Hi Walter,
hrrrmmm...sorry. Techno speak mode wasn't cancelled, where it should have been....
ISP: In-System-Programmer
An ISP is a tool, to low-level program an uC (microcontroller), which already is soldered
into a circuit.
Other terminus technicus: In-circuit programmer.
HVP: High voltage programmer, where "high voltage" is every voltage above 5V/3.3V (depends
on the system) and NOT something to make sparks and buzzing arcs from.
I dont know, whether are used outside the ATMEL-world.
These are tools which allows to "reset" a uC.
ATMEL chips (ATmega...) have "fuses" which one can "burn" programmatically to prevent others
from reprogramming or reading the flash. "Burning" those fuses can done with a normal, not-HV-programmer
...also accidentically...and the poor DIY girl/guy has one desktop decoration more and one chip to play/program
with less. In those cases a HVP becomes handy: It totally nullify (write zeroes/FFs) to everything, which can be
programmed of such a chip. This way, the flash contents get lost, but the hardware is saved.
Here are some examples:
https://en.wikipedia.org/wiki/In-system_programming
https://mightyohm.com/blog/2008/09/ardu ... rogrammer/
By the way: In case of a calculator of this price tag (not meaning, that the DM42 is not worth each single EURO it costs!!!
I LOVE this gem! -- but about 200 EURO are 200 EURO) I think "learning by experience" is little too harsh -- especially for
those, who do this experience -- especially when checking for USB-power (the routine is already in the firmware) and quiting
the firmware update process if only the battery is there, seems to me a not too complicated task for a magician like David, whose
magic was one of the main reasons, why we all got these wonderful piece of technique.
Only my two cents...your currency may vary...
Cheers
Meino
DM 42 - SN: 00373, Firmware release v.:3.22. / DMCP 3.24. as compiled by SwissMicros