� >Develop.BI_DIdrive
#� ASSEMBLE A RELOCATABLE MODULE
<� To drive the single direction to bi-direction hardware
(� With SWIs
2
�_Bint
<�(24);~MS;" ";~ME
FI*KEY 1 OSCLI("*SAVE Develop.!PortMon.MakeBi "+STR$~MS+" "+STR$~ME) |M
P2*KEY 2 *SETTYPE Develop.!PortMon.MakeBi FFA |M
Z-*KEY 3 *RMLOAD Develop.!PortMon.MakeBi |M
d
n8*KEY 5 SYS&42EC1,2,0,&FFFFFFFF TO ,A%,B%:P.~A%,~B%|M
x*KEY 6 SYS&42EC1,2,
�#*KEY 7 ,0 TO ,A%,B%:P.~A%,~B%|M
�!*KEY 9 SYS&42EC1, 1,&FF,&FF|M
�"*KEY 10 SYS&42EC1, 1,&00,&FF|M
�-*KEY 11 SYS&42EC1,0 TO ,A%,B%:P.~A%,~B%|M
��
�� �_Bint
�� INITILISATION
�� CODE% 1800
�OS_WriteI=&100
�� A%=0 � 3 � 3
�P%=CODE%
�[
�
OPT A%

.MS \ �ULE START LABLE

EQUD 0      \ START CODE

$EQUD IC-MS  \ INITILISATION �SET

"#EQUD FC-MS  \ FINILISATION CODE

,EQUD 0      \ SERVICE CODE

6#EQUD TS-MS  \ TITLE STRING �SET

@ EQUD HS-MS  \ Ǔ STRING �SET

J$EQUD 0      \ COMMAND TABLE �SET

T EQUD &42EC0 \ SWI CHUNK BASE

^"EQUD PP-MS  \ SWI HANDLER CODE

h$EQUD 0      \ SWI DECODING TABLE

r#EQUD 0      \ SWI DECODING CODE

|"EQUD 0      \ � � TABLE MARKER

�.HS EQUS "Printer Port"

�EQUB 09

�GEQUS "0.10 (10 July 1995) Driver for single to Bi-directional Port"

�
EQUB 0

�	ALIGN

� .TS EQUS "BI-DI_Port_Driver"

�
EQUB 0

�	ALIGN

�

�.IC \ START CODE

�\ CLAIM MEMORY

�STMFD (13)!,{14} \ Ǚ �

�MOV R0,#6 \ CLAIM SPACE
MOV R3,#&4 \ AMOUNT � SPACE
#SWI "OS_Module" \ ask for space
STRVC R2,[R12]
&*LDMFD (13) !,{15} \ BACK FROM �ST CAME
0
:.FC \ FINILISATION CODE
DSTMFD (13)!,{14} \ Ǚ �
NMOV R0,#7 \ FREE SPACE
X LDR R2,[R12] \ ȒER � MEMORY
b"MOV R3,#&3E00 \ AMOUNT � SPACE
l"SWI "OS_Module" \ GIVE IT BACK
v*LDMFD (13) !,{15} \ BACK FROM �ST CAME
�
�*.PP \ MACHINE CODE � HANDLE �ER ACCESS
�
�LDR R12,[R12]
�CMP R11,#(EOJ - JT)/4
�ADDLO PC, PC, R11, LSL #2
�
B UNKN
�.JT
�	B PP0
�	B PP1
�.EOJ
�	.UNKN
�ADR R0,ErrTok
MOV R1, #0
MOV R2, #0
ADR R4, HS
 #SWI "XMessageTrans_ErrorLookup"
*,�RS  PC, R14, #&10000000\ #Overflow_Flag
4.ErrTok
>
EQUD &1E6
HEQUS "BadSWI"
R
EQUB 0
\	ALIGN
f\ Return Printer Address
p.PP0
z.MOV R0,#&3200000 \ Address of Printer Port
�ADD R0,R0,#&50000
�ADD R0,R0,#&10
�MOVS PC,R14
�
�\ Parallel port Operation
�.PP1
�STMFD R13!,{R3,R4,R5,R6}
�
CMP R0,#0
�
BEQ Rs
�
CMP R0,#1
�BEQ WDR
�
CMP R0,#2
�
BEQ CT
MOVS PC,R14

\Read status & data
$.Rs
..MOV R4,#&3200000 \ Address of Printer Port
8(ADD R0,R4,#&50000 \ Point to printer
B3MOV R5,#0 \ Register to accumulate Printer byte
L2MOV R6,#0 \ Register to accumulate Status byte
VMOV R1,#&67
`.nb
j,MOV R2,R1,ASL #16 \ Shift to top 16 bits
t+STR R2,[R0,#&10] \ Store it out to port
~
�MOV R5,R5,ASL #1
�MOV R6,R6,ASL #1
� LDRB R3,[R4,#&10] \ Get Busy
�� R3,R3,#1 \ Mask out busy
�)�R R5,R5,R3 \ Merge with printer byte
�
�LDRB R3,[R4,#&00] \ Get ACK
�� R3,R3,#&40
�MOV R3,R3,LSR #6
�(�R R6,R6,R3 \ Merge with status byte
�+SUB R1,R1,#1 \ Next multiplexer address
�
8TST R1,#8 \ Have we reached the end of all addresses

