Hewlett-Packard HP-15C
| Datasheet legend
Ab/c:
Fractions calculation
AC: Alternating current BaseN: Number base calculations Card: Magnetic card storage Cmem: Continuous memory Cond: Conditional execution Const: Scientific constants Cplx: Complex number arithmetic DC: Direct current Eqlib: Equation library Exp: Exponential/logarithmic functions Fin: Financial functions Grph: Graphing capability Hyp: Hyperbolic functions Ind: Indirect addressing Intg: Numerical integration Jump: Unconditional jump (GOTO) Lbl: Program labels LCD: Liquid Crystal Display LED: Light-Emitting Diode Li-ion: Lithium-ion rechargeable battery Lreg: Linear regression (2-variable statistics) mA: Milliamperes of current Mtrx: Matrix support NiCd: Nickel-Cadmium rechargeable battery NiMH: Nickel-metal-hydrite rechargeable battery Prnt: Printer RTC: Real-time clock Sdev: Standard deviation (1-variable statistics) Solv: Equation solver Subr: Subroutine call capability Symb: Symbolic computing Tape: Magnetic tape storage Trig: Trigonometric functions Units: Unit conversions VAC: Volts AC VDC: Volts DC |
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Hewlett-Packard HP-15C
It is easy to see why the HP-15C was a very popular scientific calculator. In addition to a rich set of scientific and engineering functions, the calculator also provided support for complex numbers and matrices; not only basic arithmetic, but also more esoteric features such as transcendental functions with complex arguments, or sophisticated matrix operations. The unit, like all HP 10C-series calculators, is robust, well designed, a pleasure to use, and unlike some of today's ultra high-end calculators, you can actually make sense of most of the calculator's functions without a 300-page manual. Add to this the fact that many 15-year old 10C-series calculators still run on their original set of three watch batteries, and one begins to wonder why these calculators are no longer made. (Then again, the financial calculator in the series, the HP-12C, is still being made. Can it be that in this one case, business folks have more common sense than engineers?)
Although other calculators that preceded the HP-15C also provided support for complex numbers, I believe the HP-15C was the first in which such support was fully integrated with other calculator functions. For instance, the Texas Instruments TI-59 had complex number support, but you needed to explicitly call special solid state library programs for this functionality. Once the HP-15C was in complex mode, however, all the buttons worked in the usual way; for instance, if you took the square root of -1, the calculator correctly yielded a complex result without you having to invoke any special function or subroutine.
The HP-15C provided, as one of its built-in functions, an extended factorial function that in fact calculated the Gamma function of x+1 for any real argument x. It did not, however, work for complex arguments. The impressive integration of complex functionality, however, makes it possible to create a complex implementation of the Gamma function on this calculator with quite a few bytes of memory to spare. In fact, with the exception of the TI-59 (on which such a program is possible, but much more complex, a lot slower, and requires use of a solid state library module), the HP-15C was the first programmable calculator on which such a complex implementation became feasible.
The program presented here calculates the Gamma function for any complex argument, with the exception of negative integers for which the function has no value. For instance, to calculate the Gamma function for i, key in the following: 1 I A. After a few seconds, the calculator displays the real part of the result (-0.154949828); to view the imaginary part (-0.498015669), press Re-Im. If you wish to clear complex mode after using the program, press CF 8.
001 - 42,21,11 LBL A
002 - 1 1
003 - 34 x-y
004 - 42,21, 2 LBL 2
005 - 43,30, 1 x>0
006 - 22 1 GTO 1
007 - 36 ENTER
008 - 33 Rv
009 - 20 ×
010 - 43 33 R^
011 - 1 1
012 - 40 +
013 - 22 2 GTO 2
014 - 42,21, 1 LBL 1
015 - 44 1 STO 1
016 - 42 30 Re-Im
017 - 44 3 STO 3
018 - 42 30 Re-Im
019 - 34 x-y
020 - 44 0 STO 0
021 - 42 30 Re-Im
022 - 44 2 STO 2
023 - 42 30 Re-Im
024 - 7 7
025 - 6 6
026 - 48 .
