Tuning The Hardware Of Your Wp 34S - HP RPN SCIENTIFIC WP 34S Owner's Manual

The six pad serial port of the calculator is located
under the battery door, below the RESET hole. For
those who want to connect to it directly, here is the
pinout. It is identical for both business calculator
models, the HP-20b and the HP-30b. The pitch is
2 mm . The picture is of the printed circuit board un-
covered, the RESET button is north of the six pads.
There is an additional JTAG connector at the
southern end of the main board (not accessible
from outside), partially covered by a tag here.

Tuning the Hardware of Your WP 34S

As mentioned at the very beginning of this manual, there are three optional hardware
modifications you may benefit from. Please read the respective descriptions and decide
what you are interested in. Then read the complete instructions for these cases before
actually starting the modification – this is to prevent you will end with your WP 34S half
usable. These are the opportunities:
1. Create an accurate real-time clock by adding a quartz crystal and two capacitors on
the main board of your WP 34S.
This modification requires some fine soldering skills due to the size of the
capacitors – they are SMD components and significantly smaller than a grain of rice!
Besides fixing these two properly at the correct location, this modification is an easy
job. See Alexander Oestert's very nice instruction file at
wp34s.svn.sourceforge.net/viewvc/wp34s/doc/How_to_install_crystal_and_IR_diode.pdf
2. Establish an IR line for printing on an HP-82240A/B by adding an IR diode and a
resistor to the package after modification 1. Electrically, this part is significantly
easier than the job above. There is some additional mechanical work: drilling a little
hole in the plastic case, requiring a slow hand and a correct drilling bit. The
complete job is also described in the file mentioned above.
3. You may combine the setup of both the IR line to the printer and an USB
connection for data exchange and power supply at once by installing a little custom
board Harald Pott developed
Here you will need some sol-
dering skills as well (not as
fine as for modification 1
above, but
mechanical skills are required,
too, since an extra gap in the
calculator case for the micro
81
Harald developed more than this custom board for your WP 34S. We chose what he calls PCB version 2.
We rate it most helpful since it combines the features mentioned above and is easy to install as described
below. See also http://wp34s.svn.sourceforge.net/viewvc/wp34s/doc/WP_34S_USB_installation.pdf
information about his other boards and Harald's address.
WP 34S Owner's Manual
81
(it was already mentioned in
close). And
Edition 3.1
Appendix A).
Page 192 of 211
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for