On line 74 of the dos.h which comes with djdev201.zip, the structure:

union REGS {
 struct DWORDREGS d
#ifdef _NAIVE_DOS_REGS
 struct WORDREGS x
#else
#if _BORLAND_DOS_REGS
 struct DWORDREGS x
#else
 struct DWORDREGS_W x;
#endif
#endif
 struct WORDREGS w;
 struct BYTEREGS h;
};

needs the line "#if _BORLAND_DOS_REGS" changed to "#ifdef _BORLAND_DOS_REGS"
if "#define _BORLAND_DOS_REGS" in a source file is to work without a parse 
error in dos.h

Change
#if _BORLAND_DOS_REGS
to:
#ifdef _BORLAND_DOS_REGS

Corrected in WIP and will be in v2.03.