required. Remind yourself of the normal settings by producing a sequence of

characters using auto-repeat (and ), then type:

*FX12,1

and repeat the sequence. Now see what happens if you try to produce the same

sequence after typing:

*FX11,Ø

In other words, *FX12 enables you to adjust the speed at which characters are

repeated and *FX11 enables you to adjust the delay before auto-repeat

commences. (*FX11,0 actually switches the auto-repeat facility off altogether).

You can restore both the speed and delay to their initial settings by typing:

*Fx12,Ø

A summary of these, and the host of other special effects is given in Appendix 4.

Finally, the MOS also responds directly to control key depressions, such as

+ G and + L mentioned above. These two examples are complete in

themselves but others, such as + S (which can be used to change the

screen colours in modes 0 -- 6 and modes 128 -- 134) need further keystrokes to

achieve their effect. Select, say, mode 3 and press:

+ S followed by Ø 4 Ø Ø Ø

The five additional characters do not appear on the screen but the MOS

interprets them as a request to change the background colour (0) to blue (4).

Similarly:

+ S followed by 7 1 Ø Ø Ø

changes the text colour (7) to red (1).

+ T, or a subsequent change of mode resets the screen to its default

values of white text on a black background-

Using the disc drives

Your computer is equipped with either one or two disc drives, which store

information and programs for later use. The Welcome disc supplied with the

computer already has programs stored on it; you should refer forwards to the

chapter on Filing Systems for information on how to put the Welcome disc into

the disc drive.

A 13