How do you know what revision level (or date of production) of the calculator you have? Are there any notable differences in the calculator over time? The calculator I recently obtained had an Owner's Manual Edition 7, Jan 1992, and does not appear to mention any hardware or firmware revision level differences.
Quote:
* Press ON & LOG together to enter the debugger.
* Press the decimal point.
It doesn't work for me:
I get three vertical lines and a beep until I press the decimal point. Then the display reads "SPD 1048352".
I can quit with ON & SQRT.
Oops, my bad. I shouldn't have just copied those instuctions from that web page.
Here's the improved version:
* Press ON & LOG together, then press left-arrow, to enter the debugger.
* Press the decimal point.
* Now a character on the left and a digit on the right will be displayed briefly: This is the ROM version number.
* Press ON & the square root button together to quit the debugger.
That's better!
Mine is C7 (serial # 3312S09630)
Hi,
only for your information:
The revision is C only.
The digit to the right is the latest warmstart event code.
Raymond
Interesting. Thanks. I have revision C. Is there any significance to that?
You (Thomas Okken) mentioned you got this key stroke sequence from a web site. Where? Are there any other odd keystrokes that can make the calculator do interesting things? In playing around I ran into some screen, RAM, ROM, URAM, and keyboard tests.
Hi,
much information can be found on:
http://www.hp42s.com/
Especially for the test mode including
the memory scanner look here:
http://www.hpcalc.org/details.php?id=1755
The latter is a page which has a link to a zip archive,
which has all needed info on the test mode,
and much more.
HTH
Raymond
As far as I know there are three Rom versions of the HP-42S.
- Version A with the flat display
- Version B also with the flat display bu much rarer
- Version C with the embedded display (common version)
Matthias