Hp15c, using STO throws error 3. Did I break it?

[Spencer]

I'm using my 1985 hp15c to solve a 2nd order runge kutta scheme. A system of equations describing ballistic flight of an arrow through air. The program is about 60 lines long and uses only about 7 registers. I tried to STO 5 in the programming screen and it gave an error 3. Earlier I tried doing an f Lbl B and it gave error 4. It's almost like every single register does not exist. But earlier I made a 74 line program using almost all the 20 registers and it performed great. But now it's up in the air if I can even program at all. It's like it's not happy I put it through 18000 flops. I paid 200usd for this gem and I'm really afraid I broke it. Someone please help!

[Harald]

(07-22-2017 02:37 AM)Spencer Wrote:  I'm using my 1985 hp15c to solve a 2nd order runge kutta scheme. A system of equations describing ballistic flight of an arrow through air. The program is about 60 lines long and uses only about 7 registers. I tried to STO 5 in the programming screen and it gave an error 3. Earlier I tried doing an f Lbl B and it gave error 4. It's almost like every single register does not exist. But earlier I made a 74 line program using almost all the 20 registers and it performed great. But now it's up in the air if I can even program at all. It's like it's not happy I put it through 18000 flops. I paid 200usd for this gem and I'm really afraid I broke it. Someone please help!

You probably have a memory allocation problem.
Have a look at the manual:
http://www.hp.com/ctg/Manual/c03030589.pdf

[SlideRule]

(07-22-2017 02:37 AM)Spencer Wrote:  .. hp15c to solve a ... system of equations describing ballistic flight of an arrow .. program ... 60 lines ... 7 registers...

Is the algorithm / program proprietary? Are you inclined / free to share?

BEST!
SlideRule

[BobVA]

As Harald noted, it's hopefully just a memory allocation issue - if you press g MEM and hold the key down you'll get a display like: 19 46 0-0 (which is the default configuration)

The first number (19 in this case) is the highest numbered storage register available for use (includes the "i" register and count starts are register 0). If that's a lower number than 5, that would explain why you can't store above that. The manual explains how to change this.