Serial Keypad
 
 
Product Description: 
    This unit is a serial-interface keypad that can be used with either the 49-451, 2-zone alarm system, or the 49-485, 8-zone alarm system. 
Designed at: 
    Tandy Electronics Design 
Sold at: 
    Radio Shack as 49-452
Credits: 
    Hardware - Doug Deeds 
    Software - Dusty Nidey
    Mechanical - Morris Humphreys