If this information is elsewhere in the forum, excuse me! I didn't find it.

In a post about a year ago in the thread Re: HP 30B not in blister pack Katie Wasserman wrote,

Quote:

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....What's the date on the firmware?

To check that:

1) Turn off

2) Press and hold PMT

3) Press ON

4) Press DOWN 4 times

Thanks, Katie

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How interesting! My question is, what other power on key codes are there and what do they do?

Thank you,

Harry

Edited: 1 Oct 2011, 5:47 p.m.

Is there nothing online that lists the HP-30b/20-b self tests? Gee, I thought that Gene would have done that if not HP. At any rate they are:

- Screen Test, press INPUT to start and press to cyle through the 12 different displays

- Keyboard Test, press each key at least once in any order. Once they have all been pressed the test ends.

- Checksum, the number of the left side of the decimal point should equal the number on the right side of the decimal point.

- Battery Test, this is the voltage of the batteries. They are in parallel so it's sort of an average.

- Software Version, date of the firmware.

- Copyright message (also shows the amount of non-volitile RAM used by the firmware, should always be 2048, I think).

- Test System, pressing INPUT will toggle the test system on/off. The test system was used in development but when on will run the calculator somewhat faster and burn through batteries at lightning speed.

- Slow Clock, you can adjust the clock speed a little bit. I forget if this had a noticeable effect.

- Serial, I'm not sure. I think that this allows debugging of the serial interface that's used in the Test System.

Some of the above are guesses, please correct me if you know better.

-Katie

Edited: 1 Oct 2011, 8:20 p.m.

If you look into the sources of the SDK you can learn about the serial and test system stuff.