Dead Display list line

[Grevle]

Im using a mixed mode display with a simple modification to the display list in basic.

 

here is the basic example: 

 

1300 GRAPHICS 28:DL=PEEK(560)+256*PEEK(561):POKE DL+3,66

 

And that is mode 12+16  a multicolor character mode  and one  line at the top with basic text mode 0.

 

And i can put characters and text in this mode 0  line at the top, But when i load the rest of the program witch is mostly assembler then i cannot put anything into this mode 0 line.

 

If i try move the  mode 0 line down then it just blanks out anything just a solid one color mode line is shown. So somehow when i load the rest of the program this mode 0 line seems dead and i cannot reach into it to put anything there.. . The program dos not crash. So i wonder how the rest of my program may make this happen ? something with the VBI adress ? 

 

[Grevle]

Maybe the screen priority can do this ?. it seems the mode 0 line is overlapping anyhing even text i try put into it. when the rest of my program is loaded. Just a solid color bar is shown. I do have a custom character set in the rest of my program, not sure if  that can influence the display list ?.

[Grevle]

Here is a image where i do a test and put the mode 0 line down on screen. As shown here the mode 0 line blanks out anything and i can't put text into it.  The numbers on top are just tests, these are shown in mode 12+16 multicolor.

Edited June 25, 2022 by Grevle

[Rybags]

Don't forget the first line will have LMS so you need to leave the following 2 bytes in the DList alone otherwise the screen memory start could change.

 

Altirra debugger can help with this sort of stuff since you can dump the active DList and see what it's doing.

[Grevle]

10 minutes ago, Rybags said:

Don't forget the first line will have LMS so you need to leave the following 2 bytes in the DList alone otherwise the screen memory start could change.

 

Altirra debugger can help with this sort of stuff since you can dump the active DList and see what it's doing.

 

That would be helpful. Im not exactly sure how it's done. I did locate the displaylist code and seems normal with the lms intact. How can i dump it you mean ?

 

 

[Rybags]

.dumpdlist in the console window (after hit F8 for debugger)

[TGB1718]

1. If your using a custom character set, you probably need to point to the internal character set in a VBI,

then a DLI after that line to switch to your custom character set.

 

in VBI

lda #$e0

sta $d409

sta $2f4

....

 

in DLI

 

pha

lda #<your char set location>

sta $d409

sta $2f4

pla

rti

Edited June 25, 2022 by TGB1718

[thorfdbg]

What are the values of the color registers? Note that in a mode-2 line, you can only set the luminance, but not the color of the foreground. If, by pure chance, the luminance values of playfield 1 and playfield 2 are identical, then there is nothing to see in this line. You may want to trigger a DLI after the LMS 2 line to reload the color registers with something more suitable for the mode-4 lines.

 

[Grevle]

54 minutes ago, thorfdbg said:

What are the values of the color registers? Note that in a mode-2 line, you can only set the luminance, but not the color of the foreground. If, by pure chance, the luminance values of playfield 1 and playfield 2 are identical, then there is nothing to see in this line. You may want to trigger a DLI after the LMS 2 line to reload the color registers with something more suitable for the mode-4 lines.

 

Thank you. I'm gonna look into that. I managed to do a variation fix by putting a text mode 1 at the top or i can use a mode 4 line with custom number characters to appear there.. thanks for the help everybody.?

Edited June 25, 2022 by Grevle

[Grevle]

It was the luminance that did it. I did some remapping of the colors and now it works good. thank you.