DECUS C can not compile ANSI C, it does not support function prototypes,
nor local variables in blocks. The OTS cannot be built as a supervisor
mode library.

I've created a full build file ([5,1]MAKE.CMD) and a batch file to
build DECUS C unattended ([5,1]DOMAKE.CMD). Since I only have
RSX-11M+ to play with, this is what I've verified. I've tried to
get all source code up to date, no matter which OS, but no build files
except the RSX ones have been touched.

Things that can be done to improve DECUS C:

o	Check DECUS C on RT-11.
o	Check DECUS C on RSTS/E.
o	Check DECUS C on PRO.

o	Fix CX library
		The CX library isn't really much RSX-11M+ aware yet.
		Currently, M+ and MicroRSX are treated equally, but
		there might be a few misses around. It should be checked
		out properly.

o	Add an argument pointer.
		This means the compiler must be changed a lot.
		One register must be reserved for AP. When the parameters
		are setup for a call, the AP must be set as well.
		Inside a function, the parameter variables must be
		referenced in relation to AP, and not R5.
		All library functions must be rewritten to use AP instead
		of R5.

		This is not a difficult job, but it's quote a lot of work.

o	Create a memory resident library, and a supervisor mode library.
		Once the argument pointer work is done, this is an
		obvious extension. It have some good benifits, the biggest
		being that if the C OTS is in supervisor mode, you can
		write larger programs.

o	Change the stack layout. This also comes after the AP stuff.
		The #pragma ast code currently stores R0 and R1 in static
		variables, which must be preserved if ASTs are allowed
		when in an AST. If the AP code is in, then R0/R1 can be
		saved on the stack. ACRET$ must be rewritten some in this
		case.

o	Make build files for RT-11 and RSTS/E.
		This would be really nice to have, in the same style as the
		RSX build files, perhaps?

o	Function prototyping.
		This is rather tricky. The compiler parsing of function
		headers must be rewritten, and also, function calls should
		then match parameter types.