Errors are reported by the BIOS and XBIOS as negative values. The following list contains all known error-messages:
| No. Name | Meaning |
| 0 E_OK | OK. No error has arisen |
| -1 ERROR | Generic error (not specified precisely) |
| -2 EDRVNR | Addressed device/drive not ready |
| -3 EUNCMD | The specified command is unknown |
| -4 E_CRC | Error when reading a sector / CRC error |
| -5 EBADRQ | Bad request / The device cannot execute the command |
| -6 E_SEEK | Drive couldn't reach the specified track |
| -7 EMEDIA | Read error (medium has a wrong boot sector) |
| -8 ESECNF | Sector was not found |
| -9 EPAPER | Printer is not ready / Out of paper |
| -10 EWRITF | Error during a write operation |
| -11 EREADF | Error during a read operation |
| -12 EGENRL | General error |
| -13 EWRPRO | Medium is write-protected |
| -14 E_CHNG | Medium was changed after a write operation |
| -15 EUNDEV | Device is not known to the operating system |
| -16 EBADSF | Bad sectors detected during formatting |
| -17 EOTHER | Another floppy disk must be inserted. This error only appears if Drive B: is accessed without it being connected. In such a case the user is asked to insert a floppy disk into the first drive. |
| -18 EINSERT | MetaDOS error: Insert medium |
| -19 EDVNRSP | MetaDOS error: Device does not reply |
| -128 SNDNOTLOCK | Falcon XBIOS: Sound-system not reserved |
| -129 SNDLOCKED | Falcon XBIOS: Sound-system already reserved |
See also: Error-messages in MagiC GEMDOS error-messages