Load/Unload specific status:

Following a successful LOAD command, CHECK CONDITION is posted to all initiators other than the initiator of the LOAD command. The sense key is set to UNIT ATTENTION, with additional sense of 2800h (not ready to ready transition). There is an exception to this: if a load occurs when the tape is already loaded, no UNIT ATTENTION sense is generated.

Once UNIT ATTENTION is cleared, unsolicited positional sense is set. The sense key will be NO SENSE with additional sense of 0004h (BOT detected).

If an unformatted tape is inserted, the drive loads it and it behaves as if it is a blank tape.

If a cartridge with no Cartridge Memory or a failed Cartridge Memory is loaded, CHECK CONDITION is returned with a sense key of MEDIUM ERROR, with additional sense of 5200h (cartridge fault).

Loading a cartridge

The drive loads a tape automatically when it is inserted, without any host interaction. If the load is successful, media access commands are permissible (see the Media Access check).

If the tape is already loaded when a Load request is received, the tape is positioned at the beginning of the tape (as though a REWIND had been sent). Unlike a “full” load, UNIT ATTENTION with additional sense of 2800h (not ready to ready transition) is not generated for other hosts.

If the tape is in the process of being loaded when the Load request is received, the drive will wait for the load to complete and, assuming the load was successful, take one of the following actions:

•If the Load was issued by the current host (that is, a previous immediate-reported load) and completed successfully, GOOD status is reported. No further action is taken.

•If the Load was issued by some other host (or was an autoload) and completed successfully, CHECK CONDITION is reported, with a sense key of UNIT ATTENTION and additional sense of 2800h (not ready to ready transition).

•If the Load was issued by the current host and failed, CHECK CONDITION is reported, since a deferred error condition will exist for the current host.

•If the Load was issued by some other host and failed, the load will be re-attempted on behalf of the current host.

Unloading a cartridge

If an unload is requested and there is a tape present in the drive (either loaded, loading or unloading):

1.Any buffered data is written to tape.

2.The tape is rewound to the physical BOM (beginning of media).

3.If medium removal is prevented, CHECK CONDITION is reported with a sense key of ILLEGAL REQUEST and additional sense of 5302h (medium removal prevented).

Commands

LOAD/UNLOAD 1Bh 51