Transparent Ink

Please refer to Syd Wyncoop’s article on Color Codes in the January issue and my article in the December issue (More On Attributes).

I recently read more on this subject that sheds additional light on the use of color attributes. This was found in The Art Of Programming The ZX Spectrum by M James, an English publication. There will be a review on this small book later.

It is possible to assign an attribute to a specific location on the screen and call it up at will. It can be a color as PAPER or INK, and it can be BRIGHT and or FLASH. Try these two lines:

10 PRINT AT 10,10; FLASH 1; "*" 

RUN and there is a flashing . Now add this line and RUN:

20 PRINT AT 10,10; FLASH 8; "BANG" 

The “B° is the only character flashing because it is taking the action given to this location when FLASH 8 is used.

In a program structure it might be used like this:

10 PRINT AT 10,16; FLASH 1;"********"
80 PRINT AT 10,0; FLASH 8; "This line has a flashing word!"

The word “flashing” replaces the 8 “*” by the use of FLASH 8. The same principal applies to to BRIGHT, INK and PAPER and in combination.

For PAPER 8 any new character at the designated location will assume the color of the paper background assigned by PAPER. Such characteristics can be called “transparent” in the sense that it lets the original attribute show thru.

This ability to assign a feature to a specific location would seem to have value in games in conjunction with a color monitor, as well with a B & W monitor.