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Wikipedia

TI SR-50

January 01, 1970

The SR-50 was Texas Instruments' first scientific pocket calculator with trigonometric and logarithm functions. It enhanced their earlier SR-10 and SR-11 calculators, introduced in 1973, which had featured scientific notation, squares, square root, and reciprocals, but had no trig or log functions, and lacked other features. The SR-50 was introduced in 1974 and sold for US$170.[1] It competed with the Hewlett-Packard HP-35.

SR-50 (1974)
Printed circuit board. Data code 035: 3rd week 1975

Design edit

The SR-50 measured 5-3/4 inches long by 3-1/8 inches wide by 1-3/16 inches high (147 mm by 78 mm by 31 mm) and was powered by a rechargeable NiCad battery pack, built from three soldered AA cells. It had 40 keys, and flat sliding switches for degrees/radians and on/off. "SR" stood for "slide rule."

The SR-50 had a red LED display with a signed ten-digit mantissa plus a signed two-digit exponent for floating point numbers (negative values were indicated with a leading minus sign and positive values with no sign). Internally, calculations were performed with a 13-digit mantissa, providing much greater calculation accuracy than the 10-digit precision of most scientific calculators of the time. After the leading sign, digits consisted of a seven-segment display plus decimal point. A blinking display indicated an error, such as a calculation error or an overflow or underflow condition.

Like most scientific calculators, the SR-50 mostly used ordinary infix notation, as opposed to the postfix Reverse Polish Notation (RPN) employed by its competitor, the Hewlett Packard HP-35. The SR-50 followed the standard order of operations by performing unary (single-argument) operations (reciprocal, square, square root, log, trig and hyperbolic trig functions) immediately, and multiplication, division, root, and power operations before addition and subtraction operations. But: you had to enter parameters first when using single-argument operations (e. g. 30 sin). As an example, the keypresses to calculate "3 x log(4) + 5" was entered almost as written, namely "3 x 4 log + 5 =". This is because the calculator would execute the log function before performing the multiplication operation, and complete the multiplication operation before executing the addition operation. It did so by having unary operations operate on the X register, addition and subtraction operate on the X and Z registers, and multiplication, division, power, and root functions operate on the X and Y registers in its operational stack.

An unusual feature of the SR-50 was that its included functions like factorial and hyperbolic trig functions, which were found on very few calculators (including the HP-35 and HP-45) at the time. The user invoked the hyperbolic functions by entering the function argument and then pressing the "hyp" key, followed by the "sin", "cos", or "tan" function key. The inverse hyperbolic functions were accessed by first pressing the "arc" and "hyp" keys (in any order) and then pressing the "sin", "cos", or "tan" key. Hyperbolic trig arguments were always assumed to be in radians regardless of the setting of the degree/radian (D/R) mode switch. In addition to its three-register operational stack, consisting of X, Y, and Z registers, the SR-50 also included one memory (M) register to which the value in the X (display) register could be directly added using the "summation" key.[2] The SR-50 had very fast trig functions (about half a second to evaluate each function) and was a popular calculator to use in contests involving pocket calculators.

Technical data edit

Descendants edit

The SR-50 was followed by the more advanced model SR-51. The SR-51 had the same physical dimensions but added a 2nd function for most buttons. Most notable among the added functions were the ability to enter x:y pairs and do linear regression analysis on them. The later and lighter versions SR-50A and SR-51II and SR-51III were based on smaller ICs and battery packs and reached broadest distribution.

A further update resulted in the programmable model SR-52 in late 1975. It was thicker and longer and could perform 224 program steps recorded on magnetic cards, similar to its competitor HP-65. The card was pulled through the reader by an electric motor. The matte white upper face of the cards could be marked with pen or pencil to indicate the program and the functions assigned to the calculator's programmable keys.[clarification needed] The card could be stored in a slot above the programmable keys with its markings visible.

In 1976 Texas Instruments released the TI-30 budget calculator at one-third the price of the SR-50, so sales of the SR-50 quickly dropped.

