According to his own disclosures, he has a fear of dogs
https://web.archive.org/web/20120119135147if_/https://secure...
the keyboard and trackpad are internally PS/2.
Interesting that the PC influence is still there, although I'm pretty sure a MIPS doesn't have them on port 60h/64h, or indeed any I/O ports. I remember having a similar moment of surprise when I played around with an ARM VM and discovered it had a "VGA-compatible" GPU emulating an old ISA-class chip.