The BBC and Master Computer Public Domain Library

DRAW

Professional, Originally Released On Cassette Only

Game Type          : Art Package

Author             :

Standalone Release(s)   : 1984: DRAW, Micro Power, £7.95

Compilation Release(s)   : None

Stated compatibility    : Electron

Actual compatibility    : Electron, BBC B, B+ and Master 128

Supplier            : MICRO POWER, 8/8A Regent Street, Chapel Allerton, LEEDS

                    LS7 4PE. Tel: 01532 683186.

Disc compatibility     : Unknown

Instructions

Instructions currently unavailable.

Review (ELBUG)

Both parts of this package are written in BASIC, and loading is very easy. One fact that became obvious once the programs had loaded was that this was a BBC Micro version in an Electron case. The title page is a Mode 7 display, and includes double-height control codes which the Electron cannot apply to its display!

The package provides a new programming environment for the user. Some Electron owners may already have take the time to investigate the Turtle program provided on the B side of the INTRODUCTORY CASSETTE and described in the book START PROGRAMMING WITH THE ELECTRON by Masoud Yazdani that comes with the Electron. DRAW provides similar facilities, but also has other features. All interaction with the package takes place in Mode 4, with the screen neatly split into two halves vertically. The left hand half is used for prompting, while the right hand half displays useful information.

Drawing consists of a series of commands that are similar to some BASIC commands. For example, the following DRAW 'program' will produce a square on the screen:

      SQUARE SIZE

      repeat 4

      move SIZE

      turn 90

      end repeat

      finish

The first line names a procedure as 'SQUARE', and gives it the parameter SIZE. This allows the routine to be used to produce a square of any given size, for example:

      SQUARE 100

will draw a square of size 100 units.

If you follow through the commands comprising the program, you should see how logical and simple a program in DRAW (and LOGO for that matter), can appear. Using procedures like these as building blocks, you can go on to define very complex routines to draw a variety of geometrically based shapes on the screen.

Programs are stored internally with an identifying name. When you ask to run a program (achieved by pressing 'R'), then all the names of the programs held within memory are listed out, along with an associated number. You now type in this number, press RETURN, and the program is run. As you may have gathered, DRAW allows more than one program to be resident in memory at once. In fact, you can have up to 20 programs in memory together, each with up to thirty lines.

The commands allowed within a program are: move, turn, repeat, end repeat, program, pen up, pen down, finish. In addition to this, you may use any procedures of your own that you have already defined.

In conclusion, the DRAW package seems well thought out and provides clear menus to help the inexperienced user. The manual is a photocopied one, and lacks the legibility in places that one would expect of Micro Power, but the description of the program is more than adequate.

The program is apparently designed to run on both the Electron and the BBC Micro. When available, the program will be able to take advantage of a printer, if attached, to produce a hard dump copy of the screen. The program could, however, have been better prepared for the Electron (Micro Power have said that a new version will be produced), and I would think that most users will find the Turtle program on the INTRODUCTORY CASSETTE to be quite adequate. Rating: ***

David A. Fell, ELBUG 1. 4

Review (Electron User)

The blurb inside the cassette box tells you that DRAW is "an implementation of a sub-section of the LOGO language, principally its turtle graphics". Off-putting, isn't it?

I had two or three programs to review and left this one until last as it sounded as dreadfully dull. This was a mistake, as I soon discovered. I loaded the program and turned to the tutorial section of the excellent little manual that comes with the cassette. This led me through all of the programming techniques available with Draw. Written simply and clearly, it was a pleasure to use, unlike some of the other manuals I've come across.

By the time I'd read and worked through it on my Electron, Draw wasn't off-putting, it was fascinating. At one level, the program allows you to produce pretty patterns on the screen, quickly and easily. At another level, it introduces the beginner to the basics of programming using a simple graphics-orientated language. The fact that it is so much fun to use encourages experiment and learning.

The whole thing is menu-driven, which means that your Electron gives you a series of choices and you can take your pick. This allows you to get any of the commands by one or two keystrokes, making the program very pleasant to use.

It's educational, it's fun and it's easy to use, being one of the nicest programs I've come across in a long while. If you're looking for something that's both out of the usual and entertaining then Draw might just be it.

Trevor Roberts, ELECTRON USER 1. 5