(04-27-2020 09:42 AM)J-F Garnier Wrote: Hello HP71 fans and HP Basic friends,

I released an update of the Math ROM 2 test version (now 2b2). It adds 3 new MAT statements taken from the HP75, Series 80 and Series 200/300 Basic: MAT ... CROSS, MAT ... CSUM and MAT ... RSUM.

With this version, I'm getting closer and closer to the HP75 Math ROM features (one of my goals with this project).

Adding new MAT statements was not trivial. The Math ROM was not designed to do so, and the simple idea to just add the needed keywords and execution code was causing serious compatibility problems. I found a way to overcome these problems, I will document it in a future article.

I know it's very late to propose a new MATH ROM version, after more than 35 years, and that the community interest may be limited. Technically I could have done it 10 or 15 years ago, I had all the tools but it's only now that I have the time to do it (reversing the Math ROM is VERY time consuming). Anyway, it's a great project for me and gives me a lot of fun ! A good part of the fun is to write the manual in the HP style of the time.

A little challenge for you : during my tests I found a minor problem in some of the new keywords of the previous test version (2b1, see post above). I didn't fix it yet (so still in 2b2, will fix it in a later version) and your mission, would you accept it, is to find the problem...

It's not a major problem, it will not crash your HP71 nor make your big engineering calculations completely fail, but still this is not fully correct and so it may be called a bug.

Hint: the HP75 and Series 80 don't have (and *can't* have) the same problem with these keywords...

Have fun !

J-F

I'm not so deep in mathematics, but I like your enthusiasm with developing the math modul to the next step. Maybe it makes me more curious to get more in touch with the matrix functions.

THANKS for your great work and share it with us.

Erwin