Model: -35A General: Name: Scientific Pocket Calculator Code-Name: none (Classic?) Family: Classic Logic: RPN Features: scientific Firsts: one at all (also: Classic, RPN, etc.) Introduction: Date: 1972-07-01 (from wall of fame, possibly 1972-02-01) Price: $395 Discontinuation: Date: 1975-02-01 Price: $195 Production-Run: ? Display: Type: LED, 7 segment Size: 1 line x 15 chars Number-Formats: sign, 10 mantissa, ., exp sign, 2 exp Annunciators: ............... battery low (true decimal has digit to itself) Data: User-Visible: Smallest: 1E-99 Largest: 9.999999999E99 Signif.-Digits: 10 Internal: Smallest: 1E-99 Largest: 9.999999999E99 Signif.-Digits: 10 Data-Types-and-Sizes: real, 7 bytes Memory: Named-Registers: X, Y, Z, T, S Flags: none Register-Usage: Z is duplicated into T after trig functions Numbered-Registers: none Program-Steps: none Program-Editing: none Program-Display: none User-RAM-Bytes: 35 Total-RAM-Bytes: 49 ROM-Bytes: 768 (10-bit words) Machine-State: prefix key state stack lift enable registers total of 7, 7-byte registers and 12 status bits File-Types: none Physical: Technology-Used: ? Processor: ? Chip-Count: 8 1820-0853 anode driver and system clock 1820-0854 cathode driers 1820-0855 clock driver 1820-0849 CPU control and keyboard scanner 1820-0848 CPU data 1818-0024 ROM (256 x 10), 10-pin can 1818-0026 ROM (256 x 10), 10-pin can 1818-0028 ROM (256 x 10), 10-pin can Power-Source: 3 nickel-cadmium AA cells, AC Continuous-Memory: none Expansion-Ports: none I/O-Ports: none Clock: none Length: 5.8 in Width: 3.2 in Height: 0.7 to 1.3 in Weight: 9 oz Temperature-Range: Operating: 0 to 40 deg C Charging: 10 to 40 deg C Storage: -40 to 55 deg C Keyboard: Switches: OFF / ON Shift-Keys: none User-Defined-Keys: none Key-Arrangement:: ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ***** ** ** ** * *** *** *** * *** *** *** * *** *** *** * *** *** *** Key-Labels-Base-Keyboard:: y x x log ln e CLR \v/x arc sin cos tan 1/x x<>y Rv STO RCL ENTER^ CHS EEX CLx - 7 8 9 + 4 5 6 x 1 2 3 \:- 0 . \pi Programmable-Operations:: none Non-Programmable-Operations:: + addition - subtraction 0-9, . enter digit or decimal point 1/x reciprocal ARC COS arc cosine ARC SIN arc sine ARC TAN arc tangent CHS change sign CLx clear X COS cosine EEX start an exponent, 1 not required ENTER^ enter e^x natural exponentiation ln natural logarithm log common logarithm RCL recall from register Rv roll the stack down SIN sine STO store in register TAN tangent x multiplication x<>y exchange x and y x^y power \:- division \pi constant, value 3.141592654 \v/x square root Menus:: none Bugs/ROM-Versions:: On early models, if you did: 2.02 ln e^x you got 2. More fully, we have the text of an official Hewlett-Packard errata sheet: HP-35 Errata Exponential Functions 1. This siutation involves the use of certain numbers, which, when used as the value of "x" in e^x, cause that function to give an- swers that are off by a maximum of one percent. The numbers are 0.,7030975114 and 0.995033085 x 10^-2, or integer multiples of the latter number though nine, by itself, or when added to the former. These num- bers are correct when used by themselves or derived as answers to expressions such as ln 2.02 (ln 2.02 = 0.7030975114). The idiosyncrasy is in the e^x function, not the logarithmic function. Additionally, since x^y = e^yln x, when yln x equals one of the numbers above, then x^y will also be off slightly less than one percent. To achieve a very good approximation of the proper operation with these numbers, you can simply leave off the last digit of the number to be used as "x" in e^x or x^y. 2. In e^x, when x = (-2291.072168 +/- 11.512924) x 10^J (J can equal 0 through 96), the HP-35 will indicate overflow (9.999999999 x 10^99) when it should indicate underflow (0). The numbers mentioned above are beyond the dynamic range of the calculator. Trigonometric functions 1. The HP-35 gives the following answers: arc sine 0.0002 = 5.729577893 x 10^-3 arc cosine 0.0002 = 89.99427042 arc tangent 0.0002 = 5.729577893 x 10^-3 The correct answers are: arc sine 0.0002 = 0.01145916 arc cosine 0.0002 = 89.98854 arc tangent 0.0002 = 0.1145916 2. The HP-35 gives the arc tangent of 1.00020002 as 45; the correct answer is 45.00573. This represents an error of ap- proximately one one-hundredth of one percent. 3. There is a deviation of approximately one one-hundredth of a percent in the arc sine and are cosine of these numbers (arc tangent is correct): 0.7071774882 0.7071774884 0.7071774883 0.7071774885 The HP-35 gives 45 for the arc sine and co- sine of these numbers; the arc sine should be approximately 45.005730, and the arc cosine should be approximately 44.994270. We are confident that this list represents the range of errors in the calculator. Hewlett hp Packard Advanced Products 10900 Wolfe Road, Cupertineo, CA 95014 Try: 0 CHS \v/ and you will get an error, even though it can take the square root of zero. These bugs _may_ have caused a recall. Rumor. Not confirmed. Notes:: "Original" non-programmable hand held slide rule. Had x^y not y^x! Price went down to $295 when the -45A was introduced. The trig functions compute in degrees only. The ROM was on three chips. All are active and read the same (8-bit) address. Only one is selected, and only that chip's data is returned. price changes: 1973-05-01 $295 1974-05-01 $225 1975-02-01 $195 Early units had a small hole to the right of the ON/OFF switch. This hole had an "on" light, which is of course redundant. Very early units just had "Hewlett-Packard" with no model number. Early models had labels printed above the key, not molded into the keys. The story is that it was called the 35 because it had 35 keys. The logic behind other calculator numbers is, shall we say?, less obvious. There is a rumor that 1 or 2 units were custom built with green LEDs for either Carl Hewlett or Dave Packard. The green LEDs drew much more power. ------------------------------------------------------------ letter from Jordi Hidalgo in DATAFILE V22 N1 p4, January/February 2003 Quoted from HP-35 Math Pac manual, page 168: How would you display all 1's, 2's, ... 9's? 1's: 9 e^x e^x 9 EEX 88 \:- 2's: 9 e^x e^x 4.5 EEX 77 \:- 3's: 9 e^x e^x 3 EEX 66 \:- 4's: 9 e^x e^x 2.25 EEX 55 \:- 5's: 9 e^x e^x 1.8 EEX 44 \:- 6's: 9 e^x e^x 1.5 EEX 33 \:- 7's: 7.777777777 EEX 7 8's: 9 e^x e^x 1.125 EEX 11 \:- 9's: 9 e^x e^x The author found a shorter way to do 7: 7's: 9 1/x 7 EEX 78 * Tony Duell has a nice "HP-35 Internals..." article in DATAFILE V22 N6 P11.
I am Craig A. Finseth.
Last modified Saturday, 2012-02-25T17:29:38-06:00.