Working Condition. Printed test page with it. RS232 Connection. According to the print out it says USB connectivity. It may be behind the back plug in the back but I couldn't get it out. Comes with power wire. There is Tacobell receipt paper I put in it to test it out.

Test can be performed by holding the feed button and turning on the power. Hold the feed for 10 seconds with power on before releasing it.

According to the printout (Technical Specs)

Interface Type: USB or Serial

Serial Interface

Baud Rate: 9600

Data Bit: 8 bits

Parity: None

Handshaking: DTR/DSV

Buffer Size: 4k Bytes