HP 12C - 12c Platinum -- VAT amount, NET, GROSS

[Dr_Who2]

I really appreciate the given thoughts and observations. Thank you all for the feedback, hints and advice.

I learned, that not every HP-12C variant is the same regarding what is when saved into the stack.
The TVM memory seems to remain untouched on both devices.
Meanwhile, I can see at least three reliable methods, that work on either of the devices:

1. The one given by BruceH through a short program (see below),
2. the one by Khalevipoeg through another short program with the results saved in the x and Y stack [remeber to use the [R scroll key].
3. the one by Gamo utilizing the given TVM keys and utilizing [RCL] key.

@2old2rndr:
Indeed, interesting difference. Since I needed the VAT amount, your calculator does not provide that through TVM by pressing the [+] at the end, while my HP-12CP does.
For other calculations, it might be more useful to not have the TVM values written into the stack, while doing TVM calculations at the same time.

@BruceH
I tried that little program. Works fine on both devices.
However, and this is no big issue, but regarding this statement

"Repeat with the next amount until done."

The second time you give the amount (inkl. VAT) and press R/S, it will not start right away.
One has to press R/S on my devices an additional time first, to start the programed calculation.
After that, it works as described.
I tried putting [g] [GTO] [00] at the end of that little program at no avail.
Still needs an extra [R/S] to start, when the second, third, etc.. value is given.
I am not sure why that is.
Ultimately, it does work though and spares repetitive entry of the VAT % value.

@Gamo
Thank you for reminding about [RCL] while doing TVM calculations. Since I am new to this, I payed no attention to this key. This method works on both calculators and gives the VAT amount.
When I gave [FV] first and press [PV], I get the net value [excluding VAT].
However, right after, pressing [RCL] [FV] [+], gives the VAT amount.
There was no need to use [RCL] FV [RCL] PV [+] to get the result, as [RCL] "first given value" is enough, to get the VAT amount.
Maybe, this is what you meant, as you indicated about both calculations.

Again, thank you all for support.