Texas Instruments TI-66
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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Texas Instruments TI-66
After the failure of the infamous TI-88 project, Texas Instruments was stranded without a product that could meet the challenge represented by Hewlett-Packard's amazing HP-41 calculator. The solution was to seek help from other manufacturers. The TI-66, an obvious successor to TI's hugely popular TI-58/TI-59 product line, is a calculator built by Toshiba, with Toshiba components inside. A less ambitious machine than the HP-41, the TI-66 was nevertheless a quite capable device. Like the HP-41, it offered an alphanumeric display; its programming model, however, is very similar to that of the TI-59. It lacked the HP-41's fabulous expandability, but it did have a proprietary serial port that allowed it to be connected to the PC-200 printer. (The same port appeared on the BA-55.)
Up to 512 program steps or 64 memories are enough for many complex problems. The machine contained numerous improvements over the TI-58C, which can be considered its closest predecessor with its continuous memory. In addition to the low power alphanumeric display, the calculator offered mnemonic display of program steps, a program entry mode that always showed the most recently entered step (as opposed to the next, usually blank, program step), and a pleasant shape and appearance in a small form factor. About the only drawback, when compared with the TI-58C, is the lack of a module port; gone were the solid state software modules that made the TI-58/TI-59 machines so versatile. (Then again, those modules were never as popular as they could have been, so perhaps TI had a solid reason for dropping this feature.)
Internally, these machines reflect the bold new age of extreme simplicity: a single circuit board that also serves as the keyboard backplate, with two surface mounted chips and a couple of discrete components. It was somewhat of a surprise to me when I realized that the machine's memory chip is an off-the-shelf component in a large, easy-to-solder DIP socket. However, this made it possible for me to repair one of my TI-66s that had a working processor but dysfunctional memory.
To demonstrate programming on the TI-66, here is my favorite programming example, an implementation of the Gamma function:
000 LBL 001 A 002 x-t 003 1 004 STO 005 00 006 LBL 007 x-t 008 0 009 x-t 010 x>=t 011 GTO 012 PRD 013 00 014 + 015 1 016 = 017 x-t 018 GTO 019 x-t 020 LBL 021 GTO 022 STO 023 01 024 . 025 1 026 8 027 0 028 0 029 9 030 1 031 7 032 2 033 9 034 4 035 + 036 7 037 6 038 = 039 ÷ 040 ( 041 RCL 042 01 043 + 044 1 045 ) 046 - 047 ( 048 . 049 5 050 0 051 5 052 3 053 2 054 0 055 3 056 2 057 9 058 4 059 + 060 8 061 6 062 ) 063 ÷ 064 ( 065 RCL 066 01 067 + 068 2 069 ) 070 + 071 ( 072 . 073 0 074 1 075 4 076 0 077 9 078 8 079 2 080 4 081 8 082 3 083 + 084 2 085 4 086 ) 087 ÷ 088 ( 089 RCL 090 01 091 + 092 3 093 ) 094 - 095 ( 096 . 097 2 098 3 099 1 100 7 101 3 102 9 103 5 104 7 105 2 106 5 107 + 108 1 109 ) 110 ÷ 111 ( 112 RCL 113 01 114 + 115 4 116 ) 117 + 118 ( 119 . 120 2 121 0 122 8 123 6 124 5 125 0 126 9 127 7 128 3 129 9 130 + 131 1 132 ) 133 ÷ 134 1 135 0 136 0 137 0 138 ÷ 139 ( 140 RCL 141 01 142 + 143 5 144 ) 145 - 146 5 147 . 148 3 149 9 150 5 151 2 152 3 153 9 154 3 155 8 156 5 157 ÷ 158 1 159 0 160 0 161 0 162 x² 163 ÷ 164 ( 165 RCL 166 01 167 + 168 6 169 ) 170 + 171 1 172 + 173 1 174 . 175 9 176 ÷ 177 1 178 0 179 0 180 0 181 0 182 0 183 x² 184 = 185 × 186 ( 187 2 188 × 189 π 190 ) 191 √ 192 ÷ 193 RCL 194 01 195 = 196 lnx 197 + 198 ( 199 RCL 200 01 201 + 202 5 203 . 204 5 205 ) 206 lnx 207 × 208 ( 209 RCL 210 01 211 + 212 . 213 5 214 ) 215 - 216 RCL 217 01 218 - 219 5 220 . 221 5 222 = 223 INV 224 lnx 225 ÷ 226 RCL 227 00 228 = 229 RTN