Start replacing special device macros with additional constructors,
starting with ISA, INTELLEC 4 and RS-232 buses.
Allow an object finder to take on the target of another object finder.
(For a combination of the previous two things in action, see either the
INTELLEC 4 driver, or the Apple 2 PC Exporter card. Also check out
looping over a device finder array to instantiate devices in some
places. Lots of things no longer need to pass tags around.)
Start supplying default clocks for things that have a standard clock or
have all clocks internal.
Eliminate the separate DEV versions of the DEVCB_ macros. Previously,
the plain versions were a shortcut for DEVICE_SELF as the target. You
can now supply a string tag (relative to current device being
configured), an object finder (takes on the base and relative tag), or
a reference to a device/interface (only do this if you know the device
won't be replaced out from under it, but that's a safe assumption for
your subdevices). In almost all cases, you can get the effect you want
by supplying *this as the target.
Eliminate sound and CPU versions of macros. They serve no useful
purpose, provide no extra checks, make error messages longer, add
indirection, and mislead newbies into thinking there's a difference.
Remove a lot of now-unnecessary ":" prefixes binding things relative to
machine root.
Clean up some miscellaneous rot.
Examples of new functionality in use in (some more subtle than others):
* src/mame/drivers/intellec4.cpp
* src/mame/drivers/tranz330.cpp
* src/mame/drivers/osboren1.cpp
* src/mame/drivers/zorba.cpp
* src/mame/devices/smioc.cpp
* src/devices/bus/a2bus/pc_xporter.cpp
* src/devices/bus/isa/isa.h
* src/devices/bus/isa/isa.h
* src/devices/bus/intellec4/intellec4.h
This allows for the much more natural "import another map and patch
it" structure, or "cover a whole region then punch holes in it". Our
previous first-entry-wins rule was always a surprise to newcomers, and
oldcomers too.
Beware, the device context does not follow in MCFG_FRAGMENT_ADD
anymore due to the prototype change. So creating a device then
configuring through a fragment doesn't work as-is. The simplest
solution is just to add a MCFG_DEVICE_MODIFY at the start of the
fragment with the correct tag.
Use standard uint64_t, uint32_t, uint16_t or uint8_t instead of UINT64, UINT32, UINT16 or UINT8
also use standard int64_t, int32_t, int16_t or int8_t instead of INT64, INT32, INT16 or INT8
