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norfavrell wrote:Hey.
Let's say that we want to read 5 segments. The first of those segments is on absolute track 1 and absolute segment 16. Would int 13h automatically increment register CH to read 2 segments from track 1 and 3 from track 2? Or do i need to take care of that in the code?
Also what would happen if segments were overlapping to second head?

Thanks in advance,
Bart

Ralf Brown's Interrupt List wrote: INT 13 - DISK - READ SECTOR(S) INTO MEMORY
AH = 02h
AL = number of sectors to read (must be nonzero)
CH = low eight bits of cylinder number
CL = sector number 1-63 (bits 0-5)
high two bits of cylinder (bits 6-7, hard disk only)
DH = head number
DL = drive number (bit 7 set for hard disk)
ES:BX -> data buffer
Return: CF set on error
if AH = 11h (corrected ECC error), AL = burst length
CF clear if successful
AH = status (see #00234)
AL = number of sectors transferred (only valid if CF set for some
BIOSes)
Notes: errors on a floppy may be due to the motor failing to spin up quickly
enough; the read should be retried at least three times, resetting
the disk with AH=00h between attempts
most BIOSes support "multitrack" reads, where the value in AL
exceeds the number of sectors remaining on the track, in which
case any additional sectors are read beginning at sector 1 on
the following head in the same cylinder; the MSDOS CONFIG.SYS command
MULTITRACK (or the Novell DOS DEBLOCK=) can be used to force DOS to
split disk accesses which would wrap across a track boundary into two
separate calls