Prime? for the HP 42s (original) (raw)

This program was written by Wanda Louise & BabyNous and is used here by permission.

This program is supplied without representation or warranty of any kind. The author 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

The Program assumes that there is already a Real Matrix, of any Dimensions, already in Memory called: Prime.

Input: X: Real Number

Running Output: LUFRN: > CD
Where:
LUFRN is the Lowest UnFactored Real Number
CD is the Countdown (SQRT(Current Real) - current factor)

Terminal Output:
X: [ 1x? Matrix ]
1:1= Original Real
1:→= Prime Factors

The Program

LINE KEYS 00 { 252-Byte Prgm } 01 ▶LBL "Prm?" 02 STO "CREAL" 03 √x 04 STO "SQRTCR" 05 2 06 STO "CFACT" 07 1 08 STO "SZPRIME" 09 1 10 DIM "Prime" 11 INDEX "Prime" 12 STOIJ 13 RCL "CREAL" 14 STOEL

15 ▶LBL a 16 CLA 17 ARCL "CREAL" 18 ⊢?": > " 19 RCL "SQRTCR" 20 ENTER 21 RCL "CFACT" 22 - 23 IP 24 ARCL ST X 25 AVIEW 26 RCL "SQRTCR" 27 RCL "CFACT" 28 X>Y? 29 GTO e 30 XEQ A 31 RCL "CFACT" 32 2 33 X=Y? 34 GTO 01 35 2 36 GTO 00

37 ▶LBL 01 38 1

39 ▶LBL 00 40 STO+ "CFACT" 41 GTO a

42 ▶LBL e 43 RCL "SZPRIME" 44 1 45 X≠Y? 46 GTO c 47 "Prime!!!" 48 AVIEW 49 GTO J

50 ▶LBL c 51 "Composite!!!" 52 AVIEW 53 RCL "CREAL" 54 1 55 X=Y? 56 GTO J 57 1 58 STO+ "SZPRIME" 59 RCL "SZPRIME" 60 DIM "Prime" 61 STOIJ 62 RCL "CREAL" 63 STOEL

64 ▶LBL J 65 CLST 66 RCL "Prime" 67 CLV "SZPRIME" 68 CLV "CFACT" 69 CLV "CREAL" 70 CLV "SQRTCR" 71 STOP

72 ▶LBL A 73 RCL "CREAL" 74 RCL "CFACT" 75 ÷ 76 ENTER 77 FP 78 X≠Y? 79 GTO B 80 R↓ 81 STO "CREAL" 82 √x 83 STO "SQRTCR" 84 1 85 STO+ "SZPRIME" 86 RCL "SZPRIME" 87 DIM "Prime" 88 STOIJ 89 RCL "CFACT" 90 STOEL 91 XEQ A

92 ▶LBL B 93 RTN 94 END

Variables

CREAL: Current Real SQRTCR: SQRT(CREAL) CFACT: Current Factor SZPRIME: Size of Prime Prime: Final Matrix

Go back to the software library
Go back to the main exhibit hall