Have you ever wanted to connect your PiDP-11 to physical hardware? Then look no further!

The PiDP-11 I/O Expander adds 16 GPIO pins with interrupt capability to Oscarv's excellent PiDP-11 project. These pins can be used to interface with components located in the built-in prototyping area or with external hardware. If 16 pins aren't enough, multiple boards can be chained together to add up to 128 GPIO pins to a single system.

This kit contains everything needed to expand the I/O capabilities of your PiDP-11:

• I/O Expander PCB (Assembled & Tested)
• Jumper Wires
• Pin Headers
• Double-Sided Tape

For installation instructions, see the documentation on Hackaday.

Details

The heart of the I/O Expander is a Microchip MCP23016, which is similar in function to the popular MCP23017 with the added benefit of TTL compatibility to support both 3V3 and 5V logic levels. The I/O Expander provides GPIO access to 16 pins over I2C (up to 400kHz), which can be independently configured and controlled by software. Interrupts are fully supported and routed to GPIO 19 on the Raspberry Pi.

Up to 8 I/O Expander boards may be connected in series to increase the total number of GPIO pins to 128. Rework may be needed to support multiple boards (eg. adjusting pull-up resistor values) depending on installation method and overall bus capacitance. Additional pin headers must be also be fitted and shunted to configure I2C addresses to avoid bus conflicts.

For more details, see the latest release on GitHub.