(20S and 21S) Minimum and Maximum

[Eddie W. Shore]

The input/output format is the same for both minimum and maximum:

1. Enter the initial data point, press XEQ A.
2. Enter subsequent points, press XEQ B.
3. To find the minimum or maximum, depending on which program you use, press XEQ C.

The key codes for both the HP 20S and HP 21S for these programs are the same. Caution: this won’t always be the case. The HP 20S has a row dedicated to conversions while the HP 21S has a row dedicated to statistics.

HP 20S and HP 21S: Minimum

Code:


STEP    CODE    KEY
01    61, 41, A    LBL A
02    21, 1    STO 1
03    61, 26     RTN
04    61, 41, B    LBL B
05    21, 0    STO 0
06    31    INPUT
07    22, 1    RCL 1
08    61, 42    X≤Y?
09    51, 41, 1    GTO 1
10    71    Clear [ C ]
11    61, 26    RTN
12    61, 41, 1    LBL 1
13    51, 31     SWAP
14    21, 1    STO 1
15    71    Clear [ C ]
16    61, 26    RTN
17    61, 41, C    LBL C
18    22, 1    RCL 1
19    61, 26    RTN

Example:
Data Set: 9, 3, 6, 5, 7, 2, 4
Minimum: 2 (stored in R1)

HP 20S and HP 21S: Maximum

Code:


STEP    CODE    KEY
01    61, 41, A    LBL A
02    21, 1    STO 1
03    61, 26     RTN
04    61, 41, B    LBL B
05    21, 0    STO 0
06    31    INPUT
07    22, 2    RCL 2
08    51, 31    SWAP
09    61, 41    X≤Y?
10    51, 41, 2    GTO 2
11    71    Clear [ C ]
12    61, 26    RTN
13    61, 41, 2    LBL 2
14    21, 2    STO 2
15    71    Clear [ C ]
16    61, 26    RTN
17    61, 41, C    LBL C
18    22, 2    RCL 2
19    61, 26    RTN

Example:
Data Set: 9, 3, 6, 5, 7, 2, 4
Maximum: 9 (stored in R2)

This is two of my favorite programs I posted this year. I plan to make a version for the HP 12C soon. They are simple and versatile.