Those of you who have used light pens on the Electron will have discovered their limitation - low resolution. This is because a light pen can only respond to a character-sized cell.

Sometimes this is overcome by introducing a drag factor whereby a cursor is dragged in the general direction the pen is moving, giving the illusion of pixel resolution.

However this can be clumsy, and only works if the pen is moving - not ideal for drafting.

The Tarantula Touch Tablet from Wigmore House works in a similar way to a light pen, except that the tablet takes the place of the screen and will give you pixel resolution.

It is small enough to fit neatly beside your Electron, but can easily be moved to a more convenient position as it comes with a metre of flex. It connects into the ADVAL port of the Plus 1.

You draw on the tablet with a pen which is connected to it by about half a metre of wire. A button on the end of the pen switches it on and off.

Being triangular rather than round, the pen is easy to hold and the button comfortable to press.

The program accompanying the Tarantula is Mousepaint, the same program used by the Wigmore trackball with a few extensions. (We reviewed the trackball in the October 1985 issue of Electron User.)

Mousepaint runs in Mode 1. Down the right hand side of the screen is a menu of icons and letters showing the options available.

To select from the menu you touch the corresponding area on the table with your pen and press the button.

Some of the many options available are listed in the adjoining panel.

Let's follow one of these options through in practice. To draw a rectangle you first move to the rectangle icon and press the switch.

Then move over to one corner of the rectangle and press the switch again.

Now as you move the pen, you see a rectangle being dragged about. When you are satisfied with its size and position you press the switch again and the rectangle is fixed in place.

The horizontal/vertical line draw is a nice idea which I used a lot. You plot two points roughly where you want a line to be and the program will put the line exactly in place. This is very useful if your hands are still shaking from the eight before or you accidentally jerk the pen at the last moment.

The program is so easy to use that the only time you need to touch the keyboard is when you are entering text.

On selection of the text icon a prompt appears in a small window at the bottom of the screen. You then type in your text, press Return, move the pen to where you want the text to do, and press the button.

All in all, this is a nice package which has many applications, from designing your own screens and title pages to quite sophisticated technical drawing.

As the software's in Basic and is unprotected you can adapt the Tarantula so that it grows with your needs.

1. Freehand sketching:
   What you draw is what you get.
2. Line rubber-banding
   After plotting a start point, a line is stretched between it and wherever the pen is positioned until the button is pressed, when the line is fixed in place.
3. Rectangle rubber-banding
   As with line rubber-banding, only producing rectangles.
4. Horizontal/vertical line draw
   A feature to make perfect horizontal or vertical lines out of slightly diagonal ones.
5. Circles
   When you plot the centre and a point on the circumference.
6. Dotted lines
   As with line rubber-banding but dotted.
7. Text
   This enables you to enter text anywhere you want it on screen.
8. Fill
   A partial fill which may need to be used several times to fill large, complicated shapes.