MODE SELECT This flag can be used to switch the drive between normal operation and CD-ROM emulation mode:
•If this bit is set to its existing value, there is no change.
•If this bit is changed from 0 to 1, the drive will enter CD-emulation mode. It will change its Inquiry and Mode data appropriately and cache the first 250 KB of the CD image off tape. CD-ROM support commands will be enabled. This transition is primarily present to support automated functional testing.If the bit is changed from 1 to 0, the drive leaves CD-ROM emulation mode and reverts to normal tape drive mode.
•If this bit is changed from 1 to 0, the drive will leave CD-emulation mode. The Inquiry and Mode data will revert to that for a tape drive and CD-ROM command support will stop. The tape will be reloaded and the logical position will be BOP. Backup applications can use this transition to switch to a normal mode of operation for file system recovery off tape. Note that operating systems that pre-load class drivers at boot might not be prepared to talk to the erstwhile CD- ROM drive