  •  
    SR-10 (predecessor)
  •  
    SR-51A with statistical functions
  •  
    TI SR-52 on display at the Musée Bolo, EPFL, Lausanne.
  •  
    TI-30
  •  
    TI-55-II

References edit

  1. ^ 20 Years of Texas Instruments Consumer Products
  2. ^ Texas Instruments SR-50 Slide Rule Calculator User's Manual

January 01, 1970
texas, instruments, first, scientific, pocket, calculator, with, trigonometric, logarithm, functions, enhanced, their, earlier, calculators, introduced, 1973, which, featured, scientific, notation, squares, square, root, reciprocals, trig, functions, lacked, o. The SR 50 was Texas Instruments first scientific pocket calculator with trigonometric and logarithm functions It enhanced their earlier SR 10 and SR 11 calculators introduced in 1973 which had featured scientific notation squares square root and reciprocals but had no trig or log functions and lacked other features The SR 50 was introduced in 1974 and sold for US 170 1 It competed with the Hewlett Packard HP 35 SR 50 1974 Printed circuit board Data code 035 3rd week 1975 Contents 1 Design 2 Technical data 3 Descendants 4 ReferencesDesign editThe SR 50 measured 5 3 4 inches long by 3 1 8 inches wide by 1 3 16 inches high 147 mm by 78 mm by 31 mm and was powered by a rechargeable NiCad battery pack built from three soldered AA cells It had 40 keys and flat sliding switches for degrees radians and on off SR stood for slide rule The SR 50 had a red LED display with a signed ten digit mantissa plus a signed two digit exponent for floating point numbers negative values were indicated with a leading minus sign and positive values with no sign Internally calculations were performed with a 13 digit mantissa providing much greater calculation accuracy than the 10 digit precision of most scientific calculators of the time After the leading sign digits consisted of a seven segment display plus decimal point A blinking display indicated an error such as a calculation error or an overflow or underflow condition Like most scientific calculators the SR 50 mostly used ordinary infix notation as opposed to the postfix Reverse Polish Notation RPN employed by its competitor the Hewlett Packard HP 35 The SR 50 followed the standard order of operations by performing unary single argument operations reciprocal square square root log trig and hyperbolic trig functions immediately and multiplication division root and power operations before addition and subtraction operations But you had to enter parameters first when using single argument operations e g 30 sin As an example the keypresses to calculate 3 x log 4 5 was entered almost as written namely 3 x 4 log 5 This is because the calculator would execute the log function before performing the multiplication operation and complete the multiplication operation before executing the addition operation It did so by having unary operations operate on the X register addition and subtraction operate on the X and Z registers and multiplication division power and root functions operate on the X and Y registers in its operational stack An unusual feature of the SR 50 was that its included functions like factorial and hyperbolic trig functions which were found on very few calculators including the HP 35 and HP 45 at the time The user invoked the hyperbolic functions by entering the function argument and then pressing the hyp key followed by the sin cos or tan function key The inverse hyperbolic functions were accessed by first pressing the arc and hyp keys in any order and then pressing the sin cos or tan key Hyperbolic trig arguments were always assumed to be in radians regardless of the setting of the degree radian D R mode switch In addition to its three register operational stack consisting of X Y and Z registers the SR 50 also included one memory M register to which the value in the X display register could be directly added using the summation key 2 The SR 50 had very fast trig functions about half a second to evaluate each function and was a popular calculator to use in contests involving pocket calculators Technical data editALU Arithmetic and Logic Unit TMC0501 SCOM Scanning Read Only Memory TMC0521 Display driver 2 27882 Power NiCd battery pack BP1 3 6 V charger AC9200 or AC9900Descendants editThe SR 50 was followed by the more advanced model SR 51 The SR 51 had the same physical dimensions but added a 2nd function for most buttons Most notable among the added functions were the ability to enter x y pairs and do linear regression analysis on them The later and lighter versions SR 50A and SR 51II and SR 51III were based on smaller ICs and battery packs and reached broadest distribution A further update resulted in the programmable model SR 52 in late 1975 It was thicker and longer and could perform 224 program steps recorded on magnetic cards similar to its competitor HP 65 The card was pulled through the reader by an electric motor The matte white upper face of the cards could be marked with pen or pencil to indicate the program and the functions assigned to the calculator s programmable keys clarification needed The card could be stored in a slot above the programmable keys with its markings visible In 1976 Texas Instruments released the TI 30 budget calculator at one third the price of the SR 50 so sales of the SR 50 quickly dropped nbsp SR 10 predecessor nbsp SR 51A with statistical functions nbsp TI SR 52 on display at the Musee Bolo EPFL Lausanne nbsp TI 30 nbsp TI 55 IIReferences edit 20 Years of Texas Instruments Consumer Products Texas Instruments SR 50 Slide Rule Calculator User s Manual Retrieved from https en wikipedia org w index php title TI SR 50 amp oldid 1216471553, wikipedia, wiki, book, books, library,

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