HP-81, Fail :-(

[teenix]

(12-21-2018 09:53 AM)Thomas Okken Wrote:  Not criticizing, but curious: what is the problem? If you can emulate the hardware and you have a ROM image, doesn't the math take care of itself?

The hardware is just a "shell". The display, keyboard, switches and printer are functional but no code behind it all. I don't have the source code, I only have the owners manual to go by. If I had the source code, I'm sure I could figure it all out, but I think getting hold of it is unlikely.

There is a list of equations at the back of the manual, and I have translated and code tested some of them, but not all as I can't work them out. For example, finding the bond yield on page 121 by translating the previous bond price equation to solve for (i), (yuck, unfortunately my math brain is not that good) and I can't even be sure there are no errors in the equations. The manual has plenty of corrections added.

It gets even more complicated with different operating modes, and perhaps not all the required equations are there.

I've spent quite a bit of time on it so far, but I realised it may not be practicable to continue.

cheers

Tony