0d 03 70 25 53 54 41  |high byte..p%STA|
00000980  20 79 63 6f 6f 72 64 2b  31 20 5c 20 68 69 67 68  | ycoord+1 \ high|
00000990  20 62 79 74 65 20 2d 20  6f 66 66 73 65 74 0d 03  | byte - offset..|
000009a0  7a 2a 4c 44 41 20 23 26  30 30 20 5c 20 70 72 65  |z*LDA #&00 \ pre|
000009b0  70 61 72 65 20 66 6f 72  20 31 36 20 62 69 74 20  |pare for 16 bit |
000009c0  64 69 76 69 73 69 6f 6e  0d 03 84 2b 53 54 41 20  |division...+STA |
000009d0  78 63 6f 6f 72 64 20 5c  20 63 6c 65 61 72 20 6c  |xcoord \ clear l|
000009e0  6f 77 20 70 61 72 74 69  61 6c 20 64 69 76 69 64  |ow partial divid|
000009f0  65 6e 64 0d 03 8e 09 2e  6e 65 78 74 0d 03 98 2d  |end.....next...-|
00000a00  41 53 4c 20 79 63 6f 6f  72 64 20 5c 20 73 68 69  |ASL ycoord \ shi|
00000a10  66 74 20 64 69 76 69 64  65 6e 64 2f 71 75 6f 74  |ft dividend/quot|
00000a20  69 65 6e 74 20 6c 65 66  74 0d 03 a2 2f 52 4f 4c  |ient left.../ROL|
00000a30  20 79 63 6f 6f 72 64 2b  31 20 5c 20 73 68 69 66  | ycoord+1 \ shif|
00000a40  74 20 64 69 76 69 64 65  6e 64 2f 71 75 6f 74 69  |t dividend/quoti|
00000a50  65 6e 74 20 6c 65 66 74  0d 03 ac 31 52 4f 4c 20  |ent left...1ROL |
00000a60  78 63 6f 6f 72 64 20 5c  20 73 68 69 66 74 20 62  |xcoord \ shift b|
00000a70  69 74 73 20 69 6e 74 6f  20 70 61 72 74 69 61 6c  |its into partial|
00000a80  20 64 69 76 69 64 65 6e  64 0d 03 b6 26 4c 44 41  | dividend...&LDA|
00000a90  20 78 63 6f 6f 72 64 20  5c 20 6c 6f 61 64 20 70  | xcoord \ load p|
00000aa0  61 72 74 69 61 6c 20 64  69 76 69 64 65 6e 64 0d  |artial dividend.|
00000ab0  03 c0 21 53 45 43 20 5c  20 70 72 65 70 61 72 65  |..!SEC \ prepare|
00000ac0  20 66 6f 72 20 73 75 62  74 72 61 63 74 69 6f 6e  | for subtraction|
00000ad0  0d 03 ca 22 53 42 43 20  77 69 64 74 68 2c 59 20  |..."SBC width,Y |
00000ae0  5c 20 73 75 62 74 72 61  63 74 20 64 69 76 69 73  |\ subtract divis|
00000af0  6f 72 0d 03 d4 2b 42 43  43 20 64 6f 6e 65 20 5c  |or...+BCC done \|
00000b00  20 62 72 61 6e 63 68 20  69 66 20 64 69 76 69 64  | branch if divid|
00000b10  65 6e 64 20 3c 20 64 69  76 69 73 6f 72 0d 03 de  |end < divisor...|
00000b20  23 49 4e 43 20 79 63 6f  6f 72 64 20 5c 20 69 6e  |#INC ycoord \ in|
00000b30  63 72 65 6d 65 6e 74 20  71 75 6f 74 69 65 6e 74  |crement quotient|
00000b40  0d 03 e8 2a 53 54 41 20  78 63 6f 6f 72 64 20 5c  |...*STA xcoord \|
00000b50  20 73 61 76 65 20 6e 65  77 20 70 61 72 74 69 61  | save new partia|
00000b60  6c 20 64 69 76 69 64 65  6e 64 0d 03 f2 09 2e 64  |l dividend.....d|
00000b70  6f 6e 65 0d 03 fc 1f 44  45 58 20 5c 20 64 65 63  |one....DEX \ dec|
00000b80  72 65 6d 65 6e 74 20 62  69 74 20 63 6f 75 6e 74  |rement bit count|
00000b90  65 72 0d 04 06 21 42 4e  45 20 6e 65 78 74 20 5c  |er...!BNE next \|
00000ba0  20 62 72 61 6e 63 68 20  66 6f 72 20 31 36 20 62  | branch for 16 b|
00000bb0  69 74 73 0d 04 10 23 4c  44 41 20 73 63 61 6c 65  |its...#LDA scale|
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