Mad Pascal and display list interrupts

[Gury]

Display list interrupt example:

 

{
  Display list interrupt example
}
uses crt, graph;

var
  dlist : word;

procedure DLI_routine;
begin
  asm
  {  
  stx @sp
    
  lda #<dli  ; Set up our display list interrupt vector
  sta $200
  lda #>dli
  sta $201
  lda #$c0   ; Enable DLI + Vertical blank routines
  sta nmien
  };
  
  gotoxy(8, 16); writeln('Some more text...');  
  
  asm
  {
loop
  jmp loop    ; Wait forever     
        
dli
  pha         ; Save registers
  lda #0      ; New text color
  ldx #36     ; New background color
  stx WSYNC   ; Wait 
  sta COLPF1  ; Store color
  stx COLPF2  ; Store color
  pla         ; Restore registers
  rti         ; Done

  ldx @sp
  };  
end;
  
begin
  InitGraph(0); CursorOff;
  dlist := DPeek($230);
  Poke(dlist+16, 130);
  gotoxy(6, 5); writeln('Display list interrupt example');
  DLI_routine;
  gotoxy(8, 20); writeln('Is this text shown?');    
  repeat until 1;
end.

dli1.xex

[pps]

hmm - reads as if this one never leaves the DLI_routine:

loop
     jmp loop

so this will never occur:

gotoxy(8, 20); writeln('Is this text shown?');
repeat until 1;

or am I missing something?

 

... I did some small changes and now it works as it should:

 

replace the loop jmp loop with a simple rts

 

and add =0 to have an endless loop behind: repeat until 1

gury_dli.obx -> compiled programme

guri_dli.zip -> .pas file

Edited October 20, 2015 by pps

[Gury]

Yes, I did it intentionally, but I hoped for someone to fix it for me. And here you came with a solution, thanks

 

rts is what I was looking for.

 

Greetings

[pps]

Ah... Move the ldx @sp in front of the rts. This way it will be executed...

[funkheld]

wonderful ....

 

thanks.

greeting

[Gury]

Display list interrupt example 2 - Multicolor graphics 0 screen

{
  Display list interrupt example 2
  Multicolor graphics 0 screen
}
uses crt, graph;

var
  i : Byte;
  dlist : word;

procedure DLI_routine;
begin
  asm {
  stx @sp  

  lda #<dli  ; Set up our display list interrupt vector
  sta $200
  lda #>dli
  sta $201
  lda #$c0   ; Enable DLI + Vertical blank routines
  sta nmien

  ldx @sp
  rts

dli
  pha         ; Save accumulator
  lda VCOUNT  ; Load accumulator with Vertical line counter value
  sta WSYNC   ; Wait for horizontal sync 
  sta COLPF2  ; Color and luminance of playfield 2
  sta COLBAK  ; Color and luminance of the background
  pla         ; Restore accumulator
  rti         ; Done with display list interrupt
  };
end;

begin
  InitGraph(0); CursorOff;
  dlist := DPeek($230);
  // Set colors for 8 lines at the top
  fillchar(pointer(dlist+10), 8, 130);
  // Set colors for bottom lines
  fillchar(pointer(dlist+21), 4, 130);
  // Some text
  gotoxy(5, 3); writeln('Display list interrupt example 2');
  gotoxy(5, 4); writeln('Multicolor graphics 0 screen');
  // Display list interrupt routine
  DLI_routine;
  // More text
  for i := 0 to 7 do begin  
    gotoxy(8, 16+i); writeln('Some more text on line ', 16+i);
  end;
  // Endless loop
  repeat until 1=0;
end.

 

dli2.xex

[funkheld]

hello, wonderful this Mad Pascal.

 

greeting