Enter values into the registers (R1-R4) and select an operation. This emulator performs basic arithmetic and trigonometric functions similar to the HP 35s.
Enter values and select an operation.
Understanding the HP 35s Scientific Calculator and its Operations
The Hewlett-Packard HP 35s is a classic scientific calculator renowned for its Reverse Polish Notation (RPN) input method and robust functionality. This emulator aims to replicate some of its core mathematical operations, focusing on how numbers are stored and manipulated. Unlike financial calculators, scientific calculators deal with a wide range of mathematical and physical computations.
Registers (R1-R4)
The HP 35s, while primarily using a stack, can be thought of in terms of registers for simpler emulation. In this emulator, we use four registers (R1, R2, R3, R4) to store input values. Operations typically take values from specific registers, perform a calculation, and often store the result back into one of the registers or a primary display (represented by our 'result' output).
Mathematical Operations
This emulator supports several fundamental mathematical operations:
Addition (+), Subtraction (-), Multiplication (*), Division (/): These are standard arithmetic operations. In a true RPN calculator, operands are pushed onto a stack, and the operator consumes the top two, pushing the result. Here, we simulate by taking values from R1 and R2 for binary operations.
Sine (sin), Cosine (cos), Tangent (tan): These trigonometric functions operate on a single input, typically assumed to be in radians unless specified otherwise. For simplicity, this emulator applies them to the value in R1.
Square Root (sqrt): Calculates the non-negative square root of a number. Applied to the value in R1.
Power (x^y): Calculates 'x' raised to the power of 'y'. In this emulator, we use R1 as the base (x) and R2 as the exponent (y).
Logarithm (log10), Natural Logarithm (ln): These are base-10 and base-e logarithms, respectively. Applied to the value in R1.
How to Use This Emulator
1. Enter your initial numerical values into the Register R1 and R2 fields. For operations requiring more inputs, R3 and R4 can be used, though this basic emulator primarily uses R1 and R2.
2. Select the desired mathematical operation from the buttons.
3. The result of the operation will be displayed below.
4. Use the "Clear All" button to reset all registers and the result.
Example Usage:
Scenario 1: Calculate 12.5 * 4.2
Enter 12.5 in Register R1.
Enter 4.2 in Register R2.
Click the Multiply (*) button.
Result: 52.5
Scenario 2: Calculate the square root of 144
Enter 144 in Register R1.
Click the Square Root (sqrt) button.
Result: 12
Scenario 3: Calculate 3 raised to the power of 4
Enter 3 in Register R1.
Enter 4 in Register R2.
Click the Power (x^y) button.
Result: 81
function getInputValue(id) {
var inputElement = document.getElementById(id);
var value = parseFloat(inputElement.value.replace(/,/g, ")); // Remove commas for parsing
if (isNaN(value)) {
return NaN; // Return NaN if parsing fails
}
return value;
}
function setDisplay(value) {
var resultElement = document.getElementById('result');
if (value === NaN || value === Infinity || value === -Infinity) {
resultElement.textContent = "Error";
} else if (typeof value === 'number') {
// Format numbers to avoid scientific notation for reasonable ranges, but allow it for very large/small numbers
if (Math.abs(value) 1e-6) {
resultElement.textContent = value.toLocaleString(undefined, { maximumFractionDigits: 10 });
} else {
resultElement.textContent = value.toPrecision(10);
}
} else {
resultElement.textContent = value; // For strings like "Error"
}
}
function performOperation(operator) {
var r1 = getInputValue('register1');
var r2 = getInputValue('register2');
var r3 = getInputValue('register3'); // Not used in basic ops, but available
var r4 = getInputValue('register4'); // Not used in basic ops, but available
var result = NaN;
if (operator === '+') {
if (!isNaN(r1) && !isNaN(r2)) result = r1 + r2;
} else if (operator === '-') {
if (!isNaN(r1) && !isNaN(r2)) result = r1 – r2;
} else if (operator === '*') {
if (!isNaN(r1) && !isNaN(r2)) result = r1 * r2;
} else if (operator === '/') {
if (!isNaN(r1) && !isNaN(r2)) {
if (r2 === 0) {
result = NaN; // Division by zero
} else {
result = r1 / r2;
}
}
} else if (operator === 'sin') {
if (!isNaN(r1)) result = Math.sin(r1); // Assumes radians
} else if (operator === 'cos') {
if (!isNaN(r1)) result = Math.cos(r1); // Assumes radians
} else if (operator === 'tan') {
if (!isNaN(r1)) result = Math.tan(r1); // Assumes radians
} else if (operator === 'sqrt') {
if (!isNaN(r1) && r1 >= 0) result = Math.sqrt(r1);
else result = NaN; // Square root of negative number
} else if (operator === 'pow') {
if (!isNaN(r1) && !isNaN(r2)) result = Math.pow(r1, r2);
} else if (operator === 'log') { // Log base 10
if (!isNaN(r1) && r1 > 0) result = Math.log10(r1);
else result = NaN; // Log of non-positive number
} else if (operator === 'ln') { // Natural Log (base e)
if (!isNaN(r1) && r1 > 0) result = Math.log(r1);
else result = NaN; // Log of non-positive number
}
// Attempt to store result back into R1 for chained operations
if (!isNaN(result)) {
document.getElementById('register1').value = result.toString();
}
setDisplay(result);
}
function clearAll() {
document.getElementById('register1').value = '0';
document.getElementById('register2').value = '0';
document.getElementById('register3').value = '0';
document.getElementById('register4').value = '0';
setDisplay("Enter values and select an operation.");
}