Manual / Guide · 1963
Digi-Comp I Instruction Manual (1963)
The original Digi-Comp I manual: operating the machine, coding sheets and every experiment.
Manual / Guide · 1963
The original Digi-Comp I manual: operating the machine, coding sheets and every experiment.
TABLE OF CONTENTS IN TRODU CTION PAG E How man discovered more and more CHA P T E R I - O P E R AT I N G DI G I-CO M P complex machines. 1 @ Che ck Out Making sure DIGI-COMP is working properly. 2 Check Out: Expe r i ment 1 See your DIGI-COMP working like a digital computer. 4 The Codi ng Sheet A short cut to prepare experiments for DIGI-COMP. 5 Expe ri m ent 2: Fi nal C ount Down Try this Space Ship Problem. 8 You may skip to Chapter III if you want to try more experiments. CHA PTER II - THE LA N G U A G E O F CO M P U T E RS 9 B i nary Sy stem A new but simpler language. 9 B i nary Addi t i on Add the lazy man's way. 11 B i nary System i n Com puter s Computers use binary. 12 Programm i n g How you can communicate with DIGI-COMP. C HA PT E R Ill - E X P E RIM E N TS 12 15 Expe r i ment 3: Automatic Elevator 15 Expe ri ment 4: Bank Lock 16 Expe ri ment 5: Sequential Bank Lock 16 Exper i ment 6: Ho-Hum 17 Expe r i ment 7: Space Ship Check Out 18 Expe r i ment 8: Guess The Number 19 Expe r i ment 9: Space Capsuie Re-Entry 20 Exper i ment 10: Binary Counter 21 Th e "OR" Ope ra ti on Some More About Programming 21 Expe r i ment 11 : Game of NIM 23 Expe r i ment 12: Binary Number Comparator 24 Expe r i ment 13: Binary Adder 25 Experi ment 14: Binary Subtraction 26 Expe r i ment 1 5: Binary Multiplication 27 Problems For You To Program 28 © 1963, E.S.R., I N C. A L L R I G H T S RESER VED N O T T O B E C O P I ED I N W H O L E OR I N P A R T INTRODUCTION You now own a DIGITAL COMPUTER! What can DIGI-COMP I do? What does it mean to us that today our civilization is ad vanced enough to design and build complex machines such as digital computers? For many years man has tried to substitute a machine for man's brain or to put it another way to ''AUTOMATE" the ' machine. The idea of a machine that thinks has always fas cinated man. ROBOTS have long been a fp.vo�ite character of science fiction writers. The science fiction robot is generally thought of as a machine built in the shape of a man whose purpose is to serve man. It cannot develop new and original thoughts - IT CAN ONLY DO WHAT ITS MASTER INSTRUCTS IT TO DO., Today we have real robots. These robots do not look like the tin man in the Wizard of Oz - in fact they do not look like men at ·all, but they do the work of men and usually do it much bet ter. They can be very simple - such as the thermostat in your home, an automatic elevator, traffic signals, automatic gear shift, automatic toll collectors and many other automatic devices which you see every day. There are also the complex robots that guide our satellites, translate languages, figure payroll checks, solve complex mathematical problems - in fact, th�y ·will do almost anything we want them to do. These complex automatic machines are not called robots - THEY ARE ·CALLED COMPUTERS. - WHAT IS A COMPUTER? The word COMPUTER can mean. several things. If you have ever counted on your fingers YOU could be called a DIGITAL COMPUTER. The word digit means finger (or toe) and a com puter is someone or something that does .number work. fr.-L\ .I. \ �d Large digital computers are sometimes called "THINKING MACHINES" . This is wrong. NO MACHINE CAN THINK - it can only do what it is told to do. But it can add, subtract, . multiply and divide very, very fast. Computers range in size from your DIGI-COMP I to small desk size adding machines to the "ELECTRONIC BRAINS" which can occupy an entire room and even in some cases an entire buildiil,g. To give you an idea of the usefulness of these amaz ing machines, some computers can do number or mathematical problems in minutes or hours that would take more than your -' _: . _· - ... ' .... -. lifetime to solve with a paper and pencil. So you can easily ·see that without these complex machines we would still be a long . . way off frorri launching astronauts into space, designing space craft for moon flights, being able to accurately predict the path of hurricanes, storms and tornadoes or controlling the automatic telephone dialing system, and many, many other things that affect our daily living. Your DIGI-COMP I i� obviously not the size of a giant "electronic brain". lt is a mechanical :equivalent of an elec . tronic digital computer. With DIGI-COMP -�I you can PLAY GAMES, SOLVE RIDDLES, and DO ARITHMETIC in the same way as you would on a large digital computer. DIGI-COMP I is the first real BINARY COMPUTER which works MECHANICALLY the same way as giant electronic digital computers which work electrically. YOUR DIGI-COMP can be considered as a small version of an actual computer - in fact, with the addition of many more parts, DIGI-COMP could solve very large problems just as an electronic digital computer does. The mil.in differenc,e is that since DIGI-COMP is mechanical it would'be much slower and larger than an electronic computer. But the important thing is that EVERYTHING YOU LEARN ON DfGI-COMP CAN BE USED ON LARGE. ELECTRONIC DIGITAL COMPUTERS. -�\- - -��-·,1_:_.!