Nortel Millennium Phone: Keypad

I have decoded the rows and colums of the front panel buttons.

• 1: Column
• 2: Column
• 3: Column
• 4: Column
• 5: Column
• 7: Row
• 8: Column
• 9: Row
• 10: Hook Up
• 11: Row
• 12: Hook Common
• 13: Row
• 14: Hook Down
• 15: Unknown
• 16: Unknown
• 17: Unknown
• 18: Unknown
• 19: External Speaker
• 20: External Speaker