ahaa.. ok i got what you mean so you having FBB Graphic card. Ok lets change the syntax:
Try this
Code:
#/usr/sbin/ffbconfig -res 1152x900x76 -depth 8
try change the value m64config to ffbconfig or fbbconfig, should be one of them depends on the type of card that you use. Give a try. Post back if that solution doesnt help.