8x8 is well within the 8051's capabilities to drive directly (using the shift register as the column drivers). You simply set up a timer interrupt that is 60Hz x #rows = 480Hz.

At 480Hz you shift out 8 bits into the shift register. You also switch the anode driver to the next row. This can be done in less than 100uS at 12Mhz.

100uS * 480Hz = 48000uS. This leaves 962000uS out of each second to do other things.