add extra debugging for DMAgic registers to track down.
try being a bit stricter about what happens when reading colour
ram since that seems likely to be a causative factor in all this.
(uart monitor s1f900 5 gives device not found error (CPU state
failure), while sff80100 5 works fine, being the non-shadowed
version of colour ram access).
implement better abstraction for remapping address space,
used only for colour ram access at $01F800 for now.
apply same abstraction of access colour ram to the writing
side of the CPU as has just been introduced on the reading side.
fix synthesis bugs
try implementing F011 sector write operation.
add crude interfaces to microphone, accelerometer and thermometer.
implment PWM audio output.  8-bit resolution, so PWM rate is
cpu clock / 256. at 32MHz = 125KHz sample rate.
latch digital audio output level more sensibly.
implement PDM decoder for microphone. 7-bit left and right
audio now available via registers. like most of the other recent
commits, this is all yet to be tested.
add missing nets.
fix typos and bugs with new peripherals.
fix write-protect flag when using F011 emulation registers to write.
writes will now fail to write-protected disk images.
fix f011 EQ flag (was never set)
annotate write sector routine in C65 ROM.
fix name of aclSCLK -> aclSCK.
make PS2 keyboard scan codes available.
begin adding support for RESTORE key triggering NMI on short press
and RESET on long press (>0.5 seconds).
fix reset and nmi from restore key plumbing, and allow switches
14 and 15 to mask NMI and RESET respectively for debugging.
fix keyboard mapping to match keyrah v2 with switch in lower
position.