SPECTRA Advanced Graphics

[LCD]

Okay, next part of "Timewasting" for a "dead project":
This function converts RGB (0-3 for each channel) to SPECTRA's 64 colour mode colour:

Code:

function RGBto64Col(r as ubyte,g as ubyte,b as ubyte) as ubyte
    return b|(r<<2)|(g<<4)
end function

And this routine will calculate the memory offset for Quad mode (8x4 Attributes)

Code:

function CalcAdrQuadOffset(x as ubyte,y as ubyte)
    dim y1 as uinteger
    y1=(y&48)+((y&14)>>1)+((y&1)<<3)
    return $6000+x+(y1<<5)
end function

In Double byte colour mode it will return the address of ink byte, for paper byte just add 2048.
Currently I'm writing a small demo to test some SPECTRA abilitys.