*BEQ nb    \ Do it again if we have not

MOV R1,R5

MOV R2,R6
($� R2,R2,#&80 \ Invert status bit
2
MOV R0,#0
<LDMFD R13!,{R3,R4,R5,R6}
FMOVS PC,R14
P
Z\ Write Data to printer
d.WDR
n.MOV R4,#&3200000 \ Address of Printer Port
xADD R4,R4,#&50000
�MOV R1,R1, ASL #16
�MOV R2,#&67
�MOV R2,R2,ASL #16
�.nb2
�&� R3,R1,#&800000 \ Isolate top bit
�$�R R3,R3,R2 \ Merge with address
�"STR R3,[R4,#&10] \ Output data
�!� R3,R3,#&DF0000 \ Strobe low
�STR R3,[R4,#&10]
�
�#�R R3,R3,#&200000 \ Strobe high
�STR R3,[R4,#&10]
�(MOV R1,R1,ASL #1 \ Slide to next bit
SUB R2,R2,#&10000
TST R2,#&80000
BEQ nb2
"LDMFD R13!,{R3,R4,R5,R6}
,MOVS PC,R14
6
@\ Read & Write control reg
J.CT
T>LDR R0,[R12] \ Get what has been written to Control before
^� R3,R2,R0
h'� R2,R3,R1 \ Now contains new value
r� R2,R2,#&FF
|#STR R2,[R12] \ Record new value
�
MOV R1,R2
�,� R1,R1,#&B \ Make some outputs inverted
�
�%\ Now write it to the multiplexer
�.MOV R4,#&3200000 \ Address of Printer Port
�ADD R4,R4,#&50000
�MOV R1,R1, ASL #16
�MOV R2,#&67
�MOV R2,R2,ASL #16
�.nb3
�-� R3,R1,#&800000 \ Isolate second top bit
�$�R R3,R3,R2 \ Merge with address
�"STR R3,[R4,#&10] \ Output data
!� R3,R3,#&BF0000 \ Strobe low
STR R3,[R4,#&10]

&
\Delay
0\MOV R6,#&400
:	\.DL3
D\STR R3,[R4,#&10]
N\SUBS R6,R6,#1
X\BNE DL3
b
l#�R R3,R3,#&400000 \ Strobe high
vSTR R3,[R4,#&10]
�(MOV R1,R1,ASL #1 \ Slide to next bit
�SUB R2,R2,#&10000
�TST R2,#&80000
�BEQ nb3
�
�\Put values in right place
�MOV R1,R0    \ Old value
�
MOV R0,#3
�LDR R2,[R12] \ New value
�LDMFD R13!,{R3,R4,R5,R6}
�MOVS PC,R14
�
�.ME \ LABLE � �ULE �
]
�
�
�

