Tape loading

[Ian Miller.]

Is there a SCSI command that can be sent to a TZ87/8/9 tape drive to load a tape which is physically present but not loaded?

I know that the PACKACK IO function can be used to detect that a tape is present. Does this show a tape is loaded and ready to mount or just that a tape is present?

I will do some experiments with SCSI_INFO to see what can be found.

[Ian Miller.]

Intrigingly when SCSI_INFO says its doing a Start Unit then if a tape is present but not loaded then the tape is loaded!

Now I wonder what IO function code SCSI_INFO is doing when it says its doing start unit.

[Volker Halle]

Ian,

SCSI_INFO is using an IO$_DIAGNOSE QIO to send a START_STOP_UNIT_OPCODE (0x1B) with a couple of additional bytes...

Source listings: [SCSI]SCSI_INFO

Volker.

[Jim_McKinney]

SCSI_INFO uses a $QIO with an IO$_DIAGNOSE function code. For the SCSI start and stop unit operations P1 is a descriptor that points to a command data buffer where the SCSI operation code is x1B, and, P2 is the length of that buffer.

[Ian Miller.]

The results of tests of doing commands similar to

$MCR SYS$ETC:SCSI_INFO MKA400 NL:

to load tapes on various drives

TK50 no
TZ30 yes if the handle is over to the right.
TZ87 yes
TZ88 yes