This type of display is a pain to use directly with a limited memory microcontroller such as an 89xx52 type part. The displays of this type are normally meant to be driven from a continuous real time video stream such as may come from a video source or a self contained video controller. Many such displays can indeed be used with a VGA output...but there may need to be some connector wiring and signal conditioning to perform to get it to work properly.

The VGA use typically means that the display then ends up being tethered to a PC implementation instead of a microcontroller,

The only really feasible way to use these display types with a microcontroller is to build up some type of controller in a CPLD/FPGA and then attach some memory chip as the video buffer and provide a low level interface to an 8052 microcontroller. (Note some FPGAs may even have enough RAM right on board without having to even add a separate RAM chip(s). Somebody here on this site has actually done some work like this. Search and you should find it.

Michael Karas