saundby

The keyboard is what's known as a membrane keyboard. Basically, the keyboard is still switches connecting two wires together. The wires are in the form of a matrix, laid out logically as columns and rows. So if a wire from column A touches a wire in row 3, the keyboard controller detects that, coverts it to the correct keycode, then sends it to the PC. You can try tracing the wires back from the membranes to where they connect to the controller (often a small PCB, possibly with a regular chip on it, possibly with a chip under a blob of epoxy on it) and figure out the matrix. Here's an example of a matrix diagram: http://www.sharpmz.org/mz-700/kbmatrix.htm You can also just figure out which connections are the columns and which are the rows (it doesn't matter for your purposes which is which, just figuring out that one set is for one group and the other are part of the other group.) Then you can plug it into a PC, open an editor, start shorting connections and figure out the character map that way. For example, let's say you've divided the connections into two groups, plus determined which lines carry the modifier keys like Alt, Ctrl, and Shift. Mark the connections somehow if they're not already marked. Then, say, connect one end of a wire to what you've decided to call contact row1, and touch the other end to what you've called connection column1, then column2, column3, etc until you have noted all the keys on row1. Then go to row2 and do the same thing. Then, when you want to wire up SAS, you look at your chart and see that T is, say, row5 to column3. Bingo. Wire your switch between those two points and you're good.