This is only my guess:

V+ V- (5 volt power source)
P+ P- (Power LED)
T+ T- (Turbo LED)
KEY (Keylock)
GS, S, S (Ground?)
H (???)
L (???)

ISSI 93C46 is an EEPROM chip. Not sure what is under the epoxy resin bubble, but I suspect this LED is programmable. I also suspect the extra wires are

Thanks, it's a start.

Do you think the +5V comes from the 'Reset" switch header connected to the motherboard? Maybe the jumper has something to do with programming it.

Brickpad wrote:

This is only my guess:

H (???)
L (???)

H = High and L = Low (high and low clock speeds)?

Google search finally got me this. This is probably how it is programmed. (Vogon's search doesn't work too well for me)

From this thread MHz display pins

Malvineous wrote:

I've seen some "programmable" MHz displays where you held the reset button down for a few seconds and the number on the display would rapidly increase to 999 and then wrap around to 000 so you could change the number displayed when the turbo was on or off without messing around with jumpers.

I wonder whether that's what the three lots of two pins are for? Power, turbo LED and reset switch?

squareguy wrote:

Thanks, it's a start.

Do you think the +5V comes from the 'Reset" switch header connected to the motherboard? Maybe the jumper has something to do with programming it.

+5V (black and red wires) usually comes from the power supply. Some PSUs had a connector similar to the ones used for the reset switch, powered and HDD LED, etc., that plugged into the LED.

I do not know how to fully setup this thing but I can get it to do what I need.

I have not figured out how it connects turbo to motherboard. I am running another set of wires off of the turbo switch.

V+ V- (5-Volts Power)
S (Unused)
T- T+ (Turbo LED)
+6S (Unused)
P- P+ (Power LED)
KEY (Second set of wires from Reset Switch (this programs it))
H S L (Turbo Button, 3-wire)

I played around with several configurations and the two unused connections and this is what I got to work.