Soekris net4526 JP3 (GPIO) pinout

This thing gets indexed by Google, so I'll post this here for the next person who wonders. (I've also updated some random wiki page I wound when googling, and should probably mail the soekris-tech list while I'm at it, but probably won't do that tonight.)

Anyway. The Soekris net4526 single-board computer has on it an 8-bin header connector labelled JP3, which is known to carry five GPIO lines. However, Soekris Engineering hasn't released a manual for the net4526, only for the related net4501, and the only related traffic I found on their mailing list was someone who had figured out some of the pins and was asking for help with the others. (Which is odd, because I thought I'd seen a complete pinout posted there at one point.)

So, since I have a project that might need this feature, I went in and tested myself, and (arranged like they are here, with the JP3 label upright):

1: +3.3V     2: +5V
3: GPIO 7    4: GPIO 8
5: GPIO 11   6: GPIO 21
7: GPIO 22   8: GND

I saw some talk about GPIO numbers in octal or something, so I will add: those are in decimal and zero-indexed, as accepted and reported by NetBSD's gpioctl(8) command. ALso, I have independently confirmed those of the pin assignments noted in the mailing list message I mentioned.

Know further that the pins' input mode has an internal pullup.

The connector I ginned up for the header is also… interesting, and may deserve a post of its own.