I picked up an old BTC and a Mitsumi that someone was getting ready to toss the other day. The Mitsumi is kinda lame, inverted rubber domes and a membrane the switches touch on. Nothing super exciting, but the BTC is much more interesting. It's a BTC 5339R and down in the bottom left hand corner is a macro key. I'm actually cleaning the keyboard as I write this, since it was pretty gungy. Haven't had a chance to test this thing out yet since I don't have an adapter and don't particularly want to destroy the cable while attempting to solder the PS/2 end to it.
Back to the point, anyone have an idea of what this thing does exactly? From what I've heard, the 53 Series keyboards are fairly common but I have yet to find documentation on the macro key.
