HP Classic upgrade kit - Multi Emulator (updated list of emulated models)

[teenix]

(03-04-2018 12:25 AM)rprosperi Wrote:  How about this:

For those models that originally had Continuous Memory, the emulator should behave the same way the original machine did (i.e. retain those portions of memory retained in the original machines), and other models of course would not. When powering-on, the "C" models would have the saved information loaded.

In addition, the "C" models would also have the "SC" feature that lets you save the same information to a file, which could be restored via some other specific manually-invoked command, thus letting you save a particular configuration (programs, registers, etc.) and easily restore it at some later date, but meanwhile use the normal "C" memory retention during power-off/power-on sessions.

So, you get the best of both worlds.

Hi Bob,

The SC feature came about because Harald's controller is powered by the host Classic Series calculator which was never designed for constant memory. When the power is switched off, everything goes off and all memory disappears.

It takes the PIC controller a little over a second to save the required CM information to its internal memory. Harald's controller would need special hardware to detect the switch off and then keep all the circuits running to reliably accomplish the data save before actually powering down, not an easy task.

Therefore the SC feature is a simple way of saving the required memory before switching off the CM models. This data is automatically recovered at power on and therefore mimics the real CM behaviour. The only problem is that you have to remember to save any 'new' memory data before turning it off, otherwise the previously stored data (if available) will be recovered next time it is switched on.

Its brother, the MultiCalc kit doesn't actually turn off. When switched off, it still runs in a special low power mode and memory stays active. However, just like the real calculators , if you remove power the memory will be lost and it will not recover at the next power on.

I'm not really sure that it is required, but to save extra CM files would mean tapping into the external program storage memory and reduce the storage space for programs for the programmable models.

cheers

Tony