What is it?

Front panel for 8-bit microcomputers that have I2C interfaces.

VHDL code to control an 8-bit FPGA Retro-Computer. This allows the computer to set and increment addresses as well as examine/set memory. Easily expandable for other control and status functions.

The price is for the PCB only. It has a lot of soldering.

The board is available in two versions.

• Rev 1 has some fine pitch parts.
• Rev 2 is entirely through hole parts.

Why did you make it?

I wanted a front panel but with a future twist. Most front panels have rocker switches which are really expensive. But pushbutton switches should be able to do the same thing, right? Yes, they can!

I am using it as the Front Panel for a Z80 retrocomputer project but it could be used with any 8-bit CPU which has an I2C interface (or can emulate one in software).

What makes it special?

It has these features. They may not fit your generic design. Especially since this card has to have an I2C interface.

• I2C interface (Two Wire interface - plus power and ground)
• Occupy I2C addresses either 0x20-0x23 or 0x24-0x27
• Jumper selectable base address
• Jumper Selectable I2C terminators
• I2C daisy-chain connector
• 4 MCP23017 16-bit I2C Port Expanders
• These are fine pitch surface mount parts (Rev 1)
• All through hole parts (Rev 2)
• "Typical" CPU markings (Rev 2)
• 32 Pushbutton Switches
• 32 LEDs