HP41.org

Excerpt of attached desription:

The modifications in detail
V10C/X differs in three ways from an original HP10C. The changes are —

• USER mode
  The additional functions are callable in USER mode. While the HP10C has no USER mode its display comprises this annunciator. When in GRAD mode GRD (f-shift 6) will toggle it.
• More memory
  Not influenced by the program size there are allways 16 data register available but only 10 are directly accessible at any time. The six "inaccessible" registers can be swapped with the statistics registers R0..R5. It may be used as primary and secondary data set – or ad lib, it's up to you. To do P<>S hit X≤Y (f-shift /) in USER mode.
• Normal Distribution
  How to use Q and Q-1 is described with examples in HP-32E Owner's Handbook, subsection Normal Distribution. To run Q hit →RAD (f-shift -) in USER mode, to run Q-1 hit →DEG (f-shift +) in USER mode.

Notes:
- Q-1 of HP32E has a hidden flaw, it computes an initial guess for the root finder but doesn't use it for unknown reasons. This mistake is ironed out by one..two more iterations. V10C/X copies precisely HP32E's Q-1 algorithm, this bug inclusively.
- The additional functions are not programmable. Any attempt to enter them in a program will result in the original function code of the corresponding key.
- More memory does not enable longer programs. GTO in 10C programs use line numbers as target, GTO > 79 are filtered at entry. To change that is not worth the drudgery me think.

Edit: removed attachments, for updates see following append.

This is a bugfix update

• fixed a bug in one root finder used in Q-1 function of HP32E
• fixed changing key captions
• fixed description (there are four, not only three modifications of the 10C)

Edit: removed attachments, for updates see following append.

This is an enhancement update

• Menu item "bug fixed Q-1" enables to toggle on the fly between fixed Q-1 and original f/w