LARGE arrays on IBM PC with 640k RAM?

[Nicholas Yue]

Hi,
Does anyone know of a way to implement large arrays

        unsigned char *raster;

        raster = (unsigned char *)malloc(640*480*3);

the above certainly won't work because my PC only has 640k RAM
but K&R suggested using lseek() and treat large files as array.
I tried it but unsuccessfully, does anyone has any suggestion?
Or some sources that will work? Preferably, the solution(s) do
not need hardware upgrade or purchase of other software! I
have TURBO C.

Thanks In Advance

nicholas at woylie.cs.uwa.oz.au