I opened up my keyboard and traced out the circuits again today. I HOPE this is right, I haven't double checked it. Everything in caps is as it appears on the keyboard. Names that are too long are abbreviated and shown in lower case. A list of the abbreviations and their meanings is also shown below. pin 21 20 19 18 17 16 15 14 2 nu kl K1 K2 K3 K4 ^ da 3 1 2 3 4 5 6 7 8 4 Q W E R T Y U I 5 A S D F G H J K 6 sb Z X C V B N M 13 nu nu -l da -CHAR REP -> <- 12 nu RESET bs nu = - 0 9 11 nu nu nu sca ) ( P O 10 nu nu nu nu el ' ; L 9 nu nu nu RUN PAUSE ? > < Abbreviations: nu = not used da = down arrow (up and down arrow are used to recall previous commands and for editing)(I just noticed that I have this listed twice so there's probably an error there somewhere). k1 = Key Label el = End Line (this is what HP uses for carriage return/Enter) sb = space bar bs = Back Space -l = -Line (erases the entire line) sca = Scratch (erases all memory, just variables, etc depoending on what argument you give it) Notes: The K keys are programable function keys. K5 through K8 are K1 through K4 shifted. You can assign programs or functions to these keys and use the Control input lines to trigger the program or function. The -Char key erases one character at a time. the REP key toggles between the insert and replace modes. There are a few more keys that don't fit into a matrix. Here's a list of them and the two pins that they connect to: Both SHIFT keys are tied together in parallel and connct to pins 18 and 7. There is a 8 Ohm .2Watt speaker inside. It connects to pins 25 and 7. CNTL key connects to pins 23 and 7. CAPS LOCK key connects to pins 24 and 7. I'll try to photograph the keyboard and post the picture tomorrow so that you can see what the layout and key legends and shifted legends are.