027 - 1 1
028 - 8 8
029 - 0 0
030 - 0 0
031 - 9 9
032 - 1 1
033 - 7 7
034 - 3 3
035 - 45 3 RCL 3
036 - 42 30 Re-Im
037 - 43 35 CLX
038 - 45 1 RCL 1
039 - 1 1
040 - 40 +
041 - 10 ÷
042 - 8 8
043 - 6 6
044 - 48 .
045 - 5 5
046 - 0 0
047 - 5 5
048 - 3 3
049 - 2 2
050 - 0 0
051 - 3 3
052 - 3 3
053 - 45 3 RCL 3
054 - 42 30 Re-Im
055 - 43 35 CLX
056 - 45 1 RCL 1
057 - 2 2
058 - 40 +
059 - 10 ÷
060 - 30 -
061 - 2 2
062 - 4 4
063 - 48 .
064 - 0 0
065 - 1 1
066 - 4 4
067 - 0 0
068 - 9 9
069 - 8 8
070 - 2 2
071 - 4 4
072 - 45 3 RCL 3
073 - 42 30 Re-Im
074 - 43 35 CLX
075 - 45 1 RCL 1
076 - 3 3
077 - 40 +
078 - 10 ÷
079 - 40 +
080 - 1 1
081 - 48 .
082 - 2 2
083 - 3 3
084 - 1 1
085 - 7 7
086 - 3 3
087 - 9 9
088 - 5 5
089 - 7 7
090 - 2 2
091 - 45 3 RCL 3
092 - 42 30 Re-Im
093 - 43 35 CLX
094 - 45 1 RCL 1
095 - 4 4
096 - 40 +
097 - 10 ÷
098 - 30 -
099 - 1 1
100 - 48 .
101 - 2 2
102 - 0 0
103 - 8 8
104 - 6 6
105 - 5 5
106 - 0 0
107 - 9 9
108 - 7 7
109 - 4 4
110 - 26 EEX
111 - 3 3
112 - 16 CHS
113 - 45 3 RCL 3
114 - 42 30 Re-Im
115 - 43 35 CLX
116 - 45 1 RCL 1
117 - 5 5
118 - 40 +
119 - 10 ÷
120 - 40 +
121 - 5 5
122 - 48 .
123 - 3 3
124 - 9 9
125 - 5 5
126 - 2 2
127 - 3 3
128 - 9 9
129 - 3 3
130 - 8 8
131 - 5 5
132 - 26 EEX
133 - 6 6
134 - 16 CHS
135 - 45 3 RCL 3
136 - 42 30 Re-Im
137 - 43 35 CLX
138 - 45 1 RCL 1
139 - 6 6
140 - 40 +
141 - 10 ÷
142 - 30 -
143 - 1 1
144 - 40 +
145 - 43 26 π
146 - 2 2
147 - 20 ×
148 - 11 √
149 - 20 ×
150 - 45 3 RCL 3
151 - 42 30 Re-Im
152 - 43 35 CLX
153 - 45 1 RCL 1
154 - 10 ÷
155 - 43 12 LN
156 - 45 3 RCL 3
157 - 42 30 Re-Im
158 - 43 35 CLX
159 - 45 1 RCL 1
160 - 5 5
161 - 48 .
162 - 5 5
163 - 40 +
164 - 43 12 LN
165 - 45 3 RCL 3
166 - 42 30 Re-Im
167 - 43 35 CLX
168 - 45 1 RCL 1
169 - 48 .
170 - 5 5
171 - 40 +
172 - 20 ×
173 - 40 +
174 - 45 3 RCL 3
175 - 42 30 Re-Im
176 - 43 35 CLX
177 - 45 1 RCL 1
178 - 30 -
179 - 5 5
180 - 48 .
181 - 5 5
182 - 30 -
183 - 12 ex
184 - 45 2 RCL 2
185 - 42 30 Re-Im
186 - 43 35 CLX
187 - 45 0 RCL 0
188 - 10 ÷
189 - 43 32 RTN
