IBM PC CONVERTIBLE Technical Reference page 164

05S6
05S6
B4 10
05SS ES 0000 E
05SB SA FS
05SD FE C4
05SF E8 0000
0592 SA E7
0594 Bl 03
0596
2A CA
059S
74 06
059A
DO El
059C DO El
059E 03 ES
05AO
05AO 24 OF
05A2 C3
05A3
********************************************
GELDRLCONFIG
GET DRIVE INFORMATION SUBROUTINE
INPUT CONDITIONS: DL = DRIVE NUMBER 0-3
OUTPUT CONDITIONS: AL (LOW NI BBLE CONTAINS DRIVE TYPE)
CARRY FLAG SET I F DRIVE
#
OUT OF RANGE
REGISTERS MODIFIED: AX,BX,CX
********************************************
GELDRLCONFIG PROC NEAR
MOV
CALL
MOV
INC
CALL
MOV
MOV
SUB
JZ
SHL
SHL
SHR
GELDRVOI :
AH, RTCDSKLCON
GELRTCREG
BH,AL
AH
GELRTCREG
AH, BH
CL,3
CL,DL
GELDRVOI
CL,1
CL,1
AX,CL
AND AL,OFH
RET
GELDRY..-CONFIG ENDP
GET DRIVE INFORMATION
DRIVE 0,1 IN BH
DRIVE 2,3 IN AL
DRIVE 0-3 INFO IN AX (NIBBLES)
SET SHIFT COUNT
SUBTRACT DRIVE NUMBER
MULTIPLY BY 4 (BITS/ DRIVE)
SHI FT TO GET DRIVE INFO
SAVE ONLY LOW NIBBLE
Bootstrap Loader Interrupt Hex 19
(SYS-BOOT)
05A3
05A3
FC
05A4
B8 ---- R
05A7
SE
os
05A9 ES 0000
05AC ES 0000
05AF 75 4C
05Bl
05Bl FB
05B2 2B CO
05B4 SE CO
;--- INT 19H --------------------------------------------
BOOT STRAP LOADER
TRACK 0, SECTOR 1 IS READ INTO THE
BOOT LOCATION (SEGMENT 0, OFFSET 7COO)
AND CONTROL IS TRANSFERRED THERE.
IF THERE IS A HARDWARE ERROR CONTROL IS
TRANSFERRED TO THE ROM BASIC ENTRY POINT.
ASSUME CS: ROMCODE, OS: DATA, ES: ABSO
SYS_BOOT PROC NEAR
CLD ; SET FORWARD 01 RECTI ON
FORCE DCL SUPPORT FOR BOOTSTRAP
MOV AX, DATA
MOV DS,AX
CALL
DSP_INIT
CLEAR THE SCREEN
CALL
RES_ERR_CHK
CHECK AND DISPLAY RESUME ERRORS
JNZ
HL3 JUMP I F ANY RESUME ERRORS
RETRLBOOT:
STI ENABLE INTERRUPTS
SUB AX,AX ESTABLI SH ADDRESS I NG
MOV ES,AX
RESET THE DSKT PARAMETER TABLE VECTOR
ROM BIOS 2-139