View Map Beyond the raw numbers, what made the 22-805 unique for its time was the range of advanced features packed into a single device:
button to switch from auto-ranging to manual mode. To return to auto-ranging, hold the button for approximately two seconds. Function Selection
The Radio Shack 22-805 uses a Metex 14 protocol , a common command interface that modern software supports. It communicates at a very slow 600 baud with a data format of 7 data bits, no parity, and 2 stop bits (7N2). To connect the meter’s DB-9 serial port to your modern PC, you will need a USB-to-Serial (RS-232) adapter.
Not everything goes as planned, and the manual includes a troubleshooting section to help users identify and possibly fix common issues.