/- � .L;- 1 O P E RA T I N G You now have a completely assembled digital computer. Before putting your first experiment on DIGI-COMP let us make sure all the parts in the computer are working properly. This is called the CHECK OUT. STEP 1 - See Figure 1. Move the CLOCK all the way "OUT" (to the right). STEP 2 - See Figure 1. Make sure all LOGIC RODS are in the "ACTIVE" position (turn to the right). STEP 3 - See Figure 1. Slowly move CLOCK all the way "IN" (to the left) and th�n all the way "OUT" (to the right). THIS IS CALLED "C YC LING" THE CLOCK. C YC LE the clock about 5 times. Each time you move the clock "in" then "out" a "CYCLE" is completed. STEP 4 - Slowly move the clock so that the logic rods are in this position.----�-� STEP 5 - Carefully look down at the logic rods to see if they are ALL touching the groove of the CLOCK PLANE. ----,� If all logic rods touch, go to Step 6. If any logic rod is NOT touching the groove of the clock plane: ---a. Make sure the logic rod is in the top and bottom holes. b. Make sure it moves EASILY. c. If it still doesn't touch, replace the rubber band by removing the STOP PIN and TOP PLATE. (Reassemble TOP PLATE and STOP PIN). With CLOCK pulled OUT, clock rods sh uld look like this. / , ==nDdl� STEP 6 - Slowly move the clock all the way out (to the right). Take the computer by the base and turn it around. Look at the CLOCK RODS in the BACK of the computer. See if they are ALL touching the inner edge of the clock plane. If they all tcuch, go to Step 7. If one does not touch it is not through the clock planes correctly. Take it out and put it in right. (Step 12 of the Assembly Instructions). STEP 7 - With the FRONT of the computer facing you, slowly move the clock all the way in (to the left). Look at the CLOCK RODS in the BACK of the computer. They should ALL be as in Figure 2. If they are all right go to the Check Out Problem. If one is not right: a. Check to see if the logic rods are all ·in the slots of the sliders (see Step 9 of Assembly Instructions, and Figure 1). b. Check to see if the "clock rod is in the slot of the slider (see Step 12 of Assembly Instructions, and Figure 2). c. Check to see if BOTH planes 6 and 7 are moving all the way (if not see Step 6 of Assembly Instructions, and Figure 2). You are now ready to put a "CHECK OUT" prob lem into DIGI-COMP. A check out problem is one to which you know the answer. By checking this answer against DIGI-COMP'S answer you can determine if the computer is operating properly. 2 FIGURE 1 FRONT OF COMPUT ER D. Make sure logic rods are in slots. C. Manual Input Tabs. O�GICOMP I -A�·.�. B 1 o 0 c 1 .¥ "' A. B. Clock shown in NEUTRAL position. FIGURE 2 BACK OF COMPUTER F. Make sure CLOCK RODS are in slots. �IT clock rods G. If both Planes 6 and 7 are not moving all the way, make sure wire crank is in BOTH slots as shown. 3 Clock CHECK O U T P R O B L E M First you must "PROGRAM " DIGI-COMP. To PROGRAM DIGI COMP MEANS TO PUT LOGIC TUBES AND CLOCK TUBES ON THE COMPUTER. STEP 1 -Move CLOCK all the way out (to the right). STEP 2 -Move all logic rods to the INACTNE POSITION (Turn to the left). Position 5 STEP 3 -With the front of DIGI-COMP facing you FIRMLY put logic tubes (short tubes) onto: "T" " F" "F" "T" "F" "T" peg of peg o f peg o f peg of peg of peg o f the the the the the the A flip-flop A flip-flop B flip-flop B flip-flop C flip-flop C flip-flop at Position 5 . a t Position 6 . at Position 1, at Position 2. at Position 3 . a t Position 4 . STEP 4 -Move all logic rods t o the ACTIVE POSITION (turn to the right). STEP 5 - FRONT With the BACK OF DIGI-COMP facing you FIRMLY put clock tubes (long tubes) onto: Positions 1 and 2 of the A flip-flop. Positions 3 and 4 of the B flip-flop. Positions 5 and 6 of the C flip-flop. DIGI-COMP is now PROGRAMMED. To Ope rate DIGI-C OM P : STEP 1 - With the front of. the computer facing you make sure the clock is all the way out (to the right). With the Manual Input Tabs SLOWLY move the flip-flops " in " (left) and "out" (right), one at a time, to see if any of the logic tubes are hitting the logic rods. If a logic tube hits a logic rod, push it on firmly. If it still hits the logic rod replace it. "A" STEP 2 - With the Manual Input Tabs move all flip-flops to the right (see g in the Read-Out). 