View through the big
vent (hole) on the back, showing part of the
circuit board. Also shows the attached 9-volt
battery. What does the battery do? Steve
says: The battery mounted on the back is the
power supply for the serial port RS-232 connector
on back. This serial port was added to allow
connection to a modem when I first bought the
computer. Ohio Scientific did not fully populate
the motherboard to allow use of the serial port.
So I added the necessary components to the
motherboard and connected the battery to supply
power to the serial power connection.