00000000  0d 00 0a 19 f4 20 3e 44  65 76 65 6c 6f 70 2e 42  |..... >Develop.B|
00000010  49 5f 44 49 64 72 69 76  65 0d 00 14 23 f4 20 41  |I_DIdrive...#. A|
00000020  53 53 45 4d 42 4c 45 20  41 20 52 45 4c 4f 43 41  |SSEMBLE A RELOCA|
00000030  54 41 42 4c 45 20 4d 4f  44 55 4c 45 0d 00 1e 3c  |TABLE MODULE...<|
00000040  f4 20 54 6f 20 64 72 69  76 65 20 74 68 65 20 73  |. To drive the s|
00000050  69 6e 67 6c 65 20 64 69  72 65 63 74 69 6f 6e 20  |ingle direction |
00000060  74 6f 20 62 69 2d 64 69  72 65 63 74 69 6f 6e 20  |to bi-direction |
00000070  68 61 72 64 77 61 72 65  0d 00 28 0f f4 20 57 69  |hardware..(.. Wi|
00000080  74 68 20 53 57 49 73 0d  00 32 0a f2 5f 42 69 6e  |th SWIs..2.._Bin|
00000090  74 0d 00 3c 16 f1 89 28  32 34 29 3b 7e 4d 53 3b  |t..<...(24);~MS;|
000000a0  22 20 22 3b 7e 4d 45 0d  00 46 49 2a 4b 45 59 20  |" ";~ME..FI*KEY |
000000b0  31 20 4f 53 43 4c 49 28  22 2a 53 41 56 45 20 44  |1 OSCLI("*SAVE D|
000000c0  65 76 65 6c 6f 70 2e 21  50 6f 72 74 4d 6f 6e 2e  |evelop.!PortMon.|
000000d0  4d 61 6b 65 42 69 20 22  2b 53 54 52 24 7e 4d 53  |MakeBi "+STR$~MS|
000000e0  2b 22 20 22 2b 53 54 52  24 7e 4d 45 29 20 7c 4d  |+" "+STR$~ME) |M|
000000f0  0d 00 50 32 2a 4b 45 59  20 32 20 2a 53 45 54 54  |..P2*KEY 2 *SETT|
00000100  59 50 45 20 44 65 76 65  6c 6f 70 2e 21 50 6f 72  |YPE Develop.!Por|
00000110  74 4d 6f 6e 2e 4d 61 6b  65 42 69 20 46 46 41 20  |tMon.MakeBi FFA |
00000120  7c 4d 0d 00 5a 2d 2a 4b  45 59 20 33 20 2a 52 4d  ||M..Z-*KEY 3 *RM|
00000130  4c 4f 41 44 20 44 65 76  65 6c 6f 70 2e 21 50 6f  |LOAD Develop.!Po|
00000140  72 74 4d 6f 6e 2e 4d 61  6b 65 42 69 20 7c 4d 0d  |rtMon.MakeBi |M.|
00000150  00 64 04 0d 00 6e 38 2a  4b 45 59 20 35 20 53 59  |.d...n8*KEY 5 SY|
00000160  53 26 34 32 45 43 31 2c  32 2c 30 2c 26 46 46 46  |S&42EC1,2,0,&FFF|
00000170  46 46 46 46 46 20 54 4f  20 2c 41 25 2c 42 25 3a  |FFFFF TO ,A%,B%:|
00000180  50 2e 7e 41 25 2c 7e 42  25 7c 4d 0d 00 78 17 2a  |P.~A%,~B%|M..x.*|
00000190  4b 45 59 20 36 20 53 59  53 26 34 32 45 43 31 2c  |KEY 6 SYS&42EC1,|
000001a0  32 2c 0d 00 82 23 2a 4b  45 59 20 37 20 2c 30 20  |2,...#*KEY 7 ,0 |
000001b0  54 4f 20 2c 41 25 2c 42  25 3a 50 2e 7e 41 25 2c  |TO ,A%,B%:P.~A%,|
000001c0  7e 42 25 7c 4d 0d 00 8c  21 2a 4b 45 59 20 39 20  |~B%|M...!*KEY 9 |
000001d0  53 59 53 26 34 32 45 43  31 2c 20 31 2c 26 46 46  |SYS&42EC1, 1,&FF|
000001e0  2c 26 46 46 7c 4d 0d 00  96 22 2a 4b 45 59 20 31  |,&FF|M..."*KEY 1|
000001f0  30 20 53 59 53 26 34 32  45 43 31 2c 20 31 2c 26  |0 SYS&42EC1, 1,&|
00000200  30 30 2c 26 46 46 7c 4d  0d 00 a0 2d 2a 4b 45 59  |00,&FF|M...-*KEY|
00000210  20 31 31 20 53 59 53 26  34 32 45 43 31 2c 30 20  | 11 SYS&42EC1,0 |
00000220  54 4f 20 2c 41 25 2c 42  25 3a 50 2e 7e 41 25 2c  |TO ,A%,B%:P.~A%,|
00000230  7e 42 25 7c 4d 0d 00 aa  05 e0 0d 00 b4 0c dd 20  |~B%|M.......... |
00000240  f2 5f 42 69 6e 74 0d 00  be 13 f4 20 49 4e 49 54  |._Bint..... INIT|
00000250  49 4c 49 53 41 54 49 4f  4e 0d 00 c8 10 de 20 43  |ILISATION..... C|
00000260  4f 44 45 25 20 31 38 30  30 0d 00 d2 12 4f 53 5f  |ODE% 1800....OS_|
00000270  57 72 69 74 65 49 3d 26  31 30 30 0d 00 dc 12 e3  |WriteI=&100.....|
00000280  20 41 25 3d 30 20 b8 20  33 20 88 20 33 0d 00 e6  | A%=0 . 3 . 3...|
00000290  0c 50 25 3d 43 4f 44 45  25 0d 00 f0 05 5b 0d 00  |.P%=CODE%....[..|
000002a0  fa 0a 4f 50 54 20 41 25  0d 01 04 1a 2e 4d 53 20  |..OPT A%.....MS |
000002b0  5c 20 83 55 4c 45 20 53  54 41 52 54 20 4c 41 42  |\ .ULE START LAB|
000002c0  4c 45 0d 01 0e 1c 45 51  55 44 20 30 20 20 20 20  |LE....EQUD 0    |
000002d0  20 20 5c 20 53 54 41 52  54 20 43 4f 44 45 0d 01  |  \ START CODE..|
000002e0  18 24 45 51 55 44 20 49  43 2d 4d 53 20 20 5c 20  |.$EQUD IC-MS  \ |
000002f0  49 4e 49 54 49 4c 49 53  41 54 49 4f 4e 20 87 53  |INITILISATION .S|
00000300  45 54 0d 01 22 23 45 51  55 44 20 46 43 2d 4d 53  |ET.."#EQUD FC-MS|
00000310  20 20 5c 20 46 49 4e 49  4c 49 53 41 54 49 4f 4e  |  \ FINILISATION|
