not hard to find, google for the wavs, get a yak-bak or make your own, then rig it up to play the sound when you press the buttons. if you want it truly well done, you'll need to program a seperate one for each switch though :S
I'm also thinking that the best way to do this would be via a PIC chip or a STAMP. There would be a signal circuit providing a digital output at a certain frequency. There would then be 8 momentary switches connected in parallel between the digital signal and the microcontroller. It would be programmed such that the separate inputs in the chip would have to be "engaged" in the right order before the eight switch was pressed. Then and only then would the microprocessor send a signal to the motherboard to power on the computer. There are probably other ways to do this using LCRs or relays. A microprocessor allows you more control since you can more easily control LEDs in the different symbols. Although if you want LEDs in more than the 7 specified glyphs, you're going to need more switches. If this is all hard wired to the computer, 5V would be perfect to power whatever logic you choose to use. I'm not too familair with LCRs but I remember that there are simple alarm circuits where once an LCR is latched on, it remains on until power is disrupted. Perhaps 7 LCRs can keep LEDs lit up and the 8th engages the computer while it unlatches the LCRs.
