74189 IC 64-bit RAM tri-state

The DM7599/DM8599 is a fully decoded 64-bit RAM orga­ nized as 16 4-bit words. The memory is
addressed by ap­ plying a binary number to the four address inputs. After addressing,
information may be either written into or read from the memory. To write, both the memory
enable and the write enable inputs must be in the logical “O” state. Informa­ tion applied to the
four write inputs will then be written into the addressed location. TQ read information from the
mem­ ory the memory enable input must be in the logical “O” state and the write enable input in
the logical “1” state. Informa­ tion will be read as the complement of what was written into the
memory. When the memory enable input is in the logical “1” state, the outputs will go to the
high-impedance state. This allows up to 128 memories to be connected to a com­