00000320  20 43 4f 44 45 0d 01 2c  1e 45 51 55 44 20 30 20  | CODE..,.EQUD 0 |
00000330  20 20 20 20 20 5c 20 53  45 52 56 49 43 45 20 43  |     \ SERVICE C|
00000340  4f 44 45 0d 01 36 23 45  51 55 44 20 54 53 2d 4d  |ODE..6#EQUD TS-M|
00000350  53 20 20 5c 20 54 49 54  4c 45 20 53 54 52 49 4e  |S  \ TITLE STRIN|
00000360  47 20 87 53 45 54 0d 01  40 20 45 51 55 44 20 48  |G .SET..@ EQUD H|
00000370  53 2d 4d 53 20 20 5c 20  c7 93 20 53 54 52 49 4e  |S-MS  \ .. STRIN|
00000380  47 20 87 53 45 54 0d 01  4a 24 45 51 55 44 20 30  |G .SET..J$EQUD 0|
00000390  20 20 20 20 20 20 5c 20  43 4f 4d 4d 41 4e 44 20  |      \ COMMAND |
000003a0  54 41 42 4c 45 20 87 53  45 54 0d 01 54 20 45 51  |TABLE .SET..T EQ|
000003b0  55 44 20 26 34 32 45 43  30 20 5c 20 53 57 49 20  |UD &42EC0 \ SWI |
000003c0  43 48 55 4e 4b 20 42 41  53 45 0d 01 5e 22 45 51  |CHUNK BASE..^"EQ|
000003d0  55 44 20 50 50 2d 4d 53  20 20 5c 20 53 57 49 20  |UD PP-MS  \ SWI |
000003e0  48 41 4e 44 4c 45 52 20  43 4f 44 45 0d 01 68 24  |HANDLER CODE..h$|
000003f0  45 51 55 44 20 30 20 20  20 20 20 20 5c 20 53 57  |EQUD 0      \ SW|
00000400  49 20 44 45 43 4f 44 49  4e 47 20 54 41 42 4c 45  |I DECODING TABLE|
00000410  0d 01 72 23 45 51 55 44  20 30 20 20 20 20 20 20  |..r#EQUD 0      |
00000420  5c 20 53 57 49 20 44 45  43 4f 44 49 4e 47 20 43  |\ SWI DECODING C|
00000430  4f 44 45 0d 01 7c 22 45  51 55 44 20 30 20 20 20  |ODE..|"EQUD 0   |
00000440  20 20 20 5c 20 e0 20 ca  20 54 41 42 4c 45 20 4d  |   \ . . TABLE M|
00000450  41 52 4b 45 52 0d 01 86  1b 2e 48 53 20 45 51 55  |ARKER.....HS EQU|
00000460  53 20 22 50 72 69 6e 74  65 72 20 50 6f 72 74 22  |S "Printer Port"|
00000470  0d 01 90 0b 45 51 55 42  20 30 39 0d 01 9a 47 45  |....EQUB 09...GE|
00000480  51 55 53 20 22 30 2e 31  30 20 28 31 30 20 4a 75  |QUS "0.10 (10 Ju|
00000490  6c 79 20 31 39 39 35 29  20 44 72 69 76 65 72 20  |ly 1995) Driver |
000004a0  66 6f 72 20 73 69 6e 67  6c 65 20 74 6f 20 42 69  |for single to Bi|
000004b0  2d 64 69 72 65 63 74 69  6f 6e 61 6c 20 50 6f 72  |-directional Por|
000004c0  74 22 0d 01 a4 0a 45 51  55 42 20 30 0d 01 ae 09  |t"....EQUB 0....|
000004d0  41 4c 49 47 4e 0d 01 b8  20 2e 54 53 20 45 51 55  |ALIGN... .TS EQU|
000004e0  53 20 22 42 49 2d 44 49  5f 50 6f 72 74 5f 44 72  |S "BI-DI_Port_Dr|
000004f0  69 76 65 72 22 0d 01 c2  0a 45 51 55 42 20 30 0d  |iver"....EQUB 0.|
00000500  01 cc 09 41 4c 49 47 4e  0d 01 d6 04 0d 01 e0 14  |...ALIGN........|
00000510  2e 49 43 20 5c 20 53 54  41 52 54 20 43 4f 44 45  |.IC \ START CODE|
00000520  0d 01 ea 12 5c 20 43 4c  41 49 4d 20 4d 45 4d 4f  |....\ CLAIM MEMO|
00000530  52 59 0d 01 f4 1b 53 54  4d 46 44 20 28 31 33 29  |RY....STMFD (13)|
00000540  21 2c 7b 31 34 7d 20 5c  20 c7 99 20 f8 0d 01 fe  |!,{14} \ .. ....|
00000550  1b 4d 4f 56 20 52 30 2c  23 36 20 5c 20 43 4c 41  |.MOV R0,#6 \ CLA|
00000560  49 4d 20 53 50 41 43 45  0d 02 08 1f 4d 4f 56 20  |IM SPACE....MOV |
00000570  52 33 2c 23 26 34 20 5c  20 41 4d 4f 55 4e 54 20  |R3,#&4 \ AMOUNT |
00000580  ca 20 53 50 41 43 45 0d  02 12 23 53 57 49 20 22  |. SPACE...#SWI "|
00000590  4f 53 5f 4d 6f 64 75 6c  65 22 20 5c 20 61 73 6b  |OS_Module" \ ask|
000005a0  20 66 6f 72 20 73 70 61  63 65 0d 02 1c 12 53 54  | for space....ST|
000005b0  52 56 43 20 52 32 2c 5b  52 31 32 5d 0d 02 26 2a  |RVC R2,[R12]..&*|
000005c0  4c 44 4d 46 44 20 28 31  33 29 20 21 2c 7b 31 35  |LDMFD (13) !,{15|
000005d0  7d 20 5c 20 42 41 43 4b  20 46 52 4f 4d 20 c9 53  |} \ BACK FROM .S|
000005e0  54 20 43 41 4d 45 0d 02  30 04 0d 02 3a 1b 2e 46  |T CAME..0...:..F|
000005f0  43 20 5c 20 46 49 4e 49  4c 49 53 41 54 49 4f 4e  |C \ FINILISATION|
00000600  20 43 4f 44 45 0d 02 44  1b 53 54 4d 46 44 20 28  | CODE..D.STMFD (|
00000610  31 33 29 21 2c 7b 31 34  7d 20 5c 20 c7 99 20 f8  |13)!,{14} \ .. .|
00000620  0d 02 4e 1a 4d 4f 56 20  52 30 2c 23 37 20 5c 20  |..N.MOV R0,#7 \ |
00000630  46 52 45 45 20 53 50 41  43 45 0d 02 58 20 4c 44  |FREE SPACE..X LD|