0 STEP 3 -Slowly cycle the clock a number of times. TO CYCLE THE CLOCK SLOWLY MOVE IT ALL THE WAY IN (LEFT) AND OUT (RIGHT). You should see in the Read Out: BACK Before the first clock cycle 0 0 0 After the first clock cycle 0 0 1 After the second clock cycle 0 1 1 After the third clock cycle After the fourth clock cycle 1 1 0 After the fifth clock cycle 1 0 0 After the sixth clock cycle 0 0 0 As you continue to cycle the clock the sequence will repeat. If you see this sequence, DIGI-COMP IS WORKING AS A DIGITAL COMPUTER. If you do not see this sequence go to Step 1 of Check Out Problem. What is DIGI-COMP doing? 4 CHE C K O U T P RO B L E M C O N TI N U E D The experiment you have just completed with DIGI-COMP is a typical computer operation known as " COUNTING BY SHIFT ING". " Counting by shifting " means that whatever is in the Read Out of a flip-flop is transferred (shifted) to the flip-flop above AND the oppqsite of whaf is in the Read Out of the top flip-flop is transferred (shifted) into the bottom flip-flop. You should see the following sequence: A B c CODIN G SHE E T Instead of saying i n words where t o put the logic tubes and clock tubes, from now on we will use a "CODING SHEET ". A coding sheet is used for all electronic digital computers to make it easier for the man to prepare problems· for the computer. DIGI-COMP'S coding sheet will be used for the same purpose. The coding sheet looks like DIGI-COMP to make it easy to use. 4 2 T � F 1 T F 2 T F 3 T F 5 4 F T 6 5 T F 6 A B c A / The numbers at the top of the <;:oding sheet can be seen 9n the Top Plate. These are the POSITIONS. ..., 1 ® ';' ..r' 2 3 • 1 ., a.at 4 s TOP PLATE ( � s �' ' ' ) FRONT The numbers in FRONT of the TOP PLATE are the POSITIONS of the Logic Rods. The numbers in BACK on the TOP PLATE are the POSITIONS of the Clock Rods. For example, find LOGIC ROD �OSITIONS 1 and 6 on your computer. Now - find the CLOCK ROD POSITIONS 2 and 5 on DIGI-COMP (look at Figures 1 and 2 for the answer). B ACK Each POSITION (number) on the CODING SHEET has under it a T and F. These correspond to the six sets of T and F PEGS on EACH Flip-Flop. If you look at DIGI-COMP you will see that under each of the 6 POSITIONS marked on the Front of the Top Plate there is a set of PEGS marked T and F on each Flip Flop. ·5 FRONT FIGURE 3 "T" PEG OF FLIP-FLOP "B" / \ .... .... . . .... 1\. ... . • � POSITION 3 .. . � l:a .. • � IP -FLOPS \ B� ' A \c � ' - - - - - \ - l I FIGURE 3B BACK ... "C " FLIP-FLOP c ,. . .. • ... � • 1111 • • .. . 1:::1 � � r;:::� \ 7 lLU I \._\ n 1\ \ - ,... '-" ' - -- �. \ \ 6 " PEG 6 -. \_ .- "3" PEG I COD � G S HE E T C O N T I N U E D For example, find theA_ T PEG of the B Flip-Flop at Position 3 on DIGI-COMP. On the BACK of each Flip-Flop there are six PEGS marked 1 , 2, 3, 4, 5, 6. These pegs also correspond to the six positions marked ori the TOP PLATE in BACK. On the Coding Sheet these PEGS are represented by the numbers to the right of the T-F UNDER EACH POSITION at the TOP of the coding sheet. For example, find the 3 and 6 PEGS of the C Flip-Flop on your computer (See Figure 3A and 3 B for answers). '+ t+ tt You may have noticed on the Top Plate next to the numbers in back, the words RESET and SET. This is to remind you that Clock Rod Positions 2, 4 and 6 must be used to SET a flip-flop and Clock Rod Positions 1, 3 and 5 to RESET a flip-flop. SET means to change a flip-flop from "0" to "1" (in the Read Out). (The Flip-Flop . moves to the left for a SET). RESET means to change a Flip-Flop from "1" to "0" (in the Read Out). (The, Flip-Flop moves to the right for a RESET). If a flip-flop has a CLOCK TUBE on the PEG in CLOCK ROD POSITIONS 1, 3 or 5 it will RESET when the clock is cycled. If a Flip-Flop has a CLOCK TUBE on the PEG in CLOCK ROD POSITIONS 2, 4 or 6 it will SET when the clock is cycled. Slowly cycle your computer and watch how this works in the back. Notice. when a logic rod moves in it pushes the SLIDER. When the slider moves it pushes the clock rod out so that the clock rod is caught by the clock plane. Now that you understand how the coding sheet corresponds to the various parts of the COMPUTER let 's see how to use it. The coding sheet is FILLED OUT BY MARKING IT with the following symbols: L -Firmly put a LOGIC TUBE (Short Tube) onto the indicated PEG of the Flip-Flop at the Position marked. C - Firmly put a CLOCK TUBE (long tube) onto the PEG of the Flip-Flop at the Position marked. (OUT) -Move the LOGIC ROD in this Position to "INACTIVE" (turn to the left). Your computer now has the CHECK OUT experiment programmed on it. Try FILLING OUT The Coding Sheet below for the CHECK OUT Experiment on Page 4. For example, on page 4 it says PUT LOGIC T UBES into: "T" PEG of the A Flip-Flop at Position 5. You would mar� an L as shown on the Coding Sheet. Also on page 4 it says PUT CLOCK TUBES into: Positions 1 and 1 of the A flip-flop. You would mark C's where shown on the Coding Sheet. 2 T F A 1 T F 2 c c 3 ! F 3 4 T F 4 5 6 T F 5 T F 6 L 8 c (Go to Page 28 to check your answer.) 