SECTION A FILE INTRO.A ********************************************************* INTRODUCTION TO BASTUTOR - MALLARD BASIC TUTORIAL ON DISC For the PCW8256 and PCW8512 copyright 1990 R A King ********************************************************* WELCOME to BASTUTOR Having flogged through piles of books and spent a small fortune on PCW magazines ,then having spent hours grinding my fingertips down to the knuckles typing in listings, I thought to myself "There must be an easier way to learn MALLARD BASIC!" This course,I hope you will agree, is it. I hope that you will enjoy using it as much as I have enjoyed putting it together. Where BASIC is referred to in the course, MALLARD BASIC is implied. BASIC is not difficult to learn, particularly at primary level, but I found that two things bugged me. Firstly, most authors of computer literature cannot seem to escape from computer jargon, which can be difficult for the newcomer to computers to understand. Computer science has, in common with all other subjects, it's own dictionary of terms which are necessary to describe things unique to computing, and although you will need to learn these sooner or later I have tried, in this course, to explain things in simple everyday English. Since the mass use of computers took off in the USA some computer words are spelled in the American way and this has become the convention and I accept this. 'Program' is a prime example. Secondly there is usually quite a lot of typing to do, copying in examples, before each point can be studied and examined. But in this course most of the work has been done for you, so that you can start right in to find out what makes BASIC tick by experimenting with the programs that are already typed and known to work o.k You should make a copy of your course disc at the earliest opportunity and work with the copy, storing the original master in a safe place. This is always a wise move with any master software as discs can become corrupted or damaged in use. Use DISCKIT to do this as described in your PCW manual, CP/M section. One point which is not explained clearly in the manual is that it may be necessary to put the same side of a disc into the drive two or more times to copy the side completely. This is certainly the case with a standard PCW 8256 without the memory enhancement. A guide is to look at the numbers which appear at the top left-hand corner of the screen during copying, which show the tracks being copied. The final track is 39. Then 'write protect' your copy disc by opening the two small holes at the corners of the case. These holes may be opened or closed by operating shutters behind the holes. The method varies slightly for different makes of disc. The course on this disc is in three sections; INTRODUCTION, PRIMER and INTERMEDIATE . Each section can be selected and accessed from the central BASIC program "TUTOR" as required and is itself a BASIC program. Section programs cannot stand alone without TUTOR. INTRODUCTION This section !! It's main function is to tell you ============ about the course and how to use it, but it also describes BASIC in a general way and introduces you to short BASIC programs. Text files in this section are numbered INTRO.A, INTRO.B etc.,and the holding program is INTRO.BAS PRIMER Here is the start of programming in BASIC. Several ====== fundamental subjects are covered; not in great depth but sufficiently well to enable you to write simple programs. In effect this section introduces most of the more commonly used keywords. Text files in this section are numbered PRIMER.A, PRIMER.B etc., and the holding program is PRIMER.BAS. INTERMEDIATE More advanced work to achieve a reasonable knowledge ============ of understanding and writing BASIC programs. Text files in this section are numbered INTER.A, INTER.B etc. and the holding program is INTER.BAS ******************************************************************* The course is written in MALLARD BASIC saved in ASCII format with text written in LOCOSCRIPT and converted to 'page image' ASCII files. This has been done to allow access to all files from CP/M , simplifying the printing of files and in general making things easier. If you do not understand this now, you will appreciate it later. In PRIMER and INTER sections a piece of text is usually followed by a listing in BASIC, which you can run to see how it performs. You are invited to experiment as much as you like by altering BASIC lines to see what difference is made to the running of the program. Since any modifications made to the program are only in the computer's memory they do not affect the original program on disc, which remains unchanged unless you deliberately save your revised program to the course disc. To guard against this the course disc is supplied "write protected", as described earlier, so that although you can read and use files on the disc you cannot alter anything on the disc or add anything. The course is designed in a rather novel way. In order to keep the course going you have to issue commands (for which prompts are given ). In this way you rapidly learn how to find your way about any BASIC program. I hope that you will take full advantage of the many opportunities to change (EDIT) program lines to see what difference it makes. Don't take my word for anything; try it for yourself. In addition I hope that you will try as soon as possible to write short programs to test what you have learned. You can do this without leaving TUTOR as long as your program lines stay above 50000. All this will be explained in greater detail, including EDITING. The PCW is supplied with a printer and this will be found a great help with the course. Files can be printed out for study away from the computer and also parts of the BASIC program listing can be printed out. It is most useful to do this before EDITING (modifying) a part of the program, so as to compare ' before and after ' When starting a session with the course be sure to have the printer at the ready. Some notes on using the printer are given later. When starting a fresh subject from scratch there is always a lot of groundwork to do. My advice is to read through the files in this section, to try to understand as much as you can, but not to worry if some points seem obscure. You will find that as you work through the course all will become clear and you can always reread a file again later. I hope that as well as initially teaching BASIC this course will be useful for reference. Following this text is a simple program in BASIC to give you an idea of how a BASIC program looks and functions. We apologise in advance for the very weak humour. Enter the y or n where requested and follow the instructions to get the most out of it. If this is your first contact with BASIC don't try to understand the program at this stage .After you have worked through the PRIMER part of the course you will understand most, if not all, of the program. INTRO section J consists of a few short programs which are a little more advanced but which be easily understood once you have worked through the course. For the present, simply regard them as a break from your studies. End of file INTRO.A h the course. For the present, simply regard them as a break from your studies. End of file INTRO