Problem when programming in HP 35s and other calculators

[Dieter]

(08-02-2018 08:30 PM)math7 Wrote:  Hello, I think the HP 35s is a good calculator, programmable with good 30KB memory, elegant and easy to use. But I'm doing some programs and I found the programs that can be called with a label, and that you can only use labels from A to Z and only one character for what I understood in the manual. So, how can you do it if you have more than 30 programs stored in the HP 35 for different things, if you can only use 26 labels, one for each program?

26 different programs is quite a lot for such a calculator. Earlier HPs (and calculators from other manufacturers) had 5 or 10 label keys, sometimes even less, or they were limited to 10 routines that could be called by GSB 0...GSB 9. Others even had no labels at all.

The 35s can use 26 different alpha labels. But you can have as many starting points within these programs as you like. Remember: [XEQ] A [ENTER] is just a shortcut for XEQ A001, i.e. start program A at its line 001. But you can just as well start a program with XEQ A010 or XEQ A222. This way you could for instance have a program with five different functions that are called via XEQ A001, XEQ A002, ... XEQ A005:

Code:

A001 GTO A170 // jump to where the first function starts
A002 GTO A093 // jump to where the second function starts
A003 GTO A123 // jump to where the third function starts
A004 GTO A030 // jump to where the fourth function starts
A005 ... // fifth function starts here
...
A029 RTN // fifth function ends here
A030 ... // fourth function starts here
...
A092 RTN // fourth function ends here
A093 ... // second function starts here
...
etc.

(08-02-2018 08:30 PM)math7 Wrote:  I think this is a major limitation in the programming of this calculator and similar HP ones!

If you really think so, get an HP-41C/CV/CX or an HP-42s. Or a DM-42. Here you can have named labels with up to six or seven characters.

(08-02-2018 08:30 PM)math7 Wrote:  Although you have enough memory, you can limit yourself to only 26 programs or less,

Memory is not only intended for programs, but for data as well. Imagine what size of a matrix you can invert on the 35s, even compared to a 41CV.

(08-02-2018 08:30 PM)math7 Wrote:  ...and if you can use a program with several subroutines each one has to carry your label too, then how to program more?

I don't understand what you mean here. Please explain in detail.

Generally speaking, subroutines within a program do not need additional labels. If your program starts with LBL C then its subroutines can be called with XEQ C050, XEQ C123 etc.

Dieter