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2003-03-21 12:20

Testicle
Account closed

Registered: Sep 2002
Posts: 131

FPP and char-data...

well, after some years of being away from ml-coding on c64, i'm now trying to get back into my old routines.

my first questions is about an 3-color-charset-fpp-scroller. the code looks like this:

.loop lda #$12
sta $d011
lda chartab,x
sta $d018
nop
nop
inx
lda #$13
sta $d011
lda chartab,x
sta $d018
nop
nop
inx
... and so on...

ok, my problem is to figure out, in what way the charset has to be converted. i have the charset in a converted "fpp-table" from $4000 to $8000. can someone explain to me, how to convert a "normal charset" into a "fpp-table"?

i hope, you understand what i mean. ;)

2003-03-21 12:41

HCL

Registered: Feb 2003
Posts: 716

No, i understand nothing.

You have the charset converted to an "fpp-table"? from 4000-8000.. So you already have it converted, why convert it again?!?

What is an "fpp-table" anyway!?

Com'on man, relax and have a beer. It's friday! You're the testicle, rite? ;)

2003-03-21 13:27

Testicle
Account closed

Registered: Sep 2002
Posts: 131

hehe...

> So you already have it converted, why convert it again?!?

well, i don't want to convert the converted char again. it's just that i want to get back the understanding for fpp.

for example, if i have a "normal" 3-color-charset-logo and want to make a fpp-effect with this logo, i have to convert this logo into a kind of "fpp-matrix", so i can make this fpp-effect. i can't use the "normal" char-matrix, which i have for the usual logo-display on screen.

with "fpp-table" i mean the convertet charset. the data of the char, which i use for the fpp-scroller, is stored from $4000 to $8000. and by using different values in $d018, i can choose the pixel-lines from the charset i want to display and create the fpp-effects.

if there are certain "technical terms" for the things i mean, please tell me! :)

2003-03-22 15:23

MagerValp

Registered: Dec 2001
Posts: 1055

charset 0 should have only line 0 of the logo, repeated over and over. charset 1 should have line 1, and so on. So by switching charsets you choose which line to display.

2003-03-22 17:03

Testicle
Account closed

Registered: Sep 2002
Posts: 131

ah, i think i got it. that explains, why only the first byte of each "8-byte-matrix" is set and the 7 following bytes are all $00 - they are not used, because each char displays only one line.

thanks!

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