00000640  52 20 52 32 2c 5b 52 31  32 5d 20 5c 20 c8 92 45  |R R2,[R12] \ ..E|
00000650  52 20 b8 20 4d 45 4d 4f  52 59 0d 02 62 22 4d 4f  |R . MEMORY..b"MO|
00000660  56 20 52 33 2c 23 26 33  45 30 30 20 5c 20 41 4d  |V R3,#&3E00 \ AM|
00000670  4f 55 4e 54 20 ca 20 53  50 41 43 45 0d 02 6c 22  |OUNT . SPACE..l"|
00000680  53 57 49 20 22 4f 53 5f  4d 6f 64 75 6c 65 22 20  |SWI "OS_Module" |
00000690  5c 20 47 49 56 45 20 49  54 20 42 41 43 4b 0d 02  |\ GIVE IT BACK..|
000006a0  76 2a 4c 44 4d 46 44 20  28 31 33 29 20 21 2c 7b  |v*LDMFD (13) !,{|
000006b0  31 35 7d 20 5c 20 42 41  43 4b 20 46 52 4f 4d 20  |15} \ BACK FROM |
000006c0  c9 53 54 20 43 41 4d 45  0d 02 80 04 0d 02 8a 2a  |.ST CAME.......*|
000006d0  2e 50 50 20 5c 20 4d 41  43 48 49 4e 45 20 43 4f  |.PP \ MACHINE CO|
000006e0  44 45 20 b8 20 48 41 4e  44 4c 45 20 f1 45 52 20  |DE . HANDLE .ER |
000006f0  41 43 43 45 53 53 0d 02  94 04 0d 02 9e 11 4c 44  |ACCESS........LD|
00000700  52 20 52 31 32 2c 5b 52  31 32 5d 0d 02 a8 19 43  |R R12,[R12]....C|
00000710  4d 50 20 52 31 31 2c 23  28 45 4f 4a 20 2d 20 4a  |MP R11,#(EOJ - J|
00000720  54 29 2f 34 0d 02 b2 1d  41 44 44 4c 4f 20 50 43  |T)/4....ADDLO PC|
00000730  2c 20 50 43 2c 20 52 31  31 2c 20 4c 53 4c 20 23  |, PC, R11, LSL #|
00000740  32 0d 02 bc 0a 42 20 55  4e 4b 4e 0d 02 c6 07 2e  |2....B UNKN.....|
00000750  4a 54 0d 02 d0 09 42 20  50 50 30 0d 02 da 09 42  |JT....B PP0....B|
00000760  20 50 50 31 0d 02 e4 08  2e 45 4f 4a 0d 02 ee 09  | PP1.....EOJ....|
00000770  2e 55 4e 4b 4e 0d 02 f8  11 41 44 52 20 52 30 2c  |.UNKN....ADR R0,|
00000780  45 72 72 54 6f 6b 0d 03  02 0e 4d 4f 56 20 52 31  |ErrTok....MOV R1|
00000790  2c 20 23 30 0d 03 0c 0e  4d 4f 56 20 52 32 2c 20  |, #0....MOV R2, |
000007a0  23 30 0d 03 16 0e 41 44  52 20 52 34 2c 20 48 53  |#0....ADR R4, HS|
000007b0  0d 03 20 23 53 57 49 20  22 58 4d 65 73 73 61 67  |.. #SWI "XMessag|
000007c0  65 54 72 61 6e 73 5f 45  72 72 6f 72 4c 6f 6f 6b  |eTrans_ErrorLook|
000007d0  75 70 22 0d 03 2a 2c 84  52 53 20 20 50 43 2c 20  |up"..*,.RS  PC, |
000007e0  52 31 34 2c 20 23 26 31  30 30 30 30 30 30 30 5c  |R14, #&10000000\|
000007f0  20 23 4f 76 65 72 66 6c  6f 77 5f 46 6c 61 67 0d  | #Overflow_Flag.|
00000800  03 34 0b 2e 45 72 72 54  6f 6b 0d 03 3e 0d 45 51  |.4..ErrTok..>.EQ|
00000810  55 44 20 26 31 45 36 0d  03 48 11 45 51 55 53 20  |UD &1E6..H.EQUS |
00000820  22 42 61 64 53 57 49 22  0d 03 52 0a 45 51 55 42  |"BadSWI"..R.EQUB|
00000830  20 30 0d 03 5c 09 41 4c  49 47 4e 0d 03 66 1c 5c  | 0..\.ALIGN..f.\|
00000840  20 52 65 74 75 72 6e 20  50 72 69 6e 74 65 72 20  | Return Printer |
00000850  41 64 64 72 65 73 73 0d  03 70 08 2e 50 50 30 0d  |Address..p..PP0.|
00000860  03 7a 2e 4d 4f 56 20 52  30 2c 23 26 33 32 30 30  |.z.MOV R0,#&3200|
00000870  30 30 30 20 5c 20 41 64  64 72 65 73 73 20 6f 66  |000 \ Address of|
00000880  20 50 72 69 6e 74 65 72  20 50 6f 72 74 0d 03 84  | Printer Port...|
00000890  15 41 44 44 20 52 30 2c  52 30 2c 23 26 35 30 30  |.ADD R0,R0,#&500|
000008a0  30 30 0d 03 8e 12 41 44  44 20 52 30 2c 52 30 2c  |00....ADD R0,R0,|
000008b0  23 26 31 30 0d 03 98 0f  4d 4f 56 53 20 50 43 2c  |#&10....MOVS PC,|
000008c0  52 31 34 0d 03 a2 04 0d  03 ac 1d 5c 20 50 61 72  |R14........\ Par|
000008d0  61 6c 6c 65 6c 20 70 6f  72 74 20 4f 70 65 72 61  |allel port Opera|
000008e0  74 69 6f 6e 0d 03 b6 08  2e 50 50 31 0d 03 c0 1c  |tion.....PP1....|
000008f0  53 54 4d 46 44 20 52 31  33 21 2c 7b 52 33 2c 52  |STMFD R13!,{R3,R|
00000900  34 2c 52 35 2c 52 36 7d  0d 03 ca 0d 43 4d 50 20  |4,R5,R6}....CMP |
00000910  52 30 2c 23 30 0d 03 d4  0a 42 45 51 20 52 73 0d  |R0,#0....BEQ Rs.|
00000920  03 de 0d 43 4d 50 20 52  30 2c 23 31 0d 03 e8 0b  |...CMP R0,#1....|
00000930  42 45 51 20 57 44 52 0d  03 f2 0d 43 4d 50 20 52  |BEQ WDR....CMP R|
00000940  30 2c 23 32 0d 03 fc 0a  42 45 51 20 43 54 0d 04  |0,#2....BEQ CT..|
00000950  06 0f 4d 4f 56 53 20 50  43 2c 52 31 34 0d 04 10  |..MOVS PC,R14...|
00000960  04 0d 04 1a 17 5c 52 65  61 64 20 73 74 61 74 75  |.....\Read statu|
