ZXTape! 0Created with Ramsoft MakeTZXA.C.L. a  0:7:0: -3,4;"Active Computer Learning" 15,2;" 1984 EXPRESS MARKETING LTD" =7,12 ;"Volume A";9 ,11 ;"Program 2" (.11 ,6;"Loading- Please Wait" - 0 2"" )A.C.L. ggݽg 236099\,19 6:0:1: >7,14;"HOW A":9 ,9 ;"COMPUTER WORKS" 2:5,5;"":6,5;"":6,26;"":x=7 10 :x,5;"":x,26;"":x:11 ,5;"" 4:4,4;"":z=5 12 :z,4;"":z,27;"":z:12 ,4;"" 1:3,3;"":v=412 :v,3;"":v,28;"":v:13 ,3;"":0  9500%  :0 g4,2;"A computer works through 4 basic stages in the course of any operation." 9 ,2;"These are-":11 ,11 ;" ":12 ,11 ;" INPUT ":13 ,11 ;" " !6::a$=" Information is fed into the computer." " 9000(# # 9500% (u:4,9 ;" ":5,9 ;" PROCESSING ":6,9 ;" " -w:::a$=" The computer acts upon this information according to the rules laid down in the program." 2 9000(# 7 9500% ::a$=" Through the computer KEYBOARD." 9000(# 9500% ..KEY.PIC.. 0:0:7  s0:7:7,161:244,0:0,-145:-244,0:0,145 i7,120x:244,0:2,2;"S I N C L A I R":3,2;"zxspectrum" 8,2;"1 2 3 4 5 6 7 8 9 0":9 ,2;" " 11 ,3;" ":12 ,3;"Q W E R T Y U I O P" 14,2;" ":15,2;"A S D F G H J K L " 17,2;" ":18,2;" Z X C V B N M "  300, 1:6:0::4,9 ;" ":5,9 ;" PROCESSING ":6,9 ;" ":0  h'':a$=" Through a chip in the computer called the CENTRAL PROCESSING UNIT."  9000(# ***c.p.u.*** 5:64@,64@:104h,0:0,-32 :-104h,0:0,32 :64@,568:104h,0:64@,480:104h,0:64@,40(:104h,0  72H,64@:0,-32 :80P,64@:0,-32 :88X,64@:0,-32 :96`,64@:0,-32 :104h,64@:0,-32 :112p,64@:0,-32 :120x,64@:0,-32 128,64@:0,-32 :136,64@:0,-32 :144,64@:0,-32 :152,64@:0,-32 :160,64@:0,-32 "&0:15,12 ;"C.P.U." ' 9500% ,l:4,11 ;" ":5,11 ;" MEMORY ":6,11 ;" " 1D :::a$=" Through the MEMORY CHIPS." 6 9000(# ; ***ROM*** @103g,72H:0,-25:104h,72H:40(,0:0,-25:-41),0:13 ,13 ;"":14,13 ;"":15,13 ;"":14,14;"ROM" E103g,480:0,-8:-568,0:0,-8:33!,32 :40(,0:0,-17:-40(,0:0,17:18,5;"RAM" J144,480:0,-8:568,0:0,-8:175,32 :40(,0:0,-17:-40(,0:0,17:18,23;"RAM" O111o,480:0,-16:79O,32 :40(,0:0,-17:-40(,0:0,17:18,11 ;"RAM" T136,480:0,-16:127,32 :40(,0:0,-17:-40(,0:0,17:18,17;"RAM" Y 9500% ^l:4,11 ;" ":5,11 ;" OUTPUT ":6,11 ;" " cD''':a$=" Through the TELEVISION SCREEN." h 9000(# l ***T.V.*** m71G,72H:105i,0:0,-579:-105i,0:0,579:79O,64@:65A,0:0,-41):-65A,0:0,41) r?c=40(64@4:151,c:17,0:c w@b=1511684:b,40(:0,24:b |418,19;"":17,19;"" f2:15,10 ;" ":16,10 ;" ":17,10 ;" " 0:9500% op=200:9900& [:2,2;" EXERCISE 2 ":2:24,150:81Q,0:0 _::" Relate these 4 stages to the standard components of a Home Computer system."  7001Y:f=0 x=14  f=f+2 f$,n$ t1:1:16,4;x;". ";:0  10 ,2;x;". ";f$ d$ d$="help"200 d$=n$435 919,7;"WRONG.TRY AGAIN":.5,-20  60< '19,7;" "  415 819,7;"YOU ARE CORRECT":.5,30  60< '19,7;" " x œ9500%::10 ,0;" EXERCISE 2 COMPLETED (CODE GH8)  ":9500%  ւ7:7::2:10 ,4;"WE WILL NOW STUDY THESE COMPONENTS IN GREATER DETAIL." ,#1;" PRESS SPACE TO CONTINUE" X=1100000CP  V=17:V:10 A$=:A$=" "480 V X :1:7:5: {1:4,9 ;" ":5,9 ;" THE KEYBOARD ":6,9 ;" ":0 10 ,2;"This is the most commonly used device for communicating with the computer.":14,2;"At the keyboard the user types in instructions in the form of commands,or responses to requests for information from the computer."  9500% b 4 g :2 l~1:1:4,10 ;"THE CENTRAL":5,10 ;"PROCESSING ":6,10 ;" UNIT. ":0 qr9 ,2;"The C.P.U. is the heart of the system where all the actual computing takes place." va13 ,2;"It examines the instructions given to the computer and obeys them." {Q17,2;"All other elements in the system are connected to it."  9500% z:1:5,2;"In a home computer it is a single chip known as the MICROPROCESSOR." N9 ,2;"C.P.U.'s use a language called MACHINE CODE." 12 ,2;"This is a 'low level' programming language":2:16,4;"i.e.":1:16,8;"A series of binary codes."  