7 Let's program another experiment using the Coding Sheet. EXPE R I M E N T 2 F I N A L C O U N T DOW N ·- Your DIGI-COMP will automatically signal the BLAST OFF of a space ship from Cape Canaveral at the right time. To Opera te DIGI-COM P : STEP 1 -Put Front Panel Card I in place. STEP 2 - Make sure CLOCK is all the way to the right. STEP 3 - Remove ALL logic and clock tubes. STEP 4 - "PROGRAM" (Put in Logic and Clock T ubes) DIGI-COMP according to the coding sheet. (Put logic tubes on first then put clock tubes in place). 2 T A L F 1 T F 2 T L C c B F F 3· T F 4 - ,---t-- L L L c L C L L L L 6 5 4 3 T c L F 5 c T 6 L c STEP 5 -Manually (with the MANUAL INPUT TABS) move all flip-flops to the LEFT so that you see i in the 1 Read Out. STEP 6 - Cycle the clock slowly until Read Out. 0 0 0 appears in the THIS IS THE "BLAST OFF" SIGNAL. DIGI-COMP has counted 7 clock cycles starting at 0 i1 and end"mg at g . If you want to read about the LANGUAGE OF COMPUTERS go to the next chapter. If you want to try more experiments now go I to page 15 . a / I cuf;t.t�ta•f.GI·'Ii·M•a••;g$1 Bin a ry System To understand DIGI:..coMP you must learn the LANGUAGE OF COMPUT�RS. If you are to tell DIGI-COMP what to do and if you are to understand the computer's answers, you must use a language you and DIGI-COMP both know. L uckily this language is very simple - much easier to learn than it was to learn decimal numbers. THIS LANGUAGE MAKES THE OPERATION OF DIGITAL COMPUTERS P OSSIBLE. The computer's language is know n as the "BIN ARY SYSTEM". BINARY NUMBERS use only two symbols, 0 and 1, rather than the ten decimal numbers (0, 1, 2, 3, -4, 5, 6, 7, 8, 9). �� -r1 Since the binary system has only two symbols, these symbols can be used to mean many things. They may mean ON-OFF, TRUE-FALSE, YES-NO or any other kind of two way opera tion. Therefore, the binary system can be used in many devices - lights ON or OFF or, as in DIGI-COMP, two positions of a flip-flop -LEFT and RIGHT. You have learned that in decimal numbers 683 actually means: 6 one hundreds + 8 tens + 3 ones. Then 683 can be written as: 683 60 0 + 80 + 3 + (8 X 10) + (3 X 1) or 683 6 X 100) or 683 (6 X 10 � 10) + (8 X 10) + (3 X 1) + (8 X 101) + (3 X 10°) Or 683 = (6 X 102) = = = (Any number raised to the power of zero is equal to one, thus 10° = 1.) In the number 683 the digit 6 is in the "hundreds'' position the digit 8 is in the "tens" position -and the digit 3 is in the "ones" or "unit" position. · In other words we may say that each digit in any decimal number is a different power of ten depending on the position of the digit within the number. What will each position in the binary number system mean? In the binary system we have only two symbols (0 and 1). There fore, EACH POSITION REPRESENTS A DIFFERENT POWER OF. TWO (2). That is, they are 2°, 21, 22, 23, and so on. An example of a binary number is: 110 This number is read: "ONE, ONE, ZERO." The meaning of this binary number can be written as in the following example: · 110 = (1 X 22) + (1 X 21) + (0 X 2 °) or 110 = (1 x 2 x 2) + (1 x 2) Or 110 = (1 X 4) + (1 X 2) + (0 x 1) + (0 X 1) Instead of saying a number has "digits" as in the decimal system we say a binary number has "bits ". 9 B I N ARY SYST E M C O N T I N U E D In the binary system the FIRST position AT THE RIGHT is called the "ones bit" (2°), the SECOND position from the right is the "twos bit" (21), the THIRD position from the right the "fours bit" (2 2 ) , the fourth position the "eights bit" (2 3) and so forth. You can TRANSLATE this binary number to a decimal number. 1 10= (1 X 4) + (1 X 2) + (0 X 1) / 1 "" (4's bit) (2's 4 +2 t t) (1's bit) +0 =6 As you see, translating between the binary and decimal number systems is easy. The chart will help you translate between the decimal and binary number systems when you use DIGI-COMP. TRA N S LA T I O N CHART B IN A RY SYSTEM FOURS BIT 4 TWOS BIT . ONES BIT 2 DECIMAL EQU IV ALE NT ==== 0::!: 0 0 1 = 0 0 2= 0 3 = 0 4 = 5 = 0 0 0 0 0 0 6= 7= Using the Translation Chart try translating these DECIMAL numbers to BINARY: 6= 4 � 3= Also, try translating these BINARY numbers to DECIMAL: 101 = 001 = 111 = (To check your answers go to page 28.) 10 1 D '11 ) B INARY ADDIT ION It is very easy to add two binary numbers. THERE ARE ONLY FIVE RULES TO REMEMBER: RULE 1 0 + 0=0 RULE 2 0 + 1 =1 RULE 3 1 + 0=1 RULE 4 1 + 1 = 0 with a " 1 " carry (read: one, zero; 10) RULE 5 1 + 1 + 1 = 1 with a " 1 " carry (read: one, one; 1 1 ) Compare this with the decimal addition table! A few examples are: 2 + 3=5 1 + 0=1 . 