back2root:ibm-pc-ms-dos:interrupts:int_13:int_13_08
INT 0x13 - 0x08 - Get Current Drive Parameters (XT & newer)
Request/Call:
reg | value | descr |
AH | 0x08 | |
DL | var | Drive number (0=A, 1=2nd floppy, 0x80=drive 0, 0x81=drive 1) |
| 0x_ | |
Return:
reg | descr |
CF | 0 if successful
1 if error |
AH | status (see INT 13,01) |
BL | CMOS drive type
01 - 51/4: 360K
02 - 51/4: 1.2Mb
03 - 31/2: 720K
04 - 31/2: 1.44Mb |
CH | cylinders (0-1023 dec. see below) |
CL | sectors per track (see below) |
DH | number of sides (0 based) |
DL | number of drives attached |
ES:DI | pointer to 11 byte Disk Base Table (DBT) |
the track/cylinder number is a 10 bit value taken from the 2 high order bits of CL and the 8 bits in CH (low order 8 bits of track)
many good programming references indicate this function is only available on the AT, PS/2 and later systems, but all hard disk systems since the XT have this function available
only the disk number is checked for validity
bit | descr |
0-5 | sector number |
6-7 | high order 2 bits of track/cylinder |
8-15 | low order 8 bits of track/cyl number |
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back2root/ibm-pc-ms-dos/interrupts/int_13/int_13_08.txt · Dernière modification : 2024/03/03 22:11 de frater