This applies to the following Melco legacy machine models: EMT1, EMT10, EMT10T, EMT10T-F1 and EMT10/4T
Turn the machine OFF and remove disk from the disk drive.
Turn machine ON.
Count to 8 slowly.
Hold down these 3 keys on the machine simultaneously: ALT + UP ARROW + DOWN ARROW
Listen for a beep. Then release the 3 keys. (it's ok if there's no beep, release the keys after about 30 seconds)
The display should show: [Machine Model]____Bx (B0, B1, B3 or B5)
If it doesn’t display the correct machine model and revision (eg. "EMT10TF1__B5), use the up or down arrow until you see the correct machine model and then hit Enter.
Hit Enter again. It should then go through some tests and prompt you to "Insert Boot Disk."
Insert the disk and hit enter. It should then boot up.
Or...If the machine is networked to a computer it will say download requested and power up.