3 + 6=9 8 + 4 =2 with a " 1 " carry (1 2) 9 + 7=6 with a " 1 " carry (16). In fact, there are 65 addition rules in the decimal system! As you know when two decimal numbers are added, the "carry" from one column is added to the digits of the next column. For example: 1 11 976 + 425 1401 Exactly the same thing is done in the binary system. For example. carry 1 1 11 1 1 01 1 + 1 01 10 1 10001 (Can you figure out the decimal equivalent of these numbers?) (See page 2 8 for the answer .) the binary system the "CARRIES" FROM ONE COLUMN ARE ADDED TO THE "BITS" OF THE NEXT COLUMN. In Although the binary system is very simple, it requires many binary bits to represent a number. For example: The decimal number 50 (only 2 decimal digits) is 1 1 0010 in binary (6 binary bits). This is one of the reasons that although digital computers can be made of v ery simple parts, many thousands of these parts are needed. 1 - NOTE that wh en more than three ones are added, there will be. more than one carry. As an example: carry 11 (1) (1) (1) (1) 1 0 1 + 1 1 1 1 1 101 0 or 3 1 3 + 3 10 B IN A RY S Y ST E M IN C O M P U T E RS As we said before, the binary system can be adapted to many uses, including YES-NO or T RUE- FALSE representation. Thus the modern computer can make simple decisions about complicated matters using the binary language. The Computer need only decide True or Fa l s e each time a question is asked. As an example, before a space ship can be launched, a digital computer is used to make the decision whe ther everything fs A-0-K. -It can do this by looking at thousands of parts of the'space ship and decide whether they are operating properly. The computer does this by determining if the part is giving the correct answer to the "question" being asked of it. If the answer does not compare with what it should be then the answer is Fals e; if it does compare, then the answer is Tru e . There are so many o f these True-False decisions t o be made in such a short period of time, that the computer must make thou sands of such decisions each second. Your DIGI-COMP uses True-Fa l s e as well as binary numbers (0 and 1 in the Read Out) as you will see in the next section on PROGRAMMING. P R O G R A M M IN G Now that you understand the computer's language, let us see how DIGI-COMP uses the language. As we know, a computer has no brain, but it can work very complex problems, if it is to ld how to work them step-by-step. THIS IS CALLED PRO GRAMMING. You have been programming all your life! Whenever you tell someone to do something, or how to do it, you are programming. Your mother tells you it is raining outdoors. If you go .outdoors then: A. If you wear your rubbers AND B. If you wear your raincoat THEN C. You will not get wet. This is a program. Another way of stating this is: STATEMENT A - If it is true that you wear your rubbers AND STATEMENT B - If it is true that you wear your raincoat THEN STATEMENT C - It is true that you won't get wet. Now, let us forget about rain, raincoats, and rubbers for a moment. Just think about L�e connection between Statements A, B, and C. You can easily see that: 1. If A is True AND If B is Tru e THEN C is True. It is important to understand that C is true ON LY when A AN D B are both tru e . You can also reason: 2. If A is false AND If B is tru e THEN C is fa ls e. Also, you may say that: 3. If A is true AND If B is false THEN C is fals e . Also, 4. If A is false AND If B is fa ls e THEN C is fa Is e . 12 PROGRAMMING CONTINUED �In order to make th.ings simpler, let us introduce some 'Symbol� represert�t words or state�ents. We, will now substitQt�: for' Statement 'A. if it is' t ru �. A �· ':' ; " :..:.' "· ;::;r• - {0r Statehle�(.G �i�, i,t is t:��· " A�,B=C If A is true and B is }� · B :c we A. = True A = �Fals e B = Ttu "e = _, � P RO G RA M M I N G C O N TIN U E D L et us program DIGI-COMP for the first set of statements: 1. A · B = C. STEP 1 Remove all the logic tubes from the front and all the clock tubes from the back of your computer. - STEP 2 Put logic and clock tubes on according to the coding sheet. - 1 T F A L B L 2 T F 3 6 5 4 3 2 T F T F 4 T F 6 T F 5 c c STEP 3 right. - Move the clock all the way out to the s'TEP 4 Move the C flip-flop all the way out to the right so that you read a " 0" in its read-out. - STEP 5 With the Manual Input Tabs set the A and B flip-flops to the left so that you read "1" in their read-outs. - STEP 6 - Cycle the clock once. A "1" should appear in the C read�out. Try any other combination of A and B; for example: A = 1 and B = 0 (C will NOT become "1"). WE HAVE JUST PROGRAMMED THE " AND" OPERATION FOR THE 1 st SET OF STATEMENTS ON DIGI-COMP. This operation is represented on the computer by the logic rod in Position 2. Logic rod 2 will go " in" on ly when flip-flops A AND B are both "1". If either one of them is "0", logic rod 2 will be blocked from moving " in" by the logic tubes. (Set A 1, B 0 and watch the logic rod being blocked from moving in as you slowly cycle the clock. ) = = Now let us program the second set of statements on DIGI-COMP (A B = C). In thi$ case, if A 0 (A is fa l s e ) AND B 1 (B is tr ue ) then C must be made "0" when the clock is cycled. This means C must be res et when A = 0 and B 1. · = = = At POSITION 1 (reset) put a logic tube into the A flip-flop on the "F" peg (A is fa ls .e) AND a logic tube on the B flip-flop on the " T" peg (B is t ru e ). Put a clock plug on the C flip-flop (on the back) at Position " 1 " (reset). This is the program for the second set of statements. You can fill out a coding sheet for this program as shown below. 