9500% :1:9 ,2;"Most home computer users program in a 'high level' language called";:3:" BASIC" Y:1:" (";:3:"B";:1:"eginners ";:3:"A";:1:"ll-"; O:1:"purpose "::3:" S";:1:"ymbolic ";:3:"I"; :1:"nstruction ";:3:"C";:1:"ode)."  9500% :1:6,2;"This was designed as an easy-to-learn language that allows beginners to obtain results with the minimum effort." u:3:" BASIC ";:1:"commands are in the form of words that we can recognise and quickly understand" ;:2:" e.g. ";:1:"PRINT,LIST,RUN,GOTO etc"  9500% :1:9 ,2;"Because of these different languages a device called the BASIC INTERPRETER is built into nearly all home computers"::" It works in the following way-"  9500% ƀ:1:2,2;"KEYBOARD":1,14;"BASIC":2,12 ;"INTERPRETER":2,25;"C.P.U." }0:4,2;"":5,2;"":6,2;"":7,2;"" }5:4,15;"":5,15;" ":6,15;" ":7,15;"" h1:193,143:568,0:0,-31:-568,0:0,31 !x=1932493.5` #x,143:0,-31:x !z=112p1433.5` "193,z:568,0:z ڑ1:12 ,2;"When we input BASIC commands it translates them into the MACHINE CODE understood by the C.P.U." G2:80P,131:111o,0:5,23;">" }5:4,15;"":5,15;" ":6,15;" ":7,15;"" Q1:21,8;"PRESS ";:1:" P ";:0:" TO CONTINUE." "p"745 12 ,2;"Then the results which the C.P.U. produces in MACHINE CODE are translated back into the BASIC understood by the user." I4:191,123{:-111o,0:6,10 ;"<" }5:4,15;"":5,15;" ":6,15;" ":7,15;""  9500% op=610b  9900& a:2,2;" EXERCISE 3 ":2:24,150:81Q,0:1:::  7002Z:f=0 x=14  f=f+2 f$,n$  -1:16,4;x;". ";:0 !9 ,2;" " % 9 ,2;x;". ";f$ *d$ -d$="help"451 / d$=n$830> 4919,7;"WRONG.TRY AGAIN":.5,-20 5 60< 7-19,7;" " 9 810* >819,7;"YOU ARE CORRECT":.5,30 ? 60< A'19,7;" " Cx H:10 ,0;" EXERCISE 3 COMPLETED (CODE JF0)  ":9500% M 3: R1:1: 4,9 ;" ":5,9 ;" MEMORY CHIPS ":6,9 ;" ":0 Wt9 ,2;"To work as a computer the C.P.U. needs a memory.":12 ,2;"This has 2 purposes" \13 ,1;"":a$=" (i) To store INSTRUCTIONS, ie. The programs that tell the computer what to do and how to go about it":9000(# ]G21,8;"PRESS ";:1:" P ";:0:" TO CONTINUE" ^"p"862^ _14,2;" " `-21,8;" " a13 ,1;" ":a$=" (ii)To store INFORMATION i.e.numbers that will be used in calculations, names and addresses, recipes etc.":9000(# f 9500% k:1:9 ,2;"The MEMORY CHIPS inside the computer handle 2 types of memory:"::2:" ROM";:1:" and ";:2:"RAM" p 9500% un:1:2:3,12 ;" ":4,12 ;" ROM ":5,12 ;" ":0 zk7,7;"R";:1:"ead ";:2:"O";:1:"nly ";:2:"M";:1:"emory" :2:" ROM";:1:" is exactly what its name suggests.You can only read the contents of";:2:" ROM";:1:" you cannot add new contents to it." :" It is a ";:2;"PERMANENT";:1;" memory. Its contents are fixed, usually during the manufacturing stage."  9500%  :''''''' 2;" ROM "; 1;"is used to store permanent programs that the CPU will need to use time and time again. For example the BASIC INTERPRETER is a program stored in ";2;"ROM."  9500% }:2:1:3,11 ;" ":4,11 ;" RAM ":5,11 ;" ":0:1 d:2;" R";1;"andom ";2;"A";1;"ccess ";2;"M";1;"emory" l2:10 ,0;" RAM";:1;" can be better described as READ AND WRITE MEMORY." 