QPI for the HP-42S


This is just a short note to tell that I have just uploaded the latest version of QPI for the HP-42S at the following URL:


Best regards,
Erik Ehrling (Sweden)


Where did you get the font you used for the program listing?

Regards, Juergen


Hi Juergen!

The listing is just made up of a series of screen-shots from Emu42 (so in a sense the underlying font is the real HP-42S font, although it is not made using a font per se), however if anyone could recommend a good program to construct a font from bitmaps it would not be much work to convert it into a real font.

Best regards!


Look in here for some nice fonts produced by Luiz:



Lines 381 and 383 should not be there; they cannot be correct. 


fills the stack

Cheers, Werner


Hi Werner!

Certainly the lines should be there! The lines 2-12 at the start of the program stores the contents of the stack (and all registers). The corresponding lines 376-391 at the end of the program restores the stack (and all registers). This way program encapsulation is achieved on the HP-42S! Further, this allows you to run QPI in the middle of a calculation and then continue the calculation after QPI has run!

Best regards,
Erik Ehrling (Sweden)


No, Werner is right, I've noticed this too. The lines 381 and 383 are too much. Consider: If you do


you will restore the saved T register contents directly to T. But if you now execute


the stack is lifted and the contents of T are lost. Instead you should just do


as Werner suggests, and the entire stack will be restored.

Cheers, Victor


Oh yes! The lines are redundant (even though the program works perfectly with the lines in place as well...). Thanks!


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