DRAM 64KB RAM ( Data RAM, address range from $0000 to $FFFF )

LSI DRAM 4164C-3, 4864P-2, or MB8264-15 65,536 word x 1-bit dynamic random access memory
Circuit diagram and motherboard mark: 7H, 7J, 8H, 8J, 9H, 9J, AH, AJ
MZ-700 SHARP Service Manual info:

Download data sheet of TEXAS INSTRUMENTS SMJ4164 ( PDF, 485 Kb )

Download data sheet of HITACHI HM4864 ( PDF, 310 Kb )

View and download the circut diagram.

View and download the memory map.

Please send me the datasheets of the 4164C-3 and MB8264-15 if you have these, thanks.