As of 0.1.7 the GPIO feature is advertised as in development and involves the memory region 0x5f80-0x5fff (128 bytes). In the web player, this memory region can be accessed by external JavaScript by defining the window global pico8_gpio = new Array(128). Does the RaspPi build do anything with actual RaspPi GPIO pins yet? Does the bundled PocketCHIP version do anything with GPIO? (I get my PocketCHIP on Monday.)

I wrote a two-way memory mapper to watch this region and set values as I messed with stuff and didn't get very far. There are some necessary features, such as setting pin modes, that are either missing or encoded in an undocumented way in the memory region. I don't see any activity in either direction if I set pin modes outside of Pico-8 either. I verified my set-up with regular GPIO test code. I also took a quick guess based on the strings tool that Pico-8 was using a GPIO driver with C functions such as gpio_write(), and I tried setting debugger breakpoints and saw no hits, but I'm not confident I did that correctly so that's not conclusive. (Reverse engineering newb. :) )

Any official word? Has anyone had success reverse engineering in this area? Any reverse engineering tips or suggestions?

I read somewhere that GPIO features for RPi will be released in 0.1.9 (here or in the #pico8 channel).