See the ChangeLog file looking for lines taged with the word FIXME.

	COREFILE.C: The implementation of corefile.c (defined by
	corefile.h) isn't the best.  It is intended to be functionaly
	correct rather than fast.  One option being considered
	is to add a data cache to reduce the overhead of the most
	common case of data read/writes.

	HTAB (page) code for OEA model untested.  Some of the vm code
	instructions unimplemented.

	Lacks PowerOpen (a.k.a. XCOFF a.k.a. AIX) and NT startups.  The
	PowerOpen worked until I added the ELF one.

	Missing VEA system calls.

	Missing or commented out instructions.

	64bit target untested.

	64bit host broken.  For instance use of scanf "%x", &long long.

	Event code for pending events from within signal handlers not
	finished/tested.

	Better and more devices.

	PORTABILITY (Notes taken from Michael Meissner): Heavy use of the ##
	operator - fix using the clasic X/**/Y hack; Use of the signed
	keyword.  In particular, signed char has no analogue in classic C
	(though most implementations of classic C use signed chars); Use of
	long long which restricts the target compiler to be GCC.