00000970  73 20 26 20 64 61 74 61  0d 04 24 07 2e 52 73 0d  |s & data..$..Rs.|
00000980  04 2e 2e 4d 4f 56 20 52  34 2c 23 26 33 32 30 30  |...MOV R4,#&3200|
00000990  30 30 30 20 5c 20 41 64  64 72 65 73 73 20 6f 66  |000 \ Address of|
000009a0  20 50 72 69 6e 74 65 72  20 50 6f 72 74 0d 04 38  | Printer Port..8|
000009b0  28 41 44 44 20 52 30 2c  52 34 2c 23 26 35 30 30  |(ADD R0,R4,#&500|
000009c0  30 30 20 5c 20 50 6f 69  6e 74 20 74 6f 20 70 72  |00 \ Point to pr|
000009d0  69 6e 74 65 72 0d 04 42  33 4d 4f 56 20 52 35 2c  |inter..B3MOV R5,|
000009e0  23 30 20 5c 20 52 65 67  69 73 74 65 72 20 74 6f  |#0 \ Register to|
000009f0  20 61 63 63 75 6d 75 6c  61 74 65 20 50 72 69 6e  | accumulate Prin|
00000a00  74 65 72 20 62 79 74 65  0d 04 4c 32 4d 4f 56 20  |ter byte..L2MOV |
00000a10  52 36 2c 23 30 20 5c 20  52 65 67 69 73 74 65 72  |R6,#0 \ Register|
00000a20  20 74 6f 20 61 63 63 75  6d 75 6c 61 74 65 20 53  | to accumulate S|
00000a30  74 61 74 75 73 20 62 79  74 65 0d 04 56 0f 4d 4f  |tatus byte..V.MO|
00000a40  56 20 52 31 2c 23 26 36  37 0d 04 60 07 2e 6e 62  |V R1,#&67..`..nb|
00000a50  0d 04 6a 2c 4d 4f 56 20  52 32 2c 52 31 2c 41 53  |..j,MOV R2,R1,AS|
00000a60  4c 20 23 31 36 20 5c 20  53 68 69 66 74 20 74 6f  |L #16 \ Shift to|
00000a70  20 74 6f 70 20 31 36 20  62 69 74 73 0d 04 74 2b  | top 16 bits..t+|
00000a80  53 54 52 20 52 32 2c 5b  52 30 2c 23 26 31 30 5d  |STR R2,[R0,#&10]|
00000a90  20 5c 20 53 74 6f 72 65  20 69 74 20 6f 75 74 20  | \ Store it out |
00000aa0  74 6f 20 70 6f 72 74 0d  04 7e 04 0d 04 88 14 4d  |to port..~.....M|
00000ab0  4f 56 20 52 35 2c 52 35  2c 41 53 4c 20 23 31 0d  |OV R5,R5,ASL #1.|
00000ac0  04 92 14 4d 4f 56 20 52  36 2c 52 36 2c 41 53 4c  |...MOV R6,R6,ASL|
00000ad0  20 23 31 0d 04 9c 20 4c  44 52 42 20 52 33 2c 5b  | #1... LDRB R3,[|
00000ae0  52 34 2c 23 26 31 30 5d  20 5c 20 47 65 74 20 42  |R4,#&10] \ Get B|
00000af0  75 73 79 0d 04 a6 1e 80  20 52 33 2c 52 33 2c 23  |usy..... R3,R3,#|
00000b00  31 20 5c 20 4d 61 73 6b  20 6f 75 74 20 62 75 73  |1 \ Mask out bus|
00000b10  79 0d 04 b0 29 84 52 20  52 35 2c 52 35 2c 52 33  |y...).R R5,R5,R3|
00000b20  20 5c 20 4d 65 72 67 65  20 77 69 74 68 20 70 72  | \ Merge with pr|
00000b30  69 6e 74 65 72 20 62 79  74 65 0d 04 ba 04 0d 04  |inter byte......|
00000b40  c4 1f 4c 44 52 42 20 52  33 2c 5b 52 34 2c 23 26  |..LDRB R3,[R4,#&|
00000b50  30 30 5d 20 5c 20 47 65  74 20 41 43 4b 0d 04 ce  |00] \ Get ACK...|
00000b60  10 80 20 52 33 2c 52 33  2c 23 26 34 30 0d 04 d8  |.. R3,R3,#&40...|
00000b70  14 4d 4f 56 20 52 33 2c  52 33 2c 4c 53 52 20 23  |.MOV R3,R3,LSR #|
00000b80  36 0d 04 e2 28 84 52 20  52 36 2c 52 36 2c 52 33  |6...(.R R6,R6,R3|
00000b90  20 5c 20 4d 65 72 67 65  20 77 69 74 68 20 73 74  | \ Merge with st|
00000ba0  61 74 75 73 20 62 79 74  65 0d 04 ec 2b 53 55 42  |atus byte...+SUB|
00000bb0  20 52 31 2c 52 31 2c 23  31 20 5c 20 4e 65 78 74  | R1,R1,#1 \ Next|
00000bc0  20 6d 75 6c 74 69 70 6c  65 78 65 72 20 61 64 64  | multiplexer add|
00000bd0  72 65 73 73 0d 04 f6 04  0d 05 00 38 54 53 54 20  |ress.......8TST |
00000be0  52 31 2c 23 38 20 5c 20  48 61 76 65 20 77 65 20  |R1,#8 \ Have we |
00000bf0  72 65 61 63 68 65 64 20  74 68 65 20 65 6e 64 20  |reached the end |
00000c00  6f 66 20 61 6c 6c 20 61  64 64 72 65 73 73 65 73  |of all addresses|
00000c10  0d 05 0a 2a 42 45 51 20  6e 62 20 20 20 20 5c 20  |...*BEQ nb    \ |
00000c20  44 6f 20 69 74 20 61 67  61 69 6e 20 69 66 20 77  |Do it again if w|
00000c30  65 20 68 61 76 65 20 6e  6f 74 0d 05 14 0d 4d 4f  |e have not....MO|
00000c40  56 20 52 31 2c 52 35 0d  05 1e 0d 4d 4f 56 20 52  |V R1,R5....MOV R|
00000c50  32 2c 52 36 0d 05 28 24  82 20 52 32 2c 52 32 2c  |2,R6..($. R2,R2,|
00000c60  23 26 38 30 20 5c 20 49  6e 76 65 72 74 20 73 74  |#&80 \ Invert st|
00000c70  61 74 75 73 20 62 69 74  0d 05 32 0d 4d 4f 56 20  |atus bit..2.MOV |
00000c80  52 30 2c 23 30 0d 05 3c  1c 4c 44 4d 46 44 20 52  |R0,#0..<.LDMFD R|
