View mb81c4256a-70pftn datasheet:

MB81C4256A-70PFTN (1/2) IL08 ********** C-MOS 1M-BIT DYNAMIC RAM - TOP VIEW - OE 1 24 A8 CAS 2 23 A7 DQ3 3 22 A6 DQ4 4 21 A5 5 20 A4 GND (+5V) DQ1 8 VCC 17 DQ2 9 16 A3 WE 10 15 A2 RAS 11 14 A1 12 NC 13 A0 MB81C4256A-70PFTN (2/2) A0-8 ; ADDRESS INPUT 13 CAS ; COLUMN ADDRESS STROBE A0 14 DQ1-4 ; DATA INPUTS/OUTPUTS A1 15 8 OE ; OUTPUT ENABLE A2 DQ1 16 9 RAS ; ROW ADDRESS STROBE A3 DQ2 20 3 WE ; WRITE ENABLE A4 DQ3 21 4 A5 DQ4 22 A6 23 A7 24 A8 2 11 1 10 SUBSTRATE BIAS 11 GEN. RAS CLOCK GEN. No1 2 WRITE 10 CAS CLOCK CLOCK WE GEN. No2 GEN. MODE CONTROL DATA INPUT BUFFER ADDRESS COLUMN 13-16, BUFFER DECODER 20-24 3, 4, 8, 9 SENSE AMP. A0-A8 DQ1-DQ4 I/O GATE PRE- DECODER DATA OUTPUT 1,048,576-BIT BUFFER MEMORY RE