Spice Low Power

[PANAMATIK]

The First Spice Low Power board is running!

HP-34 SLP and original having the same display output.

For my testing and writing the SPICE LP software I couldnt use wobbly contacts, therefore I soldered the SLP and LED display to the flex board preliminary. All components are working; Real Time Clock, Flash memory, LED display and keyboard are doing their job, the software is complete, no hardware issues. I'm very happy.

I do recommend to solder the display anyway when you use the Spice LP. The solderless contacts are responsible for missing digits and LED segments of many of these calculators, which sometimes could be temporarily repaired when you hit the calculator on the table. It is easy to solder the display to the flex board, but solder only for one second to avoid melting the plastic. Also tin the display contacts before, they do often have an oxide layer.

Soldered SPICE LED display

The problem, which remains is the mechanical contact to the 40 pads. Unfortunately the pads of the flex board are outside of the circuit border, or do only touch the edges. There is no way for solderless inserting the SLP. I will try to solder the board for the first time in the next days. Second issue is that you have to remove some of the plastic from the board cover, which is no problem, but I will try to improve this with the next layout.

Fitting into the board space.

All SPICE models are implemented HP-31, HP-32, HP-33C, HP-34C, HP-37, HP-38C, but it is impossible to include also the classic or woodstock models, because the SPICE models have only 10 digits, instead of 12 (Woodstock) and 15 (Classic). But who wants to run a HP-25 on a HP-34C hardware anyway?

I received only two prototype boards. Fortunately both are OK. Now I have to test soldering the circuit to the flexboard pads and placing it inside the calculator case, then I will continue with an improved layout.

Is there any standard HP-34 program collection, which I could insert to the SLP? Or do you have an idea how to get good solderless contacts?

Bernhard