DRAM 256k x 8

Cross-Reference

BRAND	TAG	NUMBER	PIN COUNT	OUTPUT	MARKINGS
Samsung	KM	41464			KM64257A KM64257AL KM64257B KM64258B KM64259B KM64260B

Dynamic Random-Access Memory 256K x 8

Size

bit	Byte (unpadded)	Hex
2Mb	256KB	200000hex

Pinout

SOJ40 - TSOP40
         +---\/---+
     Vss | 1    40| Vss
      SC | 2    39| SDQ7
    SDQ0 | 3    38| SDQ6
    SDQ1 | 4    37| SDQ5
    SDQ2 | 5    36| SDQ4
    SDQ3 | 6    35| *SE
 *DT/*OE | 7    34| W7/DQ7
  W0/DQ0 | 8    33| W6/DQ6
  W1/DQ1 | 9    32| W5/DQ5
  W2/DQ2 |10    31| W4/DQ4
  W3/DQ3 |11    30| Vss
 *WB/*WE |12    29| DSF
     Vss |13    28| NC
    *RAS |14    27| *CAS
      A8 |15    26| QSF
      A7 |16    25| A0
      A6 |17    24| A1
      A5 |18    23| A2
      A4 |19    22| A3
     Vcc |20    21| Vss
         +--------+

ZIP40
          ^
   Vss  1 |
          |  2 W4/DQ4
W5/DQ5  3 |
          |  4 W6/DQ6
W7/DQ7  5 |
          |  6 *SE
  SDQ5  7 |
          |  8 SDQ4
  SDQ7  9 |
          | 10 SDQ6
   Vss 11 |
          | 12 Vcc
    SC 13 |
          | 14 SDQ0
   DQ1 15 |
          | 16 SDQ2
   DQ3 17 |
          | 18 *DT/*OE
W0/DQ0 19 |
          | 20 W1/DQ1
W2/DQ2 21 |
          | 22 W3/DQ3
   Vss 23 |
          | 24 *WB/*WE
  *RAS 25 |
          | 26 A8
    A7 27 |
          | 28 A6
    A5 29 |
          | 30 A4
    A3 31 |
          | 32 Vcc
    A2 33 |
          | 34 A1
    A0 35 |
          | 36 QSF
   GND 37 |
          | 38 *CAS
    NC 39 |
          | 40 DSF
          -

External links

DRAM page on wikipedia

Files

• 

  KM428C256 Datasheet