Oki 3321, 3320 specifications If WR, Rom, Ram

CN1

OCS	80C51		P1
	RST		P2			Driver
					TD	Receiver
TD	P3		P0	ADR latch
RD					RD
IF WR
				2764
	LS245		DB0 to DB9	ROM
				8 KB
			ADR/data bus	ADR bus
				RAM
				8 KB
						Serial data
+5 VD		±9 V power		+9 V		control line
10 VAC						Bus line
		supply circuit		–9 V
+5 V				+5V		Control line
				0V
			Figure C-2-1 Block Diagram
				C – 3