Turbo C++ :: i have a problem when using initgraph ( ) , plx help .

i am success when using initgraph using other graphmodes but IBM8514 .

the graphresult() return GrOk, but
when i draw something , nothing appears.
The flashing underscore _ is displayed.

the getpalettesize() return 256, but
the getmaxcolor() return 16 only.

No problem in other modes, but i want to use IBM8514 because only it has 256 colors.
and i want to know if there any other solutions to use 256 color in turbo c++?

my Eng. is not very good.