Pioneer SCSI-2 - Manual (Page 16)

CD-ROM SCSI-2 COMMAND REFERENCE MANUAL VERSION 3.1 (OB-U0077C)
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1.3 SCSI Protocol
The SCSI Protocol outlined in this section applies only to SCSI bus models. It does not support
ATA bus models.
1.3.1 Command Link/Control Field
The Control Field inside the Command Block is defined as:
Bit 7 6 5 4 3 2 1 0
Vendor Unique Reserved Flag Link
The Command Link function is not supported by the DRM/DR-U Series. Set Flag and
Link bits to “0” (FALSE).
Set the RelAdr (Relative Address) bit, bit 0 of byte 1, inside the Command Block to
“0” (FALSE).
1.3.2 Disconnect/Reselect
Selection time-out period is 250 ms.
If the initiator does not respond to reselection within the time-out period, the drive will
release the bus for a minimum of 200 ms. The drive will then repeat the
arbitration/reselection sequence until the initiator responds, issues BUS DEVICE
RESET, or until the SCSI bus is reset. During a reselection retry, the drive will return
BUSY to selection requests from any initiator.
During execution of audio commands, if the disconnect/reselect function is selected,
the drive disconnects from the initiator before execution a SEEK or other operation
that requires head movement. When the selected address is located, the drive reselects
the initiator and begins audio playback. The time needed for the reselection procedure
is dependent upon the status of the SCSI bus. Audio playback may begin before the
reselection is complete. Refer to Appendix A for more information.