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van2z · (This post was last modified: 12-31-2023 01:04 PM by van2z.)

I've been working on an HP-80 emulator with this ROM.

It mostly works, but I found buggy behavior when I try to use y^x. Here are steps to reproduce:

1. 2 (Or any other number)
2. SAVE↑
3. y^x

Normally, the display turns off, does the calculation, then turns back on.

But it seems there might be a bug here. The display turns back on *during* the calculation. You end up seeing an animation of it "thinking" with various random numbers quickly flashing before it gets the answer.

Can anyone who has an HP-80 please verify for me what you see?

Thank you,
Veniamin

ThomasF · (This post was last modified: 12-31-2023 01:23 PM by ThomasF.)

(12-31-2023 12:44 PM)van2z Wrote: IThe display turns back on *during* the calculation. You end up seeing an animation of it "thinking" with various random numbers quickly flashing before it gets the answer.

Can anyone who has an HP-80 please verify for me what you see.

Yes, this is just normal behavior! Shortly after key release the display flickers during calculation, verified on my HP80.
There are several other calculators that behave the same when you start to emulate next generation of HP calculators ... Wink

Cheers,
Thomas

AndiGer · 12-31-2023, 01:33 PM

Tried on my HP-80 .... display flickers during calculations.

I think this is due to complex financial calculations. Especially if you resolve to i(nterest) as this is calculated as iteration and can last several seconds - the more digits you set in the display the more iterations. This way you see the calculator is still busy ... (Same on HP-81 - the desktop equivalent.)

Remember (I read somewhere) when you do financial calculations on the HP-80/HP-81 you must enter the values from left to right.
E.g. 5 n, 500 PMT, 3000 FV. Then resolve to i what will give 9.13 to 2 decimals.

Andi

teenix · 12-31-2023, 01:36 PM

(12-31-2023 12:44 PM)van2z Wrote: The display turns back on *during* the calculation. You end up seeing an animation of it "thinking" with various random numbers quickly flashing before it gets the answer.

Can anyone who has an HP-80 please verify for me what you see?

Thank you,
Veniamin

HP coders did this so that on long calculations or while a program is running, the user gets feedback showing that the calculator is busy. The code has various points where the display is cycled on and off.

If you like, you can check your emulators against mine at http://www.teenix.org. They are pretty close to the real items.

cheers

Tony