Values for disk operation status:

| 00h | successful completion |
| 01h | invalid function in AH or invalid parameter |
| 02h | address mark not found |
| 03h | disk write-protected |
| 04h | sector not found/read error |
| 05h | reset failed (hard disk) |
| 05h | data did not verify correctly (TI Professional PC) |
| 06h | disk changed (floppy) |
| 07h | drive parameter activity failed (hard disk) |
| 08h | DMA overrun |
| 09h | data boundary error (attempted DMA across 64K boundary or >80h sectors) |
| 0Ah | bad sector detected (hard disk) |
| 0Bh | bad track detected (hard disk) |
| 0Ch | unsupported track or invalid media |
| 0Dh | invalid number of sectors on format (PS/2 hard disk) |
| 0Eh | control data address mark detected (hard disk) |
| 0Fh | DMA arbitration level out of range (hard disk) |
| 10h | uncorrectable CRC or ECC error on read |
| 11h | data ECC corrected (hard disk) |
| 20h | controller failure |
| 31h | no media in drive (IBM/MS INT 13 extensions) |
| 32h | incorrect drive type stored in CMOS (Compaq) |
| 40h | seek failed |
| 80h | timeout (not ready) |
| AAh | drive not ready (hard disk) |
| B0h | volume not locked in drive (INT 13 extensions) |
| B1h | volume locked in drive (INT 13 extensions) |
| B2h | volume not removable (INT 13 extensions) |
| B3h | volume in use (INT 13 extensions) |
| B4h | lock count exceeded (INT 13 extensions) |
| B5h | valid eject request failed (INT 13 extensions) |
| B6h | volume present but read protected (INT 13 extensions) |
| BBh | undefined error (hard disk) |
| CCh | write fault (hard disk) |
| E0h | status register error (hard disk) |
| FFh | sense operation failed (hard disk) |