1:13 ,0;" You can read the contents of";:2;" RAM ";:1;"and you can also add new contents to it." 9500%::1:: 2:9 ,0;" RAM ";:1;"is where the computer keeps the programs it is currently using and where any information required for,or produced,by the program is stored until the computer needs it." 9500%::1 7,0;" It is a TEMPORARY memory."::" As soon as you turn off the power supply the contents of ";:2;" RAM ";:1;"are completely lost." ::" Memory is measured in KILOBYTES (K)." &9500%:op=845M:9700%  7010b [:2,2;" EXERCISE 4 ":2:24,150:81Q,0:1 x=17 f$,n$ -1:16,4;x;". ";:0 9 ,2;" "  9 ,2;x;". ";f$ d$ d$="help"845M d$=n$960 919,7;"WRONG.TRY AGAIN":.5,-20  60< (19,7;" "  952 819,7;"YOU ARE CORRECT":.5,30  60< '19,7;" " x Đ:10 ,0;" EXERCISE 4 COMPLETED (CODE LW9)  ":9500% p:1:4,2;"So far we have only considered the computer's internal memory." ό:" However since the contents of ";:2:"ROM ";:1:"cannot be added to, and the contents of ";:2:"RAM "; |1:"are lost when the power supply is disconnected, we need another form of memory or storage." :2:" i.e.";:1:"A way of storing programs we may want to use again at a later date.":9500% ޙ 4:1::1:4,7;" ":5,7;" EXTERNAL MEMORY ":6,7;" ":0 j9 ,2;"The two methods of EXTERNAL STORAGE that you will encounter are" S: :3;" CASSETTE ";:1;" and ";:3;" DISK":9500% }:3:1:4,11 ;" ":5,11 ;" CASSETTE ":6,11 ;" ":0 1:9 ,2;"Cassette is by far the cheaper of the two systems."::" Using almost any standard cassette recorder you can store programs on tape."  9500% :1:7,0;" For instance if you are building up a basic system you can buy a cassette recorder fairly cheaply, or even use one that you already own." :" However, make sure that the cassette recorder you decide to use has a microphone input and an earpiece output."  9500% :1:7,2;"Another factor for consideration is that if your cassette recorder is old,and the tape head is worn or dirty,this is likely to produce loading errors." }" The volume setting is also crucial.If it is too high, or too low,loading errors will occur."  9500% :1:7,0;" When you SAVE a program on tape,special circuits convert the signals that the computer understands into audio tones.These can be recorded onto tape in the same way as music."  9500% :1:7,0;" When you LOAD the program back into the computer the operation is reversed.The audio tones are converted back into the signals that the computer understands." Q:" The cassette system only allows SERIAL ACCESS to data." $ 9500% ):1:7,0;" For example-You have built up a file on cassette and want to read the 60th item.Therefore you must wait while the tape plays past the first 59 items which precede it." . 9500% 3z:3:1:4,12 ;" ":5,12 ;" DISK ":6,12 ;" ":0:1 88,2;"Disks overcome the problems associated with tape-based storage systems.":'" They are available on an increasing number of home computers." =:" The disk is made of plastic material,coated with a magnetic oxide,then sealed in a protective sleeve." B 9500% Gu:1:9 ,0;" The disk drive contains a motor which spins the disk at about 300 r.p.m." L:" An arm carrying a read/write head is moved,under computer control,back and forth across the disk's surface." Q 9500% V:1:6,0;" To allow the computer to find information easily,the disk's surface is divided up into concentric tracks. These are further divided into a number of sectors." [:" The computer keeps a record of everything saved on the disk in tracks reserved for the DIRECTORY of contents." ` 9500% e :1:7,0;" When you want to use a program you type in its name,the computer looks