It works!!!

I finally have successfully worked out the problems with communicating with the Dragon's Lair hardware. It now seems to be working perfectly (phew!!).

I did two things:
1) the AVR datasheet has specific instructions on how to switch between input and output modes that I was not exactly following so I fixed that
2) I enabled the AVR's internal pull-up resistors when in input mode which meant when dragon's lair stayed in input mode during the command strobe, I would receive a FF command.

My log file for your curiosity/enjoyment:


listener: VLDP-HW: LDP Status: Stopped
listener: Controller is not using our current settings, so we are pushing down new ones.
listener: VLDP-HW: Settings applied
listener: Controller is using our current settings (yay!)
listener: VLDP-HW: LDP Status: Stopped
listener: VLDP-HW: LDP Status: Stopped
listener: VLDP-HW: LDP Status: Stopped
listener: VLDP-HW: LDP Status: Stopped
listener: VLDP-HW: <- cd
listener: VLDP-HW: -> 7c
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> fc
listener: VLDP-HW: <- 3f
listener: VLDP-HW: -> 7c
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> fc
listener: VLDP-HW: <- 3f
listener: VLDP-HW: -> 7c
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> fc
listener: VLDP-HW: <- f
listener: VLDP-HW: -> 7c
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> fc
listener: VLDP-HW: <- 5f
listener: VLDP-HW: -> 7c
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> fc
listener: VLDP-HW: <- 1f
listener: VLDP-HW: -> 7c
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> fc
listener: VLDP-HW: <- f7
listener: VLDP-HW: Search to frame 197
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: LDP Status: Searching
listener: VLDP-HW: -> d0
listener: VLDP-HW: LDP Status: Paused
listener: VLDP-HW: LDP Status: Paused
listener: VLDP-HW: LDP Status: Paused
listener: VLDP-HW: <- cd
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 3f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 3f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 4f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 3f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 6f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- f7
listener: VLDP-HW: Search to frame 306
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: LDP Status: Paused
listener: VLDP-HW: LDP Status: Paused
listener: VLDP-HW: LDP Status: Paused
listener: VLDP-HW: <- cd
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 3f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 3f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 4f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 8f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- 4f
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- f7
listener: VLDP-HW: Search to frame 323
listener: VLDP-HW: -> 50
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> d0
listener: VLDP-HW: <- fd
listener: VLDP-HW: Play
listener: VLDP-HW: -> 64
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> e4
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: LDP Status: Playing
listener: VLDP-HW: <- cd
listener: VLDP-HW: -> 64
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> e4
listener: VLDP-HW: <- 3f
listener: VLDP-HW: -> 64
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> e4
listener: VLDP-HW: <- 3f
listener: VLDP-HW: -> 64
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> e4
listener: VLDP-HW: <- f
listener: VLDP-HW: -> 64
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> e4
listener: VLDP-HW: <- 5f
listener: VLDP-HW: -> 64
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> e4
listener: VLDP-HW: <- 1f
listener: VLDP-HW: -> 64
listener: VLDP-HW: <- ff
listener: VLDP-HW: -> e4
listener: VLDP-HW: <- f7
listener: VLDP-HW: Search to frame 197