A2DVI: Apple II Digital Video Card

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2024-09-28 17:30:02

Video cards for the Apple II based on the PICO microcontroller are popular for a while now. They are cheap, consume very little power, and fit on a simple Apple II slot card. And they connect Apple IIs to modern displays. However, digital displays have conquered the world: their analog predecessors long since became retro devices themselves. Nowadays even analog VGA inputs are becoming rare. Which leads to the question: couldn't we make a PICO-based graphics card for the Apple II with a digital output instead? Use HDMI to replace the VGA connector? No more analog signal conversion required?

A few months ago Ralle Palaveev contacted me. He had the idea to make a PCB prototype, combining the PICO-based "Apple II Analog VGA" design with an DVI/HDMI output. He sent me a board, asking if I wanted to look into creating the firmware...

The card connects the DVI's 8 differential signals to I/O pins of the PICO controller. DVI uses four channels, consisting of two differential signal pairs each: three channels for RGB data and one for a clock signal.