into the DIRECTORY,and is able to find exactly where it is stored.Then it reads the program and executes it." j 9500% o:1:5,0;" Disks SAVE and LOAD much faster than tape.A program taking 30 minutes to load from tape would be loaded almost instantly from disk." tf:" The computer is also able to INTERROGATE a disk to find unused sections instantly." vo:" In all areas,programs are saved and loaded more reliably using a disk system." y 9500% ~op=970:9900& [:2,2;" EXERCISE 5 ":2:24,150:81Q,0:1 7015g:f=0 x=19  f=f+2 f$,n$ 61:1:16,4;x;". ";:0 9 ,2;x;". ";f$ d$ d$="help"970 d$=n$1210 919,7;"WRONG.TRY AGAIN":.5,-20  60< &19,7;" "  1190 819,7;"YOU ARE CORRECT":.5,30  60< &19,7;" " x Đ:10 ,0;" EXERCISE 5 COMPLETED (CODE KR2)  ":9500% 0:0: 77:1:2,7;"ACL-2 COMPLETED." ::: a$=" 1. YOU HAVE COMPLETED THIS TAPE. "  9000(# a$=" 2. PLACE THE NEXT TAPE INTO THE CASSETTE RECORDER AND ENSURE THAT IT IS FULLY REWOUND." 9000(#:'' a$=" 3. FOLLOW THE LOADING PROCEDURE IN THE MANUAL TO LOAD PROGRAM 3. "  9000(#  0  1230 X("input","processing","memory","output" Y "Input through the--------.","keyboard","Processing through a chip in the computer called the ------- ---------- ----.","central processing unit","Memory through the ------ -----. ","memory chips","Output through the ---------- ------. ","television screen" Z"The heart of the system, where all the actual computing takes place,is called the ------- ---------- ----.","central processing unit","C.P.U's use a language called ------- ----.","machine code","Most home computer users program in a language called -----.","basic","A device called the ----- ----------- acts as a translator between the 2 languages.","basic interpreter" b"The memory chips inside the computer handle --- types of memory.","two","The permanent memory is called ---.","rom","This stands for ---- ---- ------.","read only memory","The TEMPORARY memory is called ---.","ram","This stands for ------ ------ ------.","random access memory","But this is better described as ---- --- ----- ------." cR"read and write memory","Memory is measured in ---------.","kilobytes" g"The first method of external storage discussed was via --------.","cassette","A faster and more reliable method of external storage is via ----. ","disk" h"If a tape head is worn or dirty this is likely to produce ------- ------.","loading errors","If the ------ is too high or too low,loading errors will occur. ","volume" i"----- overcome the problems associated with tape-based storage systems. ","disks","The contents of the disk are recorded in the ---------. ","directory" j "The computer is able to ----------- a disk to find unused sections automatically.","interrogate","----- load and save programs much faster than tape. ","disks" kr"In all areas programs are saved and loaded much more reliably using a ---- system.","disk" @ #( +letters+ #2z=1̱(a$) #< a$(zz); #Fz #P %++SUB+SPACE++ %&50:#1;" PRESS SPACE TO CONTINUE" %+a$= %:a$" "9515+% %<a$= %?a$""9532<% %D &++repeat+sub++ &:4,2;"If you wish to repeat this section before answering the questions which follow, press the key indicated for REPEAT, otherwise press SPACE to continue." &Y13 ,4;"PRESS ";:3:1:" x ";:0:0:" TO REPEAT" &15,14;"OR" &e0:17,4;"PRESS ";:3:1::"SPACE";:0:0:" TO CONTINUE" &a$= &a$=" "9920& & a$="x"op & 9905& & 2#MD@rwfF*Memory is measured in ---------.N kilobytesD kilobytesA