Sinclair ZX Spectrum Introduction Manual

and Robin Bradbeer PDF Edition 2004 prepared by Colin Woodcock, ZXF Magazine (www.zxf.cjb.net) © 1982 Amstrad Amstrad has kindly given its permission for the redistribution of its copyrighted material, but retains that copyright. ...

CHAPTER 2 The keyboard. Page 8 CHAPTER 3 Numbers, letters and the computer as a calculator. Page 11 CHAPTER 4 Some simple commands. Page 14 CHAPTER 5 Simple programming. Page 17 CHAPTER 6 Using the cassette recorder. Page 21 CHAPTER 7 Colours. Page 25 CHAPTER 8 Sound. Page 27 CHAPTER 9 Inside the case. Page 29 ...

This short booklet has been written for two types of people. First, those who know nothing, or next to nothing, about computers, and, secondly, for those who are familiar with computer based systems but who like to read instruction booklets before plugging anything in. There is a second, thicker book which is the BASIC programming manual. This should not be read by the novice computer user until this booklet has been read and understood. Unpacking the ZX Spectrum, you will have found: 1 This introductory booklet and the BASIC programming manual, 2 The computer. This has three jack sockets (marked 9V DC IN, EAR and MIC ...

Figure 1 If your television has two aerial sockets marked UHF and VHF, then use the UHF one (UK). Turn the power on and switch on the television. You now need to tune the television in The ZX Spectrum operates on channel 35 UHF (UK) and when it is first plugged in and properly tuned it gives a picture like this: Chapter 1 When using the computer, you will probably want to turn the volume on the television right down. If your television has a continuously variable tuning control, then you just have to Figure 2 6 ...

individual push button for each Station. Choose an unused one and tune it in. For use in countries that have a different TV system to that in the UK a version of the ZX Spectrum specially designed for that system is necessary. The UK uses a UHF system with 625 lines and 50 frames per second. It also uses a colour encoding system called PAL. Most countries in Western Europe (except France) use a similar system, and the computer should operate in these countries without any modification. The USA, Canada, and Japan, for example, use a totally different TV system and a diff ...

Type in the letters "Hello". If there is already some other text, for example, on the screen turn the computer of (remove the 9V plug) and start again. Use the CAPS SHIFT key to get the upper case H. In general, anything coloured white above the key requires CAPS SHIFT to access, and anything coloured red on the key requires SYMBOLS SHIFT A command beginning with PRINT tells the computer to write the letters enclosed 2. The Keyboard The keyboard of the Spectrum is very similar to a standard typewriter. The letter and number keys are in the same place; however each key can perf ...

by the computer, the ENTER key must be used. When this has been done the screen should display the word Hello and some other characters. (A flashing question mark indicates a mistake somewhere. If this happens start again and repeat the exercise). The message at the bottom is really the computer reporting back that everything has gone 'OK'. The message is important when running programs but can be ignored at the moment. Notice something else: The letter O and the numeral 0 are represented by different characters. It is important to remember this, The numeral 0 al ...

Pressing the 9 key will change back to L mode. There Is one last mode that the keyboard can be changed to. The extended mode, indicated by an E cursor, is obtained by pressing CAPS SHIFT and SYMBOL SHIFT at the same time. This allows most of the scientific and programming functions to be used. Pressing the two SHIFT keys again will revert the keyboard back to letter, L, mode. Even if you are the most proficient typist or programmer wrong keys get pressed. So far the only way to overcome this has been to pull the plug out. Although this may be convenient if onl ...

as a calculator We have already seen how to tell the computer to print letters and graphics on the screen using PRINT. We have also seen that ENTER has to be used to tell the computer to execute the command just typed in. From now on we will not use ENTER in the manual each time a command is used, but assume that you will key it at the end of the line automatically. Numbers can be handled by the computer more easily than letters. In the previous chapter we hinted at this by explaining that the computer expects a number after PRINT if quotations marks are not used. So if we key PRINT 2 the number 2 will appear on t ...

PRINT “2+2=";2+2 Try some other kinds of arithmetic as well: PRINT 3-2 PRINT 4/5 PRINT 12*2 The * Is used as a multiplication sign instead of X to avoid getting it confused with the letter x; and / is used for the division sign. Experiment with lots of different calculations. If you like you can use negative numbers or numbers with decimal points in. If you do enough to use up the 22 lines of the top par of the screen, then you will notice something rather interesting happening; it will all move up one line and the top line will be lost. This is called scrolling. Calculations are no ...

priority than another, the computer does this by having a number between 1 and 16 to represent the priority of each operation: * and / have priority 8, and + and have priority 6. This order of calculation is absolutely rigid, hut you can circumvent it by using brackets, anything in brackets is evaluated first and then treated as a single number, so that PRINT 3*2+2 gives the answer 6+2=8 but PRINT 3*(2+2) gives the answer 3*4=12 It is sometimes useful to give the computer expressions such as this because whenever the computer is expecting a number from you, you can giv ...

The computer memory can be used to store all sorts of things. We have seen, so far, that the PRINT command allows us to show letters, numbers and the results of calculations using both letters and numbers, on the screen. If we want to tell the computer to remember a number, or a string of letters, then we have to allocate some of the memory for that use. Most pocket calculators have a key called 'memory' which is used for remembering numbers for later. Your computer can do much better than that: it can have as many of these imaginary boxes In it as you like and you write a name on each one. As an example, suppose you want to rem ...

a$ (string variable names can only have a single letter, other than the $, in them). Type LET a$="Your age is " If you now key PRINT a$ back comes the string of letters on the screen. If the computer hasn't been turned off since the start of this chapter type PRINT a$;age and see what happens. There are other ways of getting information into the computer's memory without using the LET command. For example the INPUT command, in its simplest form tells the computer that some information is expected from the keyboard. Instead of typing LET etc. everytime, you can key INPUT age Once the ENTER key has been pressed a flashing L cursor will ...

Up to now we have been telling the computer what to do, directly from the keyboard. Although it is possible to combine commands together, only limited applications are feasible using this method. The great thing about computers is that they are programmable. This means that we can give them a series of instructions to make them do things in a sequence. Every computer has its own language which allows us to communicate with it. Some languages are very simple - so that the computer can understand them easily. Unfortunately languages that are simple for the computer to understand are difficult to humans. In some ways the reverse is ...

This indicates the last line entered. If you want to see the program again key ENTER again, (or LIST) You can use RUN to execute the program as many times as you like. When you no longer need this program, you can remove it by using the NEW command. This wipes out the program stored in memory, and gives you a 'clean slate’ ready to put in a new one. Key NEW then LIST and see what happens. Chapter 5 Figure 4 Figure 5 To recap: When you type in a command preceded by a number then this tells the computer that it is not simply a command, but a program line. The computer does ...