Normally, communication between the LV-ROM player and the BBC Master AIV is via SCSI, each of these elements of the Domesday System having their own SCSI interface. There are two different forms of SCSI communication. The first form is to communicate with the LV-ROM player as a mass storage device, using all the usual SCSI calls to read data from the volume in the drive.
The second form is by sending commands known as function codes, or F-Codes, to the player which control the playback operations of the VP415. In fact, the method of sending F-Codes to the player via SCSI is identical to the method for requesting the player to perform any other SCSI operation: there is a special vendor-specific SCSI command code which the player supports which deals with F-codes.
Despite this, I think it's worth making a distinction between SCSI operations which access the disc as a hard drive of sorts, and SCSI operations which control the VP415 as a laserdisc player. This set shows the basics of transmitting and receiving F-codes between the player and the BBC using SCSI, and I hope you will click on the picture links above to learn more.
Click here to go back to using VP415 Player under Computer Control