if you really need 100% compatibility, just use TP or BP on a DOS machine. BCC2GRX (and the Pascal interface BGI22GRX) were designed to make it easy to port programs, not to allow ill formed programs to work on every platform.

I don't think using a few colors without setting a palette is "ill formed".

PS: You should have found another incompability: On several systems integers are wider than 16 bit causing major trouble ;)

We've already provided a work-around (redefinition in the System unit) for a long time.

Frank