IBM XT 5160 Technical Reference page 266

LINE SOURCE (BIOS FOR THE IBM PERSONAL COMPUTER XTl 11/08/82
;----- UNNATURAL ACT FOR ADDRESS COMPATIBILITY
.
------------------------------------------------
EIO:
5-119
READ CRT STATUS PORT
CHECK VIDEO/HORZ LINE
I TS ON - CHECK NEXT LINE
LOOP IF OFF TILL IT GOES ON
READ CRT STATUS PORT
CHECK VIDEO/HORZ LINE
ITS ON - CHECK IF IT GOES OFF
LOOP TILL ON OR TIMEOUT
GO PR I NT ERROR MSG
GET V IDEO SENSE SW INFO
SAVE IT
B/W CARD ATTACHED?
SETUP ADDR OF BW STATUS PORT
YES - GO TEST LI NES
COLOR CARD I S ATTACHED
L1NE_TST:
OFLOOP_ CNT :
SETUP START I NG LOC
NO. OF BLANKS TO 01 SPLAY
WR I TE V IDEO STORAGE
GET V IDEO SENSE SWS (AH)
SAVE IT
ENABLE V IDEO AND SET MODE
VIDEO
WRT BLANKS I N REVERSE V IDEO
GO TEST VIDEO R/W STG
R/W STG FAILURE - BEEP SPK
; SEND INIT TO B/W CARD
01,01
CX,40
STOSW
AX
AX
AH,O
10H
AX,7020H
SHORT E lOA
OE2C3H
NMI_INT
AL,30H
E8
AH
AL,20H
E8
AH,3
AH,AL
AX
AH,AH
10H
AX
AX
BX,OBOOOH
DX,3B8H
CX,2048
AL, I
AH,30H
E9
BH,OB8H
DX,3D8H
CH,20H
AL
AX,DATA WORD[OFFSET EQUIP FLAG] , GET SENSE SWITCH INFO
AX - ;-SAVE IT
AL,30H
DATA WORD[OFFSET EQUIP FLAG] ,AX
AH,AH -
10H
AL,20H
DATA WORD[OFFSET EQUIP FLAG],AX
AH,AH - ; AND INIT COLOR CARD
10H
AX , RECOVER REAL SW I TCH INFO
DATA WORD[OFFSET EQUIP FLAG],AX , RESTORE IT
- - AND CONT I NUE
AL,30H ISOLATE VIDEO SWS
E7 , VIDEO SWS SET TO O?
01 ,OFFSET V IDEO I NT ; SET I NT 10H TO DUMMY
[0
I ] ,OFFSET DUMMY RETURN , RETURN I F NO V IDEO CARD
EI8_' - BYPASS VIDEO TEST
TEST VIDEO:
B/W CARD ATTACHED?
YES - SET MODE FOR B/W CARD
SET COLOR MODE FOR COLOR CD
80X25 MODE SELECTED?
NO - SET MODE FOR 40X25
SET MODE FOR 80X25
SET MODE:
SAVE V IDEO MODE ON STACK
I NIT I AL I ZE TO ALPHANUMER I C MD
CALL VIDEO 10
RESTORE V IDEO SENSE SWS IN AH
RESAVE VALUE
BEG VIDEO RAM ADDR B/W CD
MODE REG FOR B/W
RAM WORD CNT FOR B/ W CD
SET MODE FOR BW CARD
B/W V IDEO CARD ATTACHED?
YES - GO TEST V IDEO STG
BEG V IDEO RAM ADDR COLOR CD
MODE REG FOR COLOR CD
RAM WORD CNT FOR COLOR CD
SET MODE TO 0 FOR COLOR CD
TEST VIDEO STG:
OX, AL , 0 I SABLE V IDEO FOR COLOR CD
DATA WORD[OFFSET RESET FLAG] ,I234H , POD INIT BY KBD RESET?