00000c90  31 33 21 2c 7b 52 33 2c  52 34 2c 52 35 2c 52 36  |13!,{R3,R4,R5,R6|
00000ca0  7d 0d 05 46 0f 4d 4f 56  53 20 50 43 2c 52 31 34  |}..F.MOVS PC,R14|
00000cb0  0d 05 50 04 0d 05 5a 1b  5c 20 57 72 69 74 65 20  |..P...Z.\ Write |
00000cc0  44 61 74 61 20 74 6f 20  70 72 69 6e 74 65 72 0d  |Data to printer.|
00000cd0  05 64 08 2e 57 44 52 0d  05 6e 2e 4d 4f 56 20 52  |.d..WDR..n.MOV R|
00000ce0  34 2c 23 26 33 32 30 30  30 30 30 20 5c 20 41 64  |4,#&3200000 \ Ad|
00000cf0  64 72 65 73 73 20 6f 66  20 50 72 69 6e 74 65 72  |dress of Printer|
00000d00  20 50 6f 72 74 0d 05 78  15 41 44 44 20 52 34 2c  | Port..x.ADD R4,|
00000d10  52 34 2c 23 26 35 30 30  30 30 0d 05 82 16 4d 4f  |R4,#&50000....MO|
00000d20  56 20 52 31 2c 52 31 2c  20 41 53 4c 20 23 31 36  |V R1,R1, ASL #16|
00000d30  0d 05 8c 0f 4d 4f 56 20  52 32 2c 23 26 36 37 0d  |....MOV R2,#&67.|
00000d40  05 96 15 4d 4f 56 20 52  32 2c 52 32 2c 41 53 4c  |...MOV R2,R2,ASL|
00000d50  20 23 31 36 0d 05 a0 08  2e 6e 62 32 0d 05 aa 26  | #16.....nb2...&|
00000d60  80 20 52 33 2c 52 31 2c  23 26 38 30 30 30 30 30  |. R3,R1,#&800000|
00000d70  20 5c 20 49 73 6f 6c 61  74 65 20 74 6f 70 20 62  | \ Isolate top b|
00000d80  69 74 0d 05 b4 24 84 52  20 52 33 2c 52 33 2c 52  |it...$.R R3,R3,R|
00000d90  32 20 5c 20 4d 65 72 67  65 20 77 69 74 68 20 61  |2 \ Merge with a|
00000da0  64 64 72 65 73 73 0d 05  be 22 53 54 52 20 52 33  |ddress..."STR R3|
00000db0  2c 5b 52 34 2c 23 26 31  30 5d 20 5c 20 4f 75 74  |,[R4,#&10] \ Out|
00000dc0  70 75 74 20 64 61 74 61  0d 05 c8 21 80 20 52 33  |put data...!. R3|
00000dd0  2c 52 33 2c 23 26 44 46  30 30 30 30 20 5c 20 53  |,R3,#&DF0000 \ S|
00000de0  74 72 6f 62 65 20 6c 6f  77 0d 05 d2 14 53 54 52  |trobe low....STR|
00000df0  20 52 33 2c 5b 52 34 2c  23 26 31 30 5d 0d 05 dc  | R3,[R4,#&10]...|
00000e00  04 0d 05 e6 23 84 52 20  52 33 2c 52 33 2c 23 26  |....#.R R3,R3,#&|
00000e10  32 30 30 30 30 30 20 5c  20 53 74 72 6f 62 65 20  |200000 \ Strobe |
00000e20  68 69 67 68 0d 05 f0 14  53 54 52 20 52 33 2c 5b  |high....STR R3,[|
00000e30  52 34 2c 23 26 31 30 5d  0d 05 fa 28 4d 4f 56 20  |R4,#&10]...(MOV |
00000e40  52 31 2c 52 31 2c 41 53  4c 20 23 31 20 5c 20 53  |R1,R1,ASL #1 \ S|
00000e50  6c 69 64 65 20 74 6f 20  6e 65 78 74 20 62 69 74  |lide to next bit|
00000e60  0d 06 04 15 53 55 42 20  52 32 2c 52 32 2c 23 26  |....SUB R2,R2,#&|
00000e70  31 30 30 30 30 0d 06 0e  12 54 53 54 20 52 32 2c  |10000....TST R2,|
00000e80  23 26 38 30 30 30 30 0d  06 18 0b 42 45 51 20 6e  |#&80000....BEQ n|
00000e90  62 32 0d 06 22 1c 4c 44  4d 46 44 20 52 31 33 21  |b2..".LDMFD R13!|
00000ea0  2c 7b 52 33 2c 52 34 2c  52 35 2c 52 36 7d 0d 06  |,{R3,R4,R5,R6}..|
00000eb0  2c 0f 4d 4f 56 53 20 50  43 2c 52 31 34 0d 06 36  |,.MOVS PC,R14..6|
00000ec0  04 0d 06 40 1e 5c 20 52  65 61 64 20 26 20 57 72  |...@.\ Read & Wr|
00000ed0  69 74 65 20 63 6f 6e 74  72 6f 6c 20 72 65 67 0d  |ite control reg.|
00000ee0  06 4a 07 2e 43 54 0d 06  54 3e 4c 44 52 20 52 30  |.J..CT..T>LDR R0|
00000ef0  2c 5b 52 31 32 5d 20 5c  20 47 65 74 20 77 68 61  |,[R12] \ Get wha|
00000f00  74 20 68 61 73 20 62 65  65 6e 20 77 72 69 74 74  |t has been writt|
00000f10  65 6e 20 74 6f 20 43 6f  6e 74 72 6f 6c 20 62 65  |en to Control be|
00000f20  66 6f 72 65 0d 06 5e 0e  80 20 52 33 2c 52 32 2c  |fore..^.. R3,R2,|
00000f30  52 30 0d 06 68 27 82 20  52 32 2c 52 33 2c 52 31  |R0..h'. R2,R3,R1|
00000f40  20 5c 20 4e 6f 77 20 63  6f 6e 74 61 69 6e 73 20  | \ Now contains |
00000f50  6e 65 77 20 76 61 6c 75  65 0d 06 72 10 80 20 52  |new value..r.. R|
00000f60  32 2c 52 32 2c 23 26 46  46 0d 06 7c 23 53 54 52  |2,R2,#&FF..|#STR|
00000f70  20 52 32 2c 5b 52 31 32  5d 20 5c 20 52 65 63 6f  | R2,[R12] \ Reco|
00000f80  72 64 20 6e 65 77 20 76  61 6c 75 65 0d 06 86 0d  |rd new value....|
00000f90  4d 4f 56 20 52 31 2c 52  32 0d 06 90 2c 82 20 52  |MOV R1,R2...,. R|
00000fa0  31 2c 52 31 2c 23 26 42  20 5c 20 4d 61 6b 65 20  |1,R1,#&B \ Make |
