Charles Babbage's Analytical Engine Simulator

Run Step Reset | Adding 2 numbers Quotient & Remainder Count Down Timer Multiplying 2 inputs Factorial of... Fibonacci Series Note-G Algorithm Load Program | Instruction SetAbout

00	01	02	03	04	05	06	07	08	09
10	11	12	13	14	15	16	17	18	19
20	21	22	23	24	25	26	27	28	29
30	31	32	33	34	35	36	37	38	39
40	41	42	43	44	45	46	47	48	49
50	51	52	53	54	55	56	57	58	59
60	61	62	63	64	65	66	67	68	69
70	71	72	73	74	75	76	77	78	79
80	81	82	83	84	85	86	87	88	89
90	91	92	93	94	95	96	97	98	99

Analytical Engine Emulator - © 101Computing.net

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About this Analytical Engine Emulator

This Analytical Engine is based on the designs of Charles Babbage Analytical Engine (designs produced in the 1830s). If it had been built, this mechanical machine/computer, would have been capable of executing programs: sets of instructions stored on punched cards. The analytical engine incorporated many of the key components of a computer from the electronic era (e.g. Vonn Neuman Processor Architecture). Effectively it includes an arithmetic logic unit (the mill), an integrated memory in the forms of key registers and a large store, a printer for outputing results and the ability to process instructions from punched cards and to control the execution flow in the form of sequencing, conditional branching and loops.

This emulator is designed for educational purposes. Note that there are a few differences between this emulator and the designs of the Analytical Engine. For instance, one key difference is the capacity of the store: the store for this online emulor has 100 different storage locations ranging from 00 to 99. In Charles Babbage designs, the plan was to have a store of 1,000 memory locations each containing a 50-digit number.

Find out more about his emulator on https://www.101computing.net/charles-babbages-analytical-engine-emulator/

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Instruction Set

The Analytical Engine was designed to accept set of instructions using punched cards, each punched card representing one instruction. Charles Babbage regrouped the different instructions into three main types of cards: Number Cards, Variable Carts and Operation Cards.

Opcode	Instruction	Example	Description
N	Number	N1 5	Used to store a given number (e.g. 5) in the store at a specific location (e.g. 1)
L	Load	L2	Load a value from the store, at a specified location (e.g. 2) to the Mill Ingress axis, leaving the store column unchanged.
Z	Load	Z2	Load a value from the store, at a specified location/column (e.g. 2) to the Mill Ingress axis, resetting the store column to 0.
S	Save	S2	Store the value currently in the Mill Egress axis to a given location/column in the Store.
+	Add	+	Add the values in the two Ingress Axes (ignoring the contents of the Primed Ingress Axis), and the result of this addition is stored in the Egress Axis.
-	Subtract	-	Subtract the values in the two Ingress Axes (ignoring the contents of the Primed Ingress Axis), and the result of this subtraction is stored in the Egress Axis.
x	Multiply	-	Multiply the values in the two Ingress Axes (ignoring the contents of the Primed Ingress Axis), and the result of this multiplication is stored in the Egress Axis.
/	Divide	/	The value in the first Ingress Axis is divided by the value in the second Ingress Axis. The quotient is placed on the Primed Egress Axis and the remainder on the Egress Axis.
<	Step up	<6	Step up (left right) by n digits in the Ingress Axis. e.g. <3 to multiply the Ingress value by 1,000.
>	Step down	>6	Step down (shift right) by n digits in the Ingress Axis. e.g. >3 to divide the Ingress value by 1,000.
CB+	Back Always	CB+7	To skip backward (and repeat) a given number of cards cards in the reader.
CB?	Back only if run-up lever is set	CB?7	To skip backward (and repeat) a given number of cards cards in the reader if run-up lever is set.
CF+	Forward Always	CF+7	To skip forward a given number of cards cards in the reader.
CF?	Forward only if run-up lever is set	CF?7	To skip forward a given number of cards cards in the reader if run-up lever is set.
P	Print	P	Print the value on the mill axis that the most recent operation most recently modified (e.g. the Mill Egress axis after an arithmetic operation, the Ingress axis after a L instruction, etc.).
B	Bell	B	Ring the bell to get the attention of the engine attendant.
H	Halt	H	Stop the engine. Stop the execution of the program.

.Adding 17 + 10 N1 17 N2 10 + L1 L2 S3 P B H .Quotient And Remainder N1 10000 N2 43 / L1 L2 S3' P S4 P B H .Count Down Timer N0 10 N1 1 L0 P - L0 L1 S0 CF?2 P CB+6 B H .Multiplying 17 x 12 N1 17 N2 12 x L1 L2 S3 P B H .Calculating 5! N0 5 N1 1 N2 1 × L1 L0 S1 P - L0 L2 S0 L2 L0 CB?12 B H .Fibonacci series N0 0 .Constant zero N1 1 .Constant 1 N2 12 .Number of terms to compute N3 0 .Iteration count N5 0 .Previous term N6 1 .Current term N7 0 .Temporary for next term N8 0 .n−2 term for ratio .Loop .temp = current + previous + L6 P L5 S7 .n−2 = previous L5 L0 S8 .previous = next L6 L0 S5 .current = temp L7 L0 S6 .Increment iteration count + L3 L1 S3 .Check if number of iterations reached − L3 L2 CB?28 B H .Note-G Algorithm .An algorithm to calculate Bernoulli Number B7 (-1/30) .Based on Ada Lovelace's Note - G algorithm .1 N1 1 N2 2 N3 4 .Bernoulli numbers shifted by 12 digits N21 166666666667 .B1 N22 -33333333333 .B3 N23 23809523809 .B5 N24 0 .B7 X L2 L3 S4 S5 S6 .2 - Z4 L1 S4 .3 + Z5 L1 S5 .4 / Z4 <12 Z5 S11' .5 Z11 L2 S11' .6 - Z13 Z11 S13 .7 L3 L1 S10 .8 + L2 Z7 S7 .9 / L6 <12 L7 S11' .10 X L21 L11 S12 L12 >12 L1 S12 .11 + Z12 Z13 S13 .12 - Z10 L1 S10 .13 - Z6 L1 S6 .14 + L1 Z7 S7 .15 / L6 <12 L7 S8' .16 X Z8 Z11 S11 L11 >12 L1 S11 .17 - Z6 L1 S6 .18 + L1 Z7 S7 .19 / L6 <12 L7 S9' .20 X Z9 Z11 S11 L11 >12 L1 S11 .21 X L22 L11 S12 L12 >12 L1 S12 .22 + Z12 Z13 S13 .23 - Z10 L1 S10 .13 -REPEAT- - Z6 L1 S6 .14 + L1 Z7 S7 .15 / L6 <12 L7 S8' .16 X Z8 Z11 S11 L11 >12 L1 S11 .17 - Z6 L1 S6 .18 + L1 Z7 S7 .19 / L6 <12 L7 S9' .20 X Z9 Z11 S11 L11 >12 L1 S11 .21 X L23 L11 S12 L12 >12 L1 S12 .22 + Z12 Z13 S13 .23 - Z10 L1 S10 .24 - Z24 L13 S24 P .25 L1 Z3 S3 Z6 Z7 B H