Is there a way to use the HANDLE and DWORD variable types with the Cx51 & 8051? And if so, do I need to use a certain '#include'? Thanks!
These are not 'C' standard types. Therefore, you need to look at the available data types in the C51 Manual and create your own suitable typedefs or #defines as required. The same would apply for any other compiler. Note that "DWORD" is a poor choice for a type name, as it gives no direct indication of its size or whether or not it is signed. Hence I always prefer things like: U8 - unsigned, 8 bits; S16 - signed, 16 bits; etc
Ah, you're trying to use the MS Windows API on an 8051, aren't you: http://www.keil.com/forum/docs/thread7590.asp That's a complete non-starter!