The Museum of HP Calculators

Sorting Numbers for the HP-41

This program is supplied without representation or warranty of any kind. Jean-Marc Baillard and The Museum of HP Calculators therefore assume no responsibility and shall have no liability, consequential or otherwise, of any kind arising from the use of this program material or any part thereof.

Overview

1°) A Focal Program
2°) Micro-Code Routine ( Contiguous Registers only )

1°) A Focal Program

01 LBL "SORT"
02 SIGN
03 LBL 01
04 LASTX
05 LASTX
06 RCL IND L                                    if you don't have an HP-41CX, replace lines 08 to 13 by
07 LBL 02
08 X<=NN?                                        RCL IND Y
09 GTO 03                                          X>Y?               ( or X<=Y? to sort in decreasing order )
10 X<>Y                                             GTO 03
11 STO Y                                            X<>Y
12 RCL IND X                                    LASTX
13 LBL 03                                           +
14 ISG Y                                             LBL 03
15 GTO 02                                          RDN
16 X<> IND L
17 STO IND Z
18 ISG L
19 GTO 01
20 END

( 40 bytes )

STACK INPUT OUTPUT

X bbb.eeeii /

where bbb.eeeii is the control number of the array.

-For example, to sort numbers in registers R01 R03 R05 R07 , key in

1.00702 XEQ "SORT"

-Execution time is of the order of 47 seconds for an array of 20 numbers
--------------------------------- 17 minutes -------------- 100 --------

-This program uses a selection sort.
-The numbers are sorted in increasing order.
-If you want to sort in decreasing order, replace line 08 by X>=NN?

2°) Micro-Code Routine ( Contiguous Registers only )

-The following routine uses the "Bubble Sort" which is probably the worst sorting-algorithm...
-However, it is approximately 40 times as fast as the program above!

Code Mnemonics

094     "T"
012     "R"
00F    "O"
013     "S"
0F8     READ 3(X)                       The first executable word
361     ?NCXQ                             This execute instruction
050      14D8                                 checks for alpha data
284      CLRF 7
2FE     ?C#0 MS                          These 4 blue lines ( and the 3 other blue lines below )
013      JNC +02                           allow to sort in decreasing order if the input is negative.
288      SETF 7
05E      C=0 MS
084      CLRF 5
0ED     ?NCXQ
064      193B
226      C=C+1 S&X
226      C=C+1 S&X
226      C=C+1 S&X
088      SETF 5
0ED     ?NCXQ
064      193B
070      N=C ALL
0F8      READ 3(X)
05E      C=0 MS
0ED     ?NCXQ
064      193B
260      SETHEX
38D     ?NCXQ
008      02E3
0F0      C<>N ALL
38D     ?NCXQ
008      02E3
10E      A=C ALL
378      READ 13(c)
03C     RCR 3
146      A=A+C S&X
066      A<>B S&X
10E      A=C ALL
0B0      C=N ALL
206      C=C+A S&X
066      A<>B S&X
306      ?A<C S&X
013      JNC + 02
0A6     A<>C S&X
070      N=C ALL
130      LDI S&X                       200 hexadecimal = 512 decimal is the correct value if you have an HP-41CV/CX or an HP-41C with a quad memory module.
200      CON: 512                      Replace this line by 100h = 256d if you have an HP-41C without any memory module.
306      ?A<C S&X
381      ?NCGO                        -If register Rbb or Ree don't exist,
00A      02E0                              you'll get a "NON EXISTENT" message
0B0      C=N ALL
1BC     RCR 11
11A      A=C M
0AE     A<>C ALL
033      JNC +06
270      RAMSLCT
0EE     C<>B ALL
2F0      WRIT DATA
198      C=M ALL
266      C=C-1 S&X
158      M=C ALL
106      A=C S&X
03C     RCR 3
070      N=C ALL
366      ?A#C S&X
3A0     ?NC RTN
270      RAMSLCT
038      READ DATA
0EE     C<>B ALL
198      C=M ALL
106      A=C S&X
0B0      C=N ALL
366      ?A#C S&X
373      JNC -12
226      C=C+1 S&X
070      N=C ALL
270      RAMSLCT
038      READ DATA
06E      A<>B ALL
37E      ?A#C MS
023       JNC +04
35E      ?A#0 MS
0B7       JC +16
0A3      JNC +14
21C      PT=2
362       ?A#C @PT                                          these 25 green lines compare the numbers in the CPU registers A and C,
03B      JNC +07                                               place the lowest one in A and the highest one in C.
342       ?A#0 @PT
017       JC +02
0AE      A<>C ALL
2EE      ?C#0 ALL
057       JC +0A
05B      JNC +0B
366       ?A#C S&X
023       JNC +04
306       ?A<C S&X
02F       JC +05
01B       JNC +03
31A      ?A<C M
017       JC +02
0AE      A<>C ALL
35E       ?A#0 MS
013       JNC +02
0AE      A<>C ALL
28C      ?FSET 7
013       JNC +02
0AE      A<>C ALL
0EE       C<>B ALL
0B0       C=N ALL
266       C=C-1 S&X
270       RAMSLCT
0AE      A<>C ALL
2F0       WRIT DATA
2A3       JNC -2C

      STACK        INPUT      OUTPUT

           X     +/- bbb.eee     +/- bbb.eee

Where bbb.eee is the control number of the array.
The stack is actually unchanged.

-A positive input will sort the numbers in increasing order
-A negative --------------------------- decreasing order

Notes:

-Execution time is of the order of 25 seconds for an array of 100 numbers
--------------------------------- 100---------------------- 200 --------
-It is proportional to the square of the number of elements.

-In fact, the 4th , 5th , .... decimals of the input are not taken into account

-You can also key in eee.bbb instead of bbb.eee
-For instance, if you have to sort the numbers in registers R00 R01 ............ R99
simply press 99 XEQ "SORT" instead of 0.099 XEQ "SORT" ( both work )

-If you do not need to sort in decreasing order, delete the 7 lines written in blue ( especially the last 3 ones: 28C 013 0AE )
and replace the last line ( written in red ) by

2BB JNC -29 the routine will run 6% faster.

-There is no risk of "crash" if the registers contain alpha data, but the sorting may be quite fanciful!
-For example, if registers R01 thru R05 contain "A" "B" "Z" "AB" "ABC"
1.005 XEQ "SORT" will produce "Z" "B" "A" "ABC" "AB" in these registers...
-It is due to the way alpha strings are coded in a register.

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