|Previous Page > Software Index > Utilities Tape - Charset.|
|Full title||Utilities Tape - charset|
|Year of release||1985|
|Producer / Author(s)||Charles Wehner|
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 third word of the five is CHARSET (load charset) which has two Functions. The first is to reset the original ACE characters after you have redefined them (enter: 0 CHARSET), and the second is in the setting up of a new 'look-uptable' For your own character set.
CHARSET expects an address on the stack where it is to make a 1024 byte character set. For example:
CREATE CHARS 1424 ALLOT CHARS CHARSET gives you space for a character set to play with.
You can easily find the first byte address by entering:
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