IBM 5150 - Page 168

LOC OBJ LINE
SOURCE
EHI FEee 3254 DEC AH
I TEST fOR (AH)=2
EFn 7428 32:55 JZ 8S
; PRINTER STATUS
EFF5
3256
81:
; RETURN
EFF5 58 3257 POP BX
£FFb 59 3258
POP CX
EFn Sf
]259 POP
SI
I RECOVER REGISTERS
EFF8 5A
3260 POP
OX
J RECOVER REGISTERS
EFF9 IF
3261 POP OS
EFFA CF 3262
IRET
~
3263
3264
j------ PRINT TIlE CHARACTER IN (ALI
3265
EFFS 3266 82:
EFFB 50 3267 PUSH
AX
I SAVE VALUE TO PRINT
EFFC EE
3268 OUT ax,AL ; OUTPUT CHAR TO PORT
EFFO 42 3269
INC OX
; POINT TO 51 ATUS PORT
EFFE
3270
B3:
EFFE 26C9 3271
SUB
eX,ex I WAIT_BUSY
FOOD
3272 B3_1;
FOO~ EC
3273
IN AL,DX
; GET STATUS
FOOl 8AEO 3274 HOV
AH,AL ; STATUS TO AH ALSO
F003 .1.860 3275
TEST
"L
,
80H
; IS THE PRINTER CURREHTL Y BUSY
FODS 750E 3276
JNZ 8.
i OLrCSTROBe
FOOl ElF7
3277
LOOP
83_1
; TRY AGAIN
F009 FEte
]278
DEC
Bl
; DROP LOOP COUNT
Fooe 75FI 3279
JHZ .3 ; GO TILL TIMEOUT ENDS
FOOD 80CC01 3280
OR AH,I ; SET ERROR FLAG
F010 80E4F9
3281
AND
AH.OF9H
;
TURN OFF THE OTHER BITS
FOB EBB
3282
JHP
SHORT 87
; RETURN WITH ERROR FLAG SET
F015
3283 B4:
; OUT_STROBE
F015 BOOD 3284
HOY AL,OCH ; SET THE STROBE HIGH
F017 42 3285
INC OX ; STROBE IS BIT 0 OF PORT C OF 8255
F018 EE 3286
OUT
OX.Al
F019 BoDe
3287 HOV
Al,OCH ; SET THE STROBE lOW
FOlB EE
3288
O\JT OX,Al
FDIC 58
3289
POP AX
; RECOVER THE OUTPUT CHAR
3290
3291
;~~---- PRINTER STATUS
3292
~
fOlD
3293 85:
FOlD 50
3294
PUSH AX
I SAVE At REG
FOIE
3295 B6:
FOIE 8B5408 3296
HOV
OX I ~INTER_eASE [SI J
F021 42
3297
INC ox
F022 EC 3298
IN
Al.OX ; GET ~INTER STATUS
F023 8AEO
3299
HOV AH,AL
F025 80E4F8
3300
AND AH
,
OF8H
I TURN OFF UNUSED BITS
F028
3301
87:
; STATUS_SET
F028 SA
3302
POP OX ; RECOVER AL REG
F029 8 ... C2
3303
HOV
Al,Ol
; GET CHARACTER INTO Al
F028 80F448
3304
XOR AH,48H ; flIP A COUPLE OF BITS
F02E fBC5
3305
JHP 8,
; RETURN FROM ROUTINE
3306
3307
; ~---~- INITIALIZE THE PRINTER PORT
3308
F030
3309
B8:
F030 50
HIO
PUSH AX
I SAVE Al
F031 42
H11
INC OX
I POltfT TO OUTPUT PORT
F032 42
3312
INC
OX
F033 BD08
3313
HOV
Al.8 I SET INIT LINE LOW
F035 EE
3314
OUT DX,Al
F036 B8E803
3315
HOV AX,lOOO
F039
3316
B9:
i INIT_lOOP
F039 48
3317
DEC AX
; LOOP FOR RESET TO TAKE
F03A 75FD
3318 JNZ
8. I INIT_LOOP
F03C BOOC
3319
HOV AL,OCH
;
NO INTERRUPTS. NON AUTO LF.
3320
,
INIT HIGH
F03E
EE
3321
OUT DX •• U
F03F EBDD
3322
JHP .6
I PRT_STATUS_l
~
3323
PRINTER_IO
ENDP
3324
F041 62El
3325
e,
Ow
c,.
I RETURN ADDRESS FOR DUH'I1Y STACK
3326
3327
; ~~~ INT 1 0 -----_~ _____________________ ~ _____ ~ __ ~ _______________________
3328
; VIDEO_IO
3329
THESE ROUTINES PROVIDE THE CRT INTERFACE
3330
THE fOLlOWWG FUNCTIONS ARE PROVIDED:
System BIOS 5-75