Différences

Ci-dessous, les différences entre deux révisions de la page.

@@ Ligne 1: / Ligne 1: @@
+====== Int 13h - Disks - WIP ======
+<nspages -h1 -simpleList -exclude:start -TextPages="">
+=== Most disk BIOS calls use the following parameter scheme: ===
+^ reg  ^ description ^
+|AH    | function request number|
+|AL    | number of sectors  (1-128 dec.)|
+|CH    | cylinder number  (0-1023 dec.)|
+|CL    | sector number	(1-17 dec.)|
+|DH    | head number  (0-15 dec.)|
+|DL    | drive number (0=A:, 1=2nd floppy, 80h=drive 0, 81h=drive 1)|
+|DL    | drive number (0=A:, 1=2nd floppy, 80h=C:, 81h=D:)\\ Note that some programming references use (0-3) as the drive number which represents diskettes only.|
+|ES:BX | address of user buffer|
+=== and return with: ===
+| CF | 0 if successful \\ 1 if error |
+| AH | status of operation  (see [[back2root:ibm-pc-ms-dos:interrupts:int_13:int_13_01|INT 13,01]])|
+<WRAP round box>
+  * INT 13 diskette read functions should be retried at least 3 times to assure the disk motor has time to spin up to speed
+  * physical sector numbers can be converted to and from DOS sector numbers with the following formulas:
+</WRAP>
+<WRAP center round tip 75%>
+<m 15>DosSector = (sector - 1) + (head * SectorsPerTrack) + (track * SectorsPerTrack * NumHeads)</m>
+</WRAP>
+<WRAP center round tip 75%>
+<m 15>PhysicalSector = 1 + (DosSector  MOD  SectorsPerTrack)</m>
+</WRAP>
+<WRAP center round tip 75%>
+<m 15>PhysicalHead = (DosSector / SectorsPerTrack)  MOD  NumHeads</m>
+</WRAP>
+<WRAP center round tip 75%>
+<m 15>PhysicalTrack = DosSector / (SectorsPerTrack * NumHeads)</m>
+</WRAP>
+[[back2root:ibm-pc-ms-dos:interrupts:|Back]]

Nox-Rhea WiKi

Outils pour utilisateurs

Outils du site

Différences

Outils de la page