Improving the solver experience on the 41C

[Ángel Martin]

Very nice improvement on Stefan Vorkoetter's program; here's my proposal using the data entry flag F22 to re-write your SLV routine as follows:

Code:


1    LBL "SLV+
2    "F. NAME?"
3    AON
4    STOP
5    AOFF
6    ASTO 06
7    LBL 01
8    SF 05
9    XEQ IND 06
10    CF 22
11    PROMPT
12    GTO 01
13    LBL A
14    1
15    GTO 02
16    LBL B
17    2
18    GTO 02
19    LBL C
20    3
21    GTO 02
22    LBL D
23    4
24    GTO 02
25    LBL E
26    5
27    LBL 02
28    FC? 22
29    GTO 00
30    X<>Y
31    STO IND Y
32    GTO 01
33    LBL 00
34    STO 00
35    1
36    1 E-99
37    "a^b=?"
38    PROMPT
39    CLA
40    ARCL 06
41    CF 05
42    FROOT
43    STOP
44    GTO 01
45    END

Only 45 steps are needed, and a bunch of bytes are saved as well. Also no need to use [SHIFT] to determine the unknown - so it's standard with the other solvers, like the TMV$. So you'll enter all the knowns and then press the soft-key corresponding to the unknown to trigger the SOLVE process. BTW I've used FROOT from the SandMath instead..

Writing an MCODE equation solver has always lured me but I guess I don't know enough to tackle the job.

BTW - There's one ROM image I prepared a while ago that deals with this very same subject; it's called "Interchangeable Solutions" and contains the FOCAL programs of the same name available at TOS? (written by Humbert Hans Suarez, from the User's Program Library Europe, REF#01475C). It's a tad more complex but quite flexible in the number of variables and governing equations.