8-bit input/output port expansion card with a pass-through connector and a RESET button.
It allows easy connection of MUMIO standard devices, safely isolated from the ZX Spectrum bus and without needing to know its internal structure.
Each card can be assigned an I/O port address from 0–255 using an 8-position switch. Multiple cards can be connected in series, each set to a different I/O port number.
The output port has 8 bits/pins, on which the latched state of the last value sent to the port is maintained. The state of the output port is indicated by LEDs. The input port is not latched. Both ports (input and output) are isolated from each other.