00000fb0  73 6f 6d 65 20 6f 75 74  70 75 74 73 20 69 6e 76  |some outputs inv|
00000fc0  65 72 74 65 64 0d 06 9a  04 0d 06 a4 25 5c 20 4e  |erted.......%\ N|
00000fd0  6f 77 20 77 72 69 74 65  20 69 74 20 74 6f 20 74  |ow write it to t|
00000fe0  68 65 20 6d 75 6c 74 69  70 6c 65 78 65 72 0d 06  |he multiplexer..|
00000ff0  ae 2e 4d 4f 56 20 52 34  2c 23 26 33 32 30 30 30  |..MOV R4,#&32000|
00001000  30 30 20 5c 20 41 64 64  72 65 73 73 20 6f 66 20  |00 \ Address of |
00001010  50 72 69 6e 74 65 72 20  50 6f 72 74 0d 06 b8 15  |Printer Port....|
00001020  41 44 44 20 52 34 2c 52  34 2c 23 26 35 30 30 30  |ADD R4,R4,#&5000|
00001030  30 0d 06 c2 16 4d 4f 56  20 52 31 2c 52 31 2c 20  |0....MOV R1,R1, |
00001040  41 53 4c 20 23 31 36 0d  06 cc 0f 4d 4f 56 20 52  |ASL #16....MOV R|
00001050  32 2c 23 26 36 37 0d 06  d6 15 4d 4f 56 20 52 32  |2,#&67....MOV R2|
00001060  2c 52 32 2c 41 53 4c 20  23 31 36 0d 06 e0 08 2e  |,R2,ASL #16.....|
00001070  6e 62 33 0d 06 ea 2d 80  20 52 33 2c 52 31 2c 23  |nb3...-. R3,R1,#|
00001080  26 38 30 30 30 30 30 20  5c 20 49 73 6f 6c 61 74  |&800000 \ Isolat|
00001090  65 20 73 65 63 6f 6e 64  20 74 6f 70 20 62 69 74  |e second top bit|
000010a0  0d 06 f4 24 84 52 20 52  33 2c 52 33 2c 52 32 20  |...$.R R3,R3,R2 |
000010b0  5c 20 4d 65 72 67 65 20  77 69 74 68 20 61 64 64  |\ Merge with add|
000010c0  72 65 73 73 0d 06 fe 22  53 54 52 20 52 33 2c 5b  |ress..."STR R3,[|
000010d0  52 34 2c 23 26 31 30 5d  20 5c 20 4f 75 74 70 75  |R4,#&10] \ Outpu|
000010e0  74 20 64 61 74 61 0d 07  08 21 80 20 52 33 2c 52  |t data...!. R3,R|
000010f0  33 2c 23 26 42 46 30 30  30 30 20 5c 20 53 74 72  |3,#&BF0000 \ Str|
00001100  6f 62 65 20 6c 6f 77 0d  07 12 14 53 54 52 20 52  |obe low....STR R|
00001110  33 2c 5b 52 34 2c 23 26  31 30 5d 0d 07 1c 04 0d  |3,[R4,#&10].....|
00001120  07 26 0a 5c 44 65 6c 61  79 0d 07 30 11 5c 4d 4f  |.&.\Delay..0.\MO|
00001130  56 20 52 36 2c 23 26 34  30 30 0d 07 3a 09 5c 2e  |V R6,#&400..:.\.|
00001140  44 4c 33 0d 07 44 15 5c  53 54 52 20 52 33 2c 5b  |DL3..D.\STR R3,[|
00001150  52 34 2c 23 26 31 30 5d  0d 07 4e 12 5c 53 55 42  |R4,#&10]..N.\SUB|
00001160  53 20 52 36 2c 52 36 2c  23 31 0d 07 58 0c 5c 42  |S R6,R6,#1..X.\B|
00001170  4e 45 20 44 4c 33 0d 07  62 04 0d 07 6c 23 84 52  |NE DL3..b...l#.R|
00001180  20 52 33 2c 52 33 2c 23  26 34 30 30 30 30 30 20  | R3,R3,#&400000 |
00001190  5c 20 53 74 72 6f 62 65  20 68 69 67 68 0d 07 76  |\ Strobe high..v|
000011a0  14 53 54 52 20 52 33 2c  5b 52 34 2c 23 26 31 30  |.STR R3,[R4,#&10|
000011b0  5d 0d 07 80 28 4d 4f 56  20 52 31 2c 52 31 2c 41  |]...(MOV R1,R1,A|
000011c0  53 4c 20 23 31 20 5c 20  53 6c 69 64 65 20 74 6f  |SL #1 \ Slide to|
000011d0  20 6e 65 78 74 20 62 69  74 0d 07 8a 15 53 55 42  | next bit....SUB|
000011e0  20 52 32 2c 52 32 2c 23  26 31 30 30 30 30 0d 07  | R2,R2,#&10000..|
000011f0  94 12 54 53 54 20 52 32  2c 23 26 38 30 30 30 30  |..TST R2,#&80000|
00001200  0d 07 9e 0b 42 45 51 20  6e 62 33 0d 07 a8 04 0d  |....BEQ nb3.....|
00001210  07 b2 1e 5c 50 75 74 20  76 61 6c 75 65 73 20 69  |...\Put values i|
00001220  6e 20 72 69 67 68 74 20  70 6c 61 63 65 0d 07 bc  |n right place...|
00001230  1c 4d 4f 56 20 52 31 2c  52 30 20 20 20 20 5c 20  |.MOV R1,R0    \ |
00001240  4f 6c 64 20 76 61 6c 75  65 0d 07 c6 0d 4d 4f 56  |Old value....MOV|
00001250  20 52 30 2c 23 33 0d 07  d0 1c 4c 44 52 20 52 32  | R0,#3....LDR R2|
00001260  2c 5b 52 31 32 5d 20 5c  20 4e 65 77 20 76 61 6c  |,[R12] \ New val|
00001270  75 65 0d 07 da 1c 4c 44  4d 46 44 20 52 31 33 21  |ue....LDMFD R13!|
00001280  2c 7b 52 33 2c 52 34 2c  52 35 2c 52 36 7d 0d 07  |,{R3,R4,R5,R6}..|
00001290  e4 0f 4d 4f 56 53 20 50  43 2c 52 31 34 0d 07 ee  |..MOVS PC,R14...|
000012a0  04 0d 07 f8 18 2e 4d 45  20 5c 20 4c 41 42 4c 45  |......ME \ LABLE|
000012b0  20 e3 20 83 55 4c 45 20  e0 0d 08 02 05 5d 0d 08  | . .ULE .....]..|
000012c0  0c 05 ed 0d 08 16 05 e1  0d ff                    |..........|
000012ca