Z80 Second level board (Board "B")
Standard Z80 microprocessor.
27128 (16K x 8) EPROM memory.
6264 (8K x 8) RAM memory.
1 INPUT PORT (74HC244).
1 OUTPUT PORT (74LHC374).
1 Programmable I/O port (Z80 PIO).
Clock Frequency: 2.5 MHz.
64 pin Expansion Bus.
Single Power Supply (+5V).
