I/O Logic

We can create extra signals for IO by combining the /RD and /WR signals with the /IORQ signals to create /IORD and /IOWR signals. These signals get send down to the IO bus

I/O Logic selection

I/O Bus

All the data lines (D0-D7), the low byte of the Address (A0-A7), The above IO Logic lines (/IORD, /IOWR, /IORQ) a /RESET, as well as power and ground, are all connected to the I/O bus. There are currently 2 spare lines on the bus.

I/O Bus connector