1 T F c T F 3 2 T F 4 3 T F 5 4 T F 6 5 T F 6 L A B 2 1 L c Try this second set of statements on your computer. STEP 1 - Move clock all the way to the right. ST EP 2 With the Manual Input Tabs set "0" in A and "1 H in B. - STEP 3 - Cycle the clock - C should have a "0" in its Read-Out. Try PROGRAMMING Statements 3 and 4 for DIGI-COMP. (See Page 28 if you have trouble. ) YOU HAVE JUST PROGRAMMED YOUR COM PUTER. 14 CHAPTER Ill - EXPERIMENTS Now you are ready to program the different problems, riddles and games that are in this chapter. There are real experiments showing how automation is used; for amusement there are logical riddles and games. At the end of the ·chapter, binary arithmetic and the different operating parts of large digital computing machines are discussed and demonstrated using DIGI-COMP. In the experiments that follow the program has been worked out. for you. If you would like to try programming an experiment yourself, go to Page 28. You have a set of FRONT PANEL CARDS included with the Instruction Manual. Each experiment uses one of these cards. You must put the correct card for each experiment in the slots on the Front Panel. The card should be bent on dotted line to hold it in place. IN ALL EXPERIMENTS MAKE SURE LOGIC TUBES AND CLOCK TUBES ARE ONLY IN THE POSITIONS INDICATED BY THE CODING SHEET. , EXPERIMENT 3 - AUTOMAT IC ELEVATOR The automatic elevator is a common example of automation which uses MEMORY. A simple automatic elevator is the two ·floor elevator. The automatic system is required to REMEMBER at which of the two floors it has stopped. In the elevator there are two buttons, one to tell the elevator to go to the 1st floor and the second to tell it to go to the 2nd floor. On each floor there is a button (CALL button) which you can push to tell the elevator to come to your floor. 1- ,-I I -+- Imagine the CALL buttoll' on the 1 st floor is the same as the button in the elevator directing it to the 1st floor. Also, the 2nd floor CALL button is the same as the 2 nd floor button in the elevator. Put FRONT PANEL CARD II into place. On this card there is marked " UP-DOWN" . If the bottom flip-flop is at "1'', the elevator is directed to the 2nd floor, and if it is at " 0", to the 1st floor. (Look at the Read Out next to UP-DOWN. ) The floor at which the elevator is located is indicated by_ a "1" in the Read Out by the floor. DIGI-COMP can be used to show how this elevator works. PROGRAM DIGI-COMP according to the coding sheet. 2 T F A 1 T F c T F 3 T F c L 6 5 4 T F 5 T F 6 c B c 4 3 2 L L c L To operate DIGI-COM P: STEP 1 -Make sure logic and clock tubes are ONLY in the positions indicated on the coding sheet. STEP 2 -Make sure all LOGIC RODS are in the ACTIVE POSITION (turned to the right) and the CLOCK is all the way out (to the right). STEP 3 -Manually set the "up-down" flip-flop to "1" if you want to go up or to "0" if you want to go down. STEP 4 - Cycle the clock. 15 E X P E R I M E N T 4 - B A N K LOCK Each morning the president of the MONEY bank has to open the bank vault. It is a combination lock using binary numbers. This morning the president was surprised to find he couldn't remember the combination. Can you open the vault for him? Program DIGI-COMP as in the coding sheet below : T A L B L c L 1 F c 2 T F L L L T c I 3 F I\ T F 4 L L II c T 5 I' ·f 6 L I<DU ' L 6 F T I I<DU ' 5 4 3 2 L II L c STEP 1 -Use Front Panel Card I. STEP 2 - You guess the binary combination and manually set the combination into the three flip-flops. STEP 3 -Cycle the clock ONCE� If you see � 1 in the Read-Out, you have successfully opened the vault! If you do not see 1 � try again! What is your chance of opening the vault on the first try? E X P E R I M E N T 5- S E Q U E N T I A L B A N K LOCK To make it more difficult for anyone but the president of the bank to open the vault, a new type lock was installed. This lock requires two binary numbers in a particular order to open it. Program DIGI-COMP according to the coding sheet. 2 1 T F A 2 L c ' I B IOU c ' II 4 3 T F T F I L . ou L ' 3 T ' F !/ T F T F 5 I\ L L 6 5 4 c L )U L 6 L II L c To operate DIGI-COM P : STEP 1 -Use Front Panel Card I. STEP 2 -Make sure clock is all the way to the right. 0 STEP 3 -Manually move all flip-flops to the ri gh t .(See g in the Read-Out. ) STEP 4 - Guess the first binary number �.�,�or � and manually enter it in the A and B flip-flops- STEP 5 -Cycle the clock ONCE. If the C flip-flop goes to "1" then the number you entered was correct and go to step 6. If j t stays at "0" try Steps 4 and 5 again. _$TEP 6 -Guess the second binary number �. � o r � not : and manually enter it in flip-flops A and B. . 