This routine is one of five words saved on the cassette and further words included in the main programs ZX-PRINTER and WORDACE, which are intended for the advanced user. These enable a wide range of printing options to be generated and customised for your own specific purposes.

However, before these are used, some explanation is required of the principles involved. Usually, the most condensed form of creating information (such as graphics characters) is by means of an algorithm which works like a mathematical formula.

However, complicated and virtually random characters (such as the alphabet) are not readily described in this way, and they have to be stored explicitly in a data array or 'look-up-table'. The words provided here encompass both techniques. When the second method is used, you will see an associated dot addressable array, normally called DOTFILE present (eg. THINPRINT, WORDACE etc.).

You will also see that some operations are performed by supporting words which can be used separately if required. For example, the ITALIC Font uses SLOPE, and the sideways printing in WORDACE uses TURNDOTS.

Whilst most of the words are useful in their own right, the real intention is to illustrate the methods adopted and hence to allow the experienced user to write his own programs based on the same routines.

The second of the five word provided is ACE-LOGO (load ace-logo) which is simply another DOTFILE containing the Jupiter ACE logo held as three 256 byte lines. You may find this handy for heading your printouts to distinguish them from ZX listings. To print the logo you could enter instructions as follows:

ACE-LOGO PRINTLINE ACE-LOGO 256 + PRINTLINE ACE-LOGO 512 +

PRINTLINE Alternatively, why not define another word to do it for you:

: LOGO
3 0
DO
I 256 * ACE-LOGO +
PRINTLINE
LOOP
;