The Mini 4116 DRAM Tester is a simple and effective way to test the 4116 RAM chips that are often found in old computers and arcade games. It works from a mini USB (not included) connected to 5 volts. This unit will transform the voltage into the required 5, -5 and 12 volts for the unit to operate and will test each address of the RAM. If each address returns no errors the RAM will show as being good. You can also run a stress test which will continue the test indefinitely until it is manually stopped.