1 STEP 7 - Cycle the clock ONCE. If you see � in the Read-Out, you have opened the vault. If not, try Steps 5 and 6 again. This time what is your chance of opening the vault the first try? 16 · E X P E RIM E N T 7 - S P A C E S HIP CHECK O U T ) ( A �ob For A n Astronaut) This is the last moment before "blast off" . It is time for you to make sure all the important parts ("systems") of your space ship are operating properly. You must now go through the final "check-out procedure" . If anything is wrong the launching will be canceled. There are three �ystems to be checked: 1. Oxygen system 2. Space-Ship controls 3. Radio To check these systems the following questions are asked. They must be answered correctly to avoid a cancellation of the launch. 1. How much oxygen is flowing? 2. Is the "control stick" in the correct position? 3. To what frequency is your'-radio turned? All 3 answers have a numerical v alue. These values will be checked one at a time with the values stored in DIGI-COMP. If they check correctly the computer will indicate that the system is "A-O. K." If not, the computer will indicate a mal function (not working properly). Program DIGI-COMP according to the coding sheet: T F 1 A F L 2 c T F 3 ou L L c ' L L F 4 L c L T 5 F II I L L 8 T 6 5 4 3 2 T )U c \ T F 6 L c L L 11 To oper te DIGI-COM P : STEP 1 -Use Front Panel Card I. STEP 2 -Move all logic rods to INACTIVE (turn to the left) except Nos. 2 and 3. STEP 3 -Guess how much oxygen is flowing and man ually move the flip-flops to the numerical value (anything from 000 to 111). in STEP 4 -Cycle the clock ONCE. If the result is l the Read-Out, the�1 the system is operating "A-O. K.". If the result has a " 0" ANY PLACE, then the system is NOT operating correctly. Move the flip-flops and cycle the 1 clock until you get the "A-O. K. " signal, � . STEP 5 - Repeat Steps 3 and 4 for the next two questions. For the second question move logic rod num ber 4 to the ACTIVE POSlTION (turn to the right). For the third question move logic rod number 6 to the right. When all three systems are "A-O.K." you are ready for your interplanetary voyage. 18 EXPERIMENT 8 - 11G U E S S THE N U M B E R" (A Logical Riddle) Here is a logical riddle to test your reasoning powers. Have a friend choose any number ·between 0 and 7, (0, 1, 2, 3, 4, 5, 6, 7). You are to find the number he chose from his answers to three questions. He will answer Yes or No to each question. QUESTION 1: Is the number even? QUESTION 2: Is the number 0, 1, 2 or 3? QUESTION 3 : Add 10 (ten) to the number and divide the result by 6; is the remainder 0, 1, 2 or 3? (For example, if the number is 5, then 5 + 10 15 and 15 divided by 6 is 2 plus a remainder of 3. The answer to the state ment would be Yes . If the number is 7, then 7 + 10 17 and 17 divided by 6 is 2 plus a remainder of 5. The. answer would be No.) = = Now try it: STEP 1 - Put Front Panel Card IV in place. STEP 2 -Program DIGI-COMP according to the coding sheet. 2 T A 8 c L F 1 c T 4 3 F 2 L c T F L 3 T c L 4 T L c L L 6 5 F L F 5 T F 6 L c L c STEP 3 - Make sure clock is all the way out (to the right). STEP 4 -With the Manual Input Tab enter the answers to the three questions into the flip-flop indi cated by the Front Panel. . Enter a "1" if the answer was YES. Enter a "0" if the answer was NO. STEP 5 -Cycle the clock ONCE. The Read-Out will have the number your friend chose in the Binary System. 19 EXPE R I M E N T 9 - S PA C E C A P S U L E R E - E N T�V Augie, the Astronaut, can re-enter the earth's atmosphere by p.1shing his Re-entry buttons in the correct sequence (order). '). Luckily, his space ship was designed so that if he made a mis take and pushed the WRONG sequence, nothing would happen. But then he must try ALL over again. Can you help Augie re.:.enter without making a mistake? Program DIGI-COMP as in the coding sheet. A B c L 1 T F L c L 2 T F 4 c L C L L T F 5 T F PUT I 6 I\ \ L L c L L T F 3 6 5 4 3 2 T F I<�U ' II TO O P E RA T E D I G I - CO M P STEP 1 -Use Front Panel Card V. STEP 2 -Make sure CLOCK is all the way out (to the right). Manually move all flip-flops to the RIGHT (see g in the Read-Out). 0 STEP 3 -Manually move the "r e-entry " button to either "0" or "1" . This is the choice of a bit in the sequence. STEP 4 - Cycle the clock ONCE. If the Re-Entry Button is in the CORRECT position the "Counter" will advance._ If you did NOT choose correctly the "Counter" will be reset to g . STEP 5 - Repeat steps 3 and 4 until the "Counter is at i. You have completed the re-entry for Augie's space ship success fully! Nothing can go wrong. (Notice that continued operation of the "Re-Entry Button" and cycling the clock will not change the "counter"). DIGI-COMP has automatically STOPPED. 