SYM-1 Keyboard

Following is info about keyboard and 6 digit 7 segment display expansion prototype board that was used with mini SYM board to run monitor program from the keypad. It is similar in layout to original SYM-1 board. Keys are made up of pcb push button switches, that have 2 square caps on them. One cap clips over the switch then another CLEAR plastic cap clips over the top again. By placing appropriate size bit of paper with text on it, ANY keyboard key indicator can be made up. (see picture)

The only issue with these switches is that they had too much horizontal (rotational) play and hence keys do not look all lined up. Placing the keys close would eliminate some of that, however mounting the switches on the pcb requires some distance between adjoining pins - so it is not possible to bring the rows close together.