wp34s emulator - prgm constant split one digit per line

[Paul Dale]

(12-28-2017 08:34 PM)Dieter Wrote:  A program line that contains a number like -1,234567890123456 E-199, let alone a 34-digit value in double precision mode, would require a substantial number of bytes which can vary with the value itself. Implementing this is not trivial. Maybe Pauli can say more about the details.

The opcodes were designed for the digit per step quite deliberately. Switching to a number per step would have complicated things. It would be possible to leave the encoding as a digit per step and to parse consecutive steps and display a number -- this would make back stepping tricky and we'd also have to store the mode settings used for entry somewhere. Is the number a real or an integer (the same key strokes work fine in both modes currently)? If the latter what sign mode and word size? How to deal with numbers that don't fit on the display anymore? A lot was sidestepped by the current design.

The better way would be to store the assembled value including type information as a program step. The 34S simply isn't setup for this -- it cannot distinguish between integers, reals and strings due to lack of space. The 43S design does include this information and I expect this would be the path to follow.


Pauli