My VFS Utilities ROM works by responding to a service call &27, at which point it reads the byte in CMOS RAM which I've allocated for storing the configured VP setting, and it then issues a VFS VP command with the number read.

It takes a moment to happen, mainly because there is a slight delay between sending a command to the LV-ROM player via the SCSI interface and the player acting upon it. The trained eye will have noticed that we're stil in overlay mode 3 here.

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