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Message: 7269
Author: jetsetdanny
Date: 06/01/2020
Subject: Multicolour guardians in JSW48
John Elliott's JSWED's manual states (starting at the bottom of page 22) that "In JSW48, there are four guardian types - horizontal, vertical, arrow and rope. In JSW128 there are ten; the four mentioned earlier, two diagonal types, and flashing versions of all except the arrow and the rope."
The "flashing" versions are called "multicolour" in JSWED itself, e.g. in JSW128 games when choosing the guardian type you can choose "Vertical multicolour", "Horizontal multicolour", "NW/SE multicolour" and "NE/SW multicolour" (the latter two being diagonal ones, of course).
Judging by the description in SkoolKid's disassembly, it looks to me like bits 0-2 in the first byte of the 8-bit-long definition of each guardian class define what type of guardian it is (please correct me if I'm wrong on this). In practical terms, it looks to me that vertical multicolour guardians have #07 in the first byte of their definition (again, please correct me if this is not entirely accurate).
I have uploaded two experimental files on the JSW & MM Community. The first one, "MC guardian 128K.tap", features a stationary (unmoving) multicolour vertical guardian in a JSW128 game file.
The second file, "MC guardian 48K.tap", features the same guardian copied to a JSW48 game file.
Even though there are no multicolour guardians in the JSW48 game engine, as per the JSWED manual, this guardian is still multicolour, or, to be precise, bicolour. If flickers in white and magenta only, which makes the way it flickers (glints? glitters? glows? shimmers? - I'm not sure what verb is best here) less elegant than in the case of the same guardian in the JSW128K game file: the flickering is much faster and less colourful in JSW48 than in JSW128; it does not look as good.
In the JSW128 game file the same guardian flickers in five colours: red, magenta, green, cyan and yellow. Its flickering is much nicer to the eye than in the JSW48 game engine (although I suspect that if white and blue were added to the cycle, it would be even better).
The question I have is this:
Would it be possible to tweak the JSW48 game engine easily (like changing a couple of bytes or adding a little bit of some additional code, I'm not talking about any serious rewriting of the engine) to make this stationary bicolour guardian multicolour, i.e. to make it flicker at least in the five colours that it flickers in in the JSW128 game engine?
I only need it to flicker in a nicer way, I don't need it to move.
Any help on this would be appreciated. 
Daniel
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