IBM XT 5160 Technical Reference page 271

LOC OB.JECT
LINE
SOURCE (B I OS FOR THE I BM PER SONAL COMPUTER XT) 1 1 /08/82
; ----- TURN DR I VE 0 MOTOR ON
SETUP PRINTER AND RS232 BASE ADDRESSES IF DEVICE ATTACHED
.----------------------------------------------------------------
F9:
·
------------------------------------------------------------------------
; A CHECKSUM IS DONE FOR THE 4 ROS MODULES CONTAINING BASIC CODE
SET BEG I NN I NG ADDRESS
SET BX=OOOO
GET 1ST WORD FROM MODULE
PO I NT TO NEXT 2K ADDRESS
RECAL I BRATE DISKETTE
GO TO ERR SUBROUT I NE I F ERR
SELECT TRACK 34
SEEK TO TRACK 34
OK, TURN MOTOR OFF
DSK ERR:
GET-ADDR OF MSG
GO PR I NT ERROR MSG
GET ADDR OF FDC CARD
TURN MOTOR ON, EN DMA / I NT
WR I TE FDC CONTROL REG
DRO OFF:
TURN DR I VE 0 MOTOR OFF
FDC CTL ADDRESS
MOTOR WAIT:
WA I T FOR 1 SECOND
MOTOR_WA I T 1 :
SELECT DR I VE 0
SELECT TRACK 1
AT F6000 YET?
GO CHECK ANOTHER ADD. I F NOT
GO CHECK BAS I C ROM
BUS SETTL I NG
= TO ID WORD?
PROCEED TO NEXT ROM I F NOT
GO CHECK OUT MODULE
CHECK FOR END OF ROM SPACE
AL,OCH
DX,03F2H
DX,AL
DX,OC800H
DX,0080H
DX,OF600H
ROM SCAN 1
BASE_ROM=CHK
DS,DX
BX,BX
AX, [BX]
BX
BX
AX,OAA55H
NEXT ROM
ROM CHECK
ARE=WE_DONE
MOV DX,03F2H
MOV AL,ICH
OUT DX,AL
SUB CX,CX
LOOP Fl1
LOOP F12
XOR DX,DX
MOV CH,I
MOV SEEK_STATUS ,DL
CALL SEEK
.JC F13
MOV
CH,34
CALL SEEK
.JNC F14
MOV S I ,OFFSET F3
CALL E_MSG
MOV
MOV
OUT
POP OS
MOV
AL, BYTE PTR EQU I P_FLAG
DISKETTE PRESENT?
AND
AL,O lH
NO - BYPASS DISKETTE TEST
.JZ F15
FlO:
01 SK_TEST:
IN AL, INTAO 1
AND AL,OBFH
ENABLE 0 I SKETTE INTERRUPTS
OUT INTA01,AL
MOV
AH,O
RESET NEC FDC
MOV
DL,AH
SET FOR DR I VE 0
INT
13H
VERIFY STATUS AFTER RESET
TEST AH,OFFH
STATUS OK?
.JNZ F13
NO - FDC F A I LED
; ----- TURN DR I VE 0 MOTOR OFF
F15:
MOV I NTR_FLAG, OOH
SET STRAY
I NTERRUPT FLAG = 00
MOV SI,OFFSET KB_BUFFER
SETUP KEYBOARD PARAMETERS
MOV BUFFER HEAD, S I
MOV BUFFER=T A I L , S I
MOV
BUFFER_START, S I
ADD S 1,32
; DEF AUL T BUFFER OF 32 BYTES
MOV
BUFFER END, S I
MOV
o
I ,OFFSET PR INT_TIM_OUT ; SET DEF AUL T PR INTER TIMEOUT
PUSH OS
POP ES
MOV AX,1414H
; DEFAUL T=20
STOSW
STOSW
MOV
AX,O 10 1H
; RS232 DEFAULT=O I
STOSW
STOSW
IN
AL,INTAOI
AND
AL,OFCH
; ENABLE T I MER AND KB INTS
OUT
INTA01,AL
E4:
SUB BX,BX
SETUP STARTING ROS ADDR
MOV
DS,DX
CHECK ROS
CALL
ROS_CHECKSUM
.JE
E5 CONTINUE IF OK
CALL
ROM_ERR POST ERROR
E5:
ADD DX,0200H
PO I NT TO NEXT 8K MODULE
DEC AH
ANY MORE TO DO?
.JNZ E4
YES - CONTINUE
.---------------------------------------------------------------
; CHECK FOR OPTI ONAL ROM FROM C8000->F4000 IN 2K BLOCKS
(A VALID MODULE HAS '55AA' IN THE FIRST 2 LOCATIONS,
LENGTH I NO I CATOR (LENGTH /512) I N THE 3D LOCAT I ON AND
TEST/INIT. CODE STARTING IN THE 4TH LOCATION.)
DISKETTE ATTACHMENT TEST
DESCR I PT I ON
CHECK IF IPL DISKETTE DRIVE IS ATTACHED TO SYSTEM. IF
ATTACHED, VER I FY STATUS OF NEC FDC AFTER A RESET. ISSUE
A RECAL AND SEEK CMD TO FDC AND CHECK STATUS. COMPLETE
SYSTEM INITIALIZATION THEN PASS CONTROL TO THE BOOT
LOADER PROGRAM.
F13:
F14:
Fl1 :
F12:
·
---------------------------------------------------------------
ROM SCAN:
- MOV
ROM SCAN 1:
- MOV
SUB
MOV
PUSH
POP
CMP
.JNZ
CALL
.JMP
NEXT ROM:
- ADD
ARE WE DONE:
- - CMP
.JL
.JMP
·
------------------------------------------------------------------------
BASE ROM CHK:
- MOV AH, 4 NO. OF ROS MODULES TO CHECK
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
E591
E591 BOOC
E593 BAF203
E596 EE
E56A BAF203
E56D BO 1C
E56F EE
E570 2BC9
E572
E572 E2FE
E574
E574 E2FE
E576 3302
E578 B501
E5 7 A 88163EOO
E57E E8FC08
E581 7207
E583 B522
E585 E8F508
E588 7307
E58A
E58A BE52EC90
E58E E81814
E551
E551 IF
E552 AO 1000
E555 2401
E557 743E
E559
E559 E421
E55B 24BF
E55D E621
E55F B400
E561 8AD4
E563 CD13
E565 F6C4FF
E568 7520
E597
E597 C6066BOOOO
E59C BE 1EOO
E59F 89361 AOO
E5A3 89361 COO
E5A 7 89368000
E5AB 83C620
E5AE 89368200
E5B2 BF7800
E5B5 IE
E5B6 07
E5B7 B81414
E5BA AB
E5BB AB
E5BC B80 10 1
E5BF AB
E5CO AB
E5Cl E421
E5C3 24FC
E5C5 E621
E541 E8AE13
E544 7403
E546 E88201
E549
E549 81 C20002
E54D FECC
E54F 75EC
E53B
E53B B404
E53D
E53D 2BDB
E53F 8EDA
E518
E518 BAOOC8
E51B
E51B 8EDA
E51D 2BDB
E51F 8B07
E521 53
E522 5B
E523 3D55AA
E526 7506
E528 E82814
E52B EB0590
E52E
E52E 81 C28000
E532
E532 81 FAOOF6
E536 7CE3
E538 EBO 190
5-124
PC-XT System BIOS (11/08/82)