20 EXPE R I M E N T 10 - B I N A RY C O U N T E R Binary counters are used in nearly all digital computers and automatic devic;es. There are many uses fot thes.e C04-nt�rs. They may count events or things . For example, a binary counter is used to count time s0 a computer will know when it has to do different op.eratipns. Binary c0unters can be used to autom().ticq.lly count candy bars being sent to the grocery store. · You have already counted down to "blast off" a s,pace ship. N:ow see. if you . can count ,up from 0 �6 7 in hinarx. ':fry wd�ing. the count £rom 000 to 1 1 I. · · To check yourself, use DIGI-COMP. Program DIGl-COMP �s in th e coding sheet., 2 T A F L 1 c 2 T ·F L C L L 8 c 4 5 1" F 4 , T F 3 T F 3 .A i::: L c ·' L C L 5· T · ·L '_ " ,, F 6 L c: ., - To operate DIGI-COM P: STEP 1 -Use Front Panel Card I. STEP 2 -Make sme clock is out. Enter " O"s into aU 3 · flip-flops. ' STEP 3 �eycle the. clock slowly a number of t imes. :Cook · ·at the Read-Out and watch DIGI-COMP count ! · - 110R" O P E RATIO N CO N TIN U E D To program this relationship on DIGI-COMP you will have to use the Double Slider. To put one of the double sliders on DIGI COMP: STEP 1 -Remove Stop Pin. STEP 2 -Remove Top Plate. STEP 3 - Move dock to Neutral (see Figure 1). STEP 4 - Remove at positions 1 and 2. Clock Rods STEP 5 -Remove Single Sliders at positions 1 and 2. STEP 6 - Insert Double Slider from the rear of the machine with the slots on Front of the Slider going around Logic Rods 1 and 2. STEP 7 - Make sure hole in Back of Slider is by Clock Rod position 2. If it is Not turn the slider over and put back in place as in Step 6 . ---- STEP 8 - Insert a Clock Rod into position 2 i n the back of DIGI-COMP. Make sure the Clock Rod goes through the hole in back of the Double Slider. STEP 9 - Put on Top Plate. STEP 10 - Put ·Stop Pin into place .. Now Program DIGI-COMP according to the Coding Sheet below. The symbol for the Double Slider is: I 0 Means the Double Slider goes into the two positions marked by this symbol. The hole in the back of the slider goes in the Clock Rod position marked bv the circle in the symbol. T A B c F 1 Of T F 2 T F 3 T F 4 T F L c 5 T F 11 I L 6 5 4 3 2 ,<!>U I<!>U I<!>U ' \ ' DOUBLE SLIDER 6 11 DU II IJ If you move A to "1" OR B to "1" then C will be set when the clock is cycled. DIGI-COMP is programmed for the "OR" operation. Now you may perform the �est of the experiments in the manual. 22 EXPE R I M E N T 1 1 G A M E OF N I M - NIM, an ancient game over 2 ,000 years old, was played by the wise men of the east. Two wise men sat at a table, each one having a pile of sto"nes by his side. The first wise man places either one or two stones in the center of the table. The second wise man adds 1 or 2 of his stones· to the stones in the center of the table. Each player takes a turn until there are 7 stones in the pile in the center of the table. The wise man who added the last stones to make the pile equal to 7 is the smartest of all wise men. DIGI-COMP claims to be very wise. Can you beat DIGI COMP? Either you, or the computer, may go first. To play NIM: STEP 1 -Place Front Panel Card I in position. STEP 2 -Program DIGI-COMP according to the coding sheet. T F A L B L c L 1 4 3 2 01 T F 2 T F 3 T F L c L c L L L 4 T F 5 T F c L c L L L L 6 5 L 6 c - STEP 3 -Make sure clock is all the way out. STEP 4 -Make sure all logic rods are turned to the right. STEP 5 -Make sure all flip-flops are all the way out (to the right). YOU OR DIGI-COMP MAY GO FIRST. If you go first: If the computer goes first: STEP 6 A - Add either 1 or 2 8 -Cycle the clock ONCE. to the number in the Read Out 0 0 0 If you want to add 1, move the flip-flops with the Manual Input Tabs until you see If the computer goes first: STEP 7 - b A -It is now DIGI-COMP'S 8 - It is your turn. Use the turn. Cycle the clock ONCE. translation chart to help you 0 translate the numbers in the which is 1, in the Read Out. Read Out to decimal. Add 1 or 2 to this number and translate If you want to add 2, move the flip-flops until you see � 0 back , to binary. Enter the binary number by moving the which is 2, in the Read Out. with flip-flops the Manual Input trabs until you see the number in the Read YOU MUST ADD EITHER 1 OR 2. TO THE NUMBER IN THE READ OUT ON YOUR TURN. STEP 8 -Repeat Steps 7-A and 7-8 (taking turns with the com puter) until you see i 1 in the Read Out. This is 7. THE FIRST TO MAKE THE PILE EQUAL TO 7 WINS! 23 Out. EXPE R I M ENT 1 2 - B I N A R Y N U M B E R C O M PARA T O R All electronic digital computers have the capability to determine whether two binary numbers are equal or not equal. On the basis of the answer (whether they are equal or not equal) the com puter can make decision s . It is this ability of the digital computer to decide what it will do next, based on the comparison of two binary numbers which makes people say the computer "thinks". The computer does not " think ' ' since someone programmed · it for each choice it co