HP97 The journey begins

[teenix]

(02-04-2020 04:16 PM)Helix Wrote:  

(01-31-2020 12:19 AM)Archilog Wrote:  Very good news, Tony, many thanks for this major improvement.

How does it work exactly? It's not described in the help file.

Apologies, I'll put it in today.

When you access the menu, the first item is [CALC StAtE].
Selecting this brings up choices to save or recall the state data.

The idea is to save the data then turn off the calculator, although you can continue on and have that state saved for later use. For example if you are about to try and modify a complex program and break it, you could recall the state that has the original program and start again.

When the calculator is switched on again, and the data recalled, the calculator will resume in that state.

The PRGM/RUN/(timer) switch is tested for the same position on state recall. If there has been a change then the state data is invalid and a message is displayed. Just put the switch in the same position and recall again.

The state function can be done in a different hardware/software setup and leave the PIC processor in low power mode when it senses main power is removed. However, the HP on/off switch removes all power to the CPU board, and a separate power wire will need to be connected from the battery to the CPU board which gets a bit messy and I decided not to go that path.


Edit: The help file has been amended and uploaded.


cheers

Tony