Apple II+ with VidHD: not working

[tomcw]

Total Replay's VidHD/SHR support works fine on a //e, but I'm experiencing issues on a II+...
(I've just added AppleWin support for VidHD/SHR at 1.30.7.0.)

Repro:

• Select Apple II+ model, and insert VidHD card into slot 3.
• Type "LOD" (for Lode Runner) then SPACE.

NB. Running under emulation: AppleWin 1.30.7.0

Results vary depending on the TR build, but all crash in some way...
(Recommended to run under AppleWin's debugger, with brk all on - to trap on BRK and invalid opcodes.)

Total Replay 4.01

• breaks with invalid opcode $FF at $313

revision 05 / serial number 20210219 (an image that 4am uploaded to Slack on 2021-11-21)

• "Stop reason: HDD DMA to I/O memory of ROM $C000"
• ...because HDD is trying to read a block to $BEF8, which attempts to write to [$BEF8..$C0F7], ie. the $C0 page causes the trap.

revision 05 / serial number 20210219 (an image that 4am uploaded to Slack on 2021-12-18)

• BRK at $2CA

[a2-4am]

SHRSingle saves a pointer to the filename it wants to load, then it calls BlankSHR to clear the SHR screen by writing zeroes to $2000-$9FFF/aux. Because auxiliary memory doesn't really exist outside the VidHD, those writes actually go to $2000-$9FFF/main, which clobbers gSearchStore at $6000/main, which is where the filename pointer is pointing to. Hilarity does not ensue.