… status flags. All three systems now prompt for inserting a system disk.

* video/huc6272.cpp: modernize handler interface

* machine/t10mmc.cpp: avoid a stack overflow if device can't read CD data, allows PC-FX menu to be useable (with CD in ...)

* video/huc6272.cpp: fix m_bg save state registration, add stub logmacro.h, misc cleanups

- Replace address_map_bank_device with memory views
- Add SCSI controller to s550 and w30
- Eliminate deprecated #ifdef in favor of [[maybe_unused]] attributes

Added Coinage, Remote, and Personal A settings DIP Switches.
Added internal remote credits switch.

- Added a set of service inputs that allow the game to enter the attract.
- Added Coins and remote inputs.
- Fixed the bottom of the screen. Now messages are properly displayed.

…dware

bus/nubus/nubus_image.cpp: Fixed failure to allocate memory for the
image (regressed in b8c3388).

bus/nes/karastudio.cpp, bus/nes/sunsoft_dcs.cpp: Fixed stack smash when
loading loose software.

Addressed some Lua engine fallout from running things in coroutines:
* Don't crash accessing dead Lua thread state from callbacks.
* Allow returning values via yielding functions.
* Don't run address space tap and layout view callbacks in coroutines to
  save overhead.
* Better logging of errors from callbacks.

* implement network ram and fzrom

* implement program transfer interrupts
* suppress duplicate selection command completion
* terminate transfer command on phase mismatch
* implement message in/out ATN/ACK logic
* track interrupt output state
* minor logging improvements

Hooked up the memory card write enable/disable and register select
lines, and corrected the address range where memory card access is
enabled.

Card addressing still isn't quite right - the card bank register isn't
hooked up.  Neo Geo CD consoles also haven't been updated.

Also, more of the same mechanical cleanup of copy/pasted comments,
const, and variable scope.

… PLDs. [Porchy, The PLD Archive, Brian Troha, The Dumping Union]

- funworld/supercrd.cpp: tweaked XOR tables a bit for fruitstr

…cases)

… implemented, couldn't find a driver which cared. Hopefully the regression testing will find some.

* emu/devfind.h: Allow range-based for loops on memory share finders.
* emu/emucore.h: Choose correct emu_fatalerror constructor when format
  string is an rvalue.
* osborne/osborne1.cpp: Allocate main RAM as a flat share, and use a
  view to switch in atttribute RAM.
* Reduced scope of some variables and edited some copy/pasted comments.

-----------------------------
Manx TT Superbike - DX [Brian Troha, The Dumping Union]

------------------
Agent Super Bond (Super Cobra conversion, not encrypted) [Darran Allen]

Enough to get data from the initial bootloader to the serial console.