There are several other IOP16 demos that use the Land Boards Front Panel I2C card. The Hackaday page for the Front Panel is here.

The code controls the four MCP23016 parts. These are 16-bit I2C parallel I/O expanders. The advantage using the Land Boards Front panel card is it only uses 2 FPGA I/O pins to read 32 pushbuttons and write 32 LEDs. The IOP16 runs the Front Panel I2C interface. The GitHub for the Front Panel example is here.

There are three examples so far.

• FrontPanel01 - Controls the second port of a Dual Port SRAM simulating control of a VHDL Retro Computer
• FrontPanel01B - Controls the second port of a Dual Port SRAM simulating control of a VHDL Retro Computer
• FrontPanel01_Test_LoopBack - Loopback toggle of pushbutton to LEDs.

There's also an example for Multicomp which controls an M6800 CPU running MIKBUG. This is a fully functional Front Panel example.