ES,BX - POINT ES TO VIDEO RAM STG
E 10 YES - SK I P V IDEO RAM TEST
DS,BX POINT OS TO VIDEO RAM STG
OS: NOTH I NG, ES: NOTH I NG
STGTST CNT
E17 -
SUB CX,CX
IN AL,DX
AND AL, AH
JNZ EI4
LOOP E13
JMP SHORT E I 7
SUB CX,CX
IN AL,DX
AND AL,AH
JZ EI6
LOOP E15
MOV AH,8
POP AX
PUSH AX
CMP AH,30H
MOV OX, 03BAH
JE Ell
MOV OX, 03DAH
JMP
ORG
JMP
SUB
MOV
REP
POP
PUSH
MOV
INT
MOV
OUT
CMP
MOV
JE
MOV
ASSUME
CALL
JNE
CMP
JE
INC
CMP
JNE
MOV
XCHG
PUSH
SUB
INT
POP
PUSH
MOV
MOV
MOV
MOV
CMP
JE
MOV
MOV
MOV
DEC
AND
JNZ
MOV
MOV
JMP
PC-XT System BIOS (11/08/82)
MOV
PUSH
MOV
MOV
SUB
INT
MOV
MOV
SUB
INT
POP
MOV
CRT INTERFACE LINES TEST
DESCRIPTION :
SENSE ON/OFF TRANS I TI ON OF THE :
V IDEO ENABLE AND HOR I ZONT AL
SYNC LINES.
SETUP V IDEO DATA ON SCREEN FOR V IDEO
LINE TEST.
DESCR I PT I ON
ENABLE V IDEO SIGNAL AND SET MODE.
01 SPLA Y A HOR I ZONT AL BAR ON SCREEN.
I NIT I ALI ZE AND START CRT CONTROLLER (6845)
TEST V IDEO READ/WR I TE STORAGE.
DESCR I PT I ON
RESET THE V IDEO ENABLE SIGNAL.
SELECT ALPHANUMER I C MODE, 40 • 25, B
&
W.
READ/WRITE DATA PATTERNS TO STG. CHECK STG
ADDRESSAB I L I TY •
ERROR
=
I LONG AND 2 SHORT BEEPS
E15:
E14:
Ell:
E12:
E13:
EIOA:
.-------------------------------------------------------
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E2B3 EBll
E2C3
E2C3 E99915
E25C 2430
E25E 750A
E260 BF4000
E263 C7054BFF
E267 E9AOOO
E26A
E26A 3C30
E26C 7408
E26E FEC4
E270 3C20
E272 7502
E274 B403
E276 86EO
E278 50
E279 2AE4
E27B COlO
E27D 58
E27E 50
E27F BBOOBO
E282 BAB803
E285 B90008
E288 BOO 1
E28A 80FC30
E28D 7409
E28F B7B8
E291 BAD803
E294 B520
E296 FEC8
E298
E298 EE
E299 81 3E7204341 2
E29F 8EC3
E2A 1 7407
E2A3 8EDB
E2A5 E8C703
E2A8 7546
E2CD 58
E2CE 50
E2CF 80FC30
E2D2 BABA03
E2D5 7403
E2D7 BADA03
E2DA
E2DA B408
E2DC
E2DC 2BC9
E2DE
E2DE EC
E2DF 22C4
E2E I 7504
E2E3 E2F9
E2E5 EB09
E2E7
E2E7 2BC9
E2E9
E2E9 EC
E2EA 22C4
E2EC 7411
E2EE E2F9
LOC OBJECT
E2C6
E2C6 2BFF
E2C8 B92800
E2CB F3
E2CC AB
E2AA
E2AA 58
E2AB 50
E2AC B400
E2AE COlO
E2BO B82070
E242
E242 A I 1004
E245 50
E246 B030
E248 A31004
E24B 2AE4
E24D COlO
E24F B020
E251 A31004
E254 2AE4
E256 CD I 0
E258 58
E259 A31004