This short description from

  Alberto Vignani <a.vignani@crf.it> Sat Jul  8 23:27:58 2000

only in order to not loose valuable information.

I _really_ expect some more worked out documentation  --Hans, 2000/07/09

What's new:

1) ZeroBaseTime is now in cycles instead of us. This simplifies things in
   the cpuemu even if his required moving some #include <timer.h>.
2) SIGTIME has been un-macroed to its standard value of SIGALRM, and another
   time signal (currently SIGPROF) has been introduced for future use in the
   cpuemu.
3) TRACE_DPMI is currently enabled only if cpuemu is compiled in; use the
   -D{n}t option to enable it, where if n>1 registers and disassembly are
   written to the logfile. It traces the "regular", not the emulated, DPMI,
   and doesn't trace vm86 code, only PM.
4) FP coprocessor error full decoding.
5) Support for BOUND (int5) exception.
6) Moved some structs and defines from port.c to port.h, for use by the
   cpuemu.
7) The cpuemu itself. It is now called SIM86X.
   The user interface has not changed from previous version; you always
   have to use ecpuon/ecpuoff to enable/disable it,
   and -D{n}e for debug logging.
   The makefile has some optimization options:
	OPTIMIZE_BACK_JUMPS
	  tries to resolve short branches without breaking a compiled
	  sequence. Quite safe.
	OPTIMIZE_COMMON_SEQ
	  tries to compact push..push, pop..pop, movs etc. to generate
	  shorter code
	OPTIMIZE_FW_JUMPS
	  tries to resolve short forward branches without breaking a
	  compiled sequence,
	  but it's a bit dangerous with self-modifying code and it's
	  enabled only for DPMI (PM) code.
	USE_BOUND
	  someone proposed to use it for emulating PM features,
	  I implemented it for CS: accesses, just for fun.
	SINGLESTEP
	  as the name says.
8) I used a lot of double-slash C++ style comments.

What works under cpuemu: DOS (at least IBM DOS 7.0), Norton Commander,
ndiags, djgpp (at least the latest version 2.0.3), some CPU test programs,
tasm, text-mode demos, sourcer.
What doesn't yet work: doom and many graphic demos.
Not yet tested: Turbo C, Win3.1.

Alberto
