S-COM 7K Version 2 (and
Real-Time Clock Installation Instructions
NOTES: The DS1644 module that
you installed at U4 contains 32K bytes of RAM and a timekeeping circuit. Its internal
lithium battery maintains RAM memory data and continues timekeeping when main
power is lost. The original board-mounted batteries plus U11, U12, and their associated
components, are no longer used.
- You will need a soldering pencil,
solder, two small pieces of bare wire for jumpers, a needle-nosed pliers,
and a small screwdriver or similar tool to extract ICs from sockets.
- Disconnect power from the 7K.
- Remove the push-on jumpers (shunts)
from the headers marked "RTC" and "MEM" and discard them.
- Remove ICs U3, U4, and U5 from
their sockets and discard them.
- Form two jumpers from the bare
wire. One jumper goes from U3, pin 1, to U3, pin 8. The other jumper goes
from U3, pin 5, to U3, pin 6. Push the jumper wires into the socket pins and
solder them in place. (From the component side of the board, count the IC
socket pins counter-clockwise.)
- Carefully push the DS1644 IC into
the socket marked U4. Carefully push the EPROM (a 27C256 with the label marked
V2.0 or later) into the socket marked U5.
- Initialize the controller by performing
a cold start. (Hold the INITIALIZE pushbutton down while applying power, and
continue to hold the button down until the CW message begins.)
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Last Revised: 23 December 2002. Questions or comments regarding this
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