The Museum of HP Calculators

Butterworth Active Filter Desgn, Low Pass for the HP-41C/CV/CX

This program is Copyright © HP and is used here by permission. It was originally printed in the HP-67 Filters Solution Book. This program was entered and uploaded by Tony Duell.

This program is supplied without representation or warranty of any kind. Tony Duell, Hewlett Packard 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.

Documentation Information (CD or source code)
How to get this Program to your Calculator (via HP-IL, disk, wand, and fingers)
Download Binary (.raw) program for disk or PC HP-IL Card download
Download Hexadecimal (.dat) program for Serial Port download

Program Listing

LINE  KEYS
 01 LBL "BAFDLP"
 02 LBL 10
 03 LBL A
 04 STO 04
 05 RDN
 06 STO 03
 07 RDN
 08 STO 02
 09 RDN
 10 STO 01
 11 RCL 03
 12 XEQ 14
 13 RCL 01
 14 XEQ 14
 15 /
 16 LOG
 17 RCL 04
 18 RCL 02
 19 /
 20 LOG
 21 /
 22 2
 23 /
 24 .99
 25 +
 26 INT
 27 STO 05
 28 RCL 02
 29 RCL 01
 30 XEQ 14
 31 RCL 05
 32 2
 33 *
 34 1/X
 35 Y^X
 36 /
 37 STO 06
 38 RCL 05
 39 RTN
 40 LBL 11
 41 LBL B
 42 ENTER
 43 ENTER
 44 RCL 06
 45 /
 46 RCL 05
 47 2
 48 *
 49 Y^X
 50 1
 51 +
 52 LOG
 53 10
 54 *
 55 RTN
 56 LBL 14
 57 LBL E
 58 10
 59 /
 60 10^X
 61 1
 62 -
 63 RTN
 64 LBL 12
 65 LBL C
 66 PI
 67 2
 68 *
 69 *
 70 RTN
 71 LBL 13
 72 LBL D
 73 PI
 74 /
 75 2
 76 /
 77 RTN
 78 LBL 15
 79 LBL a
 80 1
 81 STO 07
 82 RCL 05
 83 2
 84 /
 85 FRC
 86 0
 87 X=Y?
 88 GTO 19
 89 LBL 16
 90 LBL b
 91 RCL 05
 92 1
 93 -
 94 RCL 07
 95 XEQ 18
 96 STOP
 97 RCL 05
 98 RCL 07
 99 1
100 +
101 STO 07
102 X<=Y?
103 GTO 16
104 0
105 /
106 LBL 19
107 LBL e
108 RCL 05
109 1
110 +
111 RCL 07
112 1
113 -
114 XEQ 18
115 STOP
116 RCL 05
117 RCL 07
118 1
119 +
120 STO 07
121 X<=Y?
122 GTO 19
123 0
124 /
125 LBL 17
126 LBL c
127 RCL 06
128 RCL 05
129 2
130 *
131 Y^X
132 RTN
133 LBL 18
134 LBL d
135 2
136 *
137 +
138 PI
139 *
140 RCL 05
141 /
142 2
143 /
144 RCL 06
145 P-R
146 RTN
147 STOP
148 END

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