IBM AT 5170 Technical Reference page 311

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IBM Personal Computer MACRO Assembler Verston 2.00 1-2
PRT ------ 06/10/85 PRINTER ADAPTER 8[OS
06-10-85
115 0055 8-40: SEND STR08E PULSE
116005558
POP 8X RESTORE (BX) WITH TIMEOUT COUNT
1 11 0056 80 00
"OV
AL,OOH
SET THE STROBE LOW 181 T ON I
118 0058-42
INC OX OUTPUT STR08E TO CONTROL PORT
119 0059 FA CL! PREVENT I NTERRUPT PULSE STRETCH [NG
120 005A EE
OUT OX,AL OUTpUT STROBE BIT
>
Ius < 5\,/s
121 0058 E8 00
e"p
'.2
110
DELAY TO ALLOW FOR LINE LOADING
122 0050 E8 00
e"p
AND FOR CORRECT PULSE WIDTH
"2
123 005F 80 OC
"OV
AL,OCH
SET THE -STR08E HIGH
12-4 0061
EE
OUT OX,AL
125 0062 F8
S1l
INTERRUPTS 8ACK ON
126 0063 58
POP AX RECOVER THE OUTPUT CHAR
121
126
PRINTER STATUS
129
130 006-4 850 :
131 006-4
PUSH AX SAVE (All REGISTER
132 0065
860 :
133 0065 88 94 0008 R
MOV OX,IPPRINTER 8ASE[SI
J
GET PRINTER ATTACHMENT 8ASE ADDRESS
134 0069 42
I
NC OX - PO I NT TO CONTROL PORT
135 006A EC
IN AL,DX PRE-CHARGE +8USY LINE IF FLOATING
136 0068 EC
IN AL,DX GET PR INTER STATUS HARDWARE 81 TS
137 006C 81. EO
MOV AH,AL
SAVE
138 006E 80 E4
AND AH,OF8H TURN OFF UNUSED BITS
139 0011
B70:
140 0011 5A
POP OX
RECOVER (AL) REG I S TER
141 0012 8A C2 MOV AL,DL MOVE CHARACTER
r
NTO (AL I
1-42 001-4 80 F4 48
XOR AH,48H FLIP A COUPLE OF 81TS
143 0077 E8 AC
....IMP 810 RETURN FROM ROUTINE WITH STATUS IN AH
144
145
;
-----
INITIALIZE THE PRINTER PORT
146
147 0019 860:
148 0019 50
PUSH AX SAVE I ALI
149 001A-42
INC OX PO I NT TO OUTPUT PORT
150 0018 42
INC OX
151 001C BO 08
"OV
AL,8
SET INIT LINE LOW
152 001E EE OUT DX,AL
153 001F 88 OFAO
"OV
AX,1000-4 ADJUST FOR INITIALIZATION DELAY LOOP
154 0082 B90:
INIT LOOP
155 0082 48
DEC AX
LOOP-FOR RESET TO TAKE
!
56 0083 15 FD
eNZ 890 INIT LOOP
151 0085 80 OC
"OV
AL,OCH
NO
INTERRUPTS, NON AUTO LF. [NIT HIGH
158 0081 EE
OUT OX,AL
159 0088 E8 08
e"p 860
, EXIT THROUGH STATUS ROUTINE
160
161 008A PRINTER 10 I ENDP
162
163 0081.
CODE ENDS
164
END
PRT 5-139