PETSCII art via Kaleidoscope V4.0

Thought I'd document some of my experiences from last weekend of using Kaleidoscope V4.0 to draw some PETSCII art for my first demo.

Download

I grabbed it from here:

ahearttowitness.com/kscope/


Docs

I found the docs tucked away on the disk, which you accessed via a reader app.

Reading the docs on your PC

If you'd just prefer the comfort of reading the docs on your pc, I exported out the "K.SCOPE4.DOCS" and "ANIMATOR.DOCS" files for easier viewing:

• "k.scope4.docs.txt"
• "animator.docs.txt"

Reading the docs on your C64

• Run the program called "K.SCOPE4.READER" on the disk
• Press SPACEBAR on the title screen
• It then offers a "SCREEN OR PRINTER?" option, select "S"
• documentation then scrolls down the screen, you can pause and un-pause this scrolling with the SPACEBAR.
  

 

 


Loading Kaleidoscope resources into your program

While I didn't find any docs on this, it proved fairly easy to do. The disk has a few example resource files you can try.


Loading via BASIC

I tried loading the "TETRIS" example on the disk via the following simple routine.

5 POKE 53280,0:POKE 53281,0
10 OPEN 5,8,5,"TETRIS,S,R"
20 GET #5,T$
30 PRINT T$;
40 IF ST<>64 THEN GOTO 20
50 CLOSE 5
This got me this lovely animated output I had to use WARP mode in VICE for it to load quicker

 




Loading via Assembly

Well, my effort was more like c-code (via cc65) with some inline assembly, but hopefully there's enough here for someone to derive a 'pure' assembly version out of:

#pragma optimize(off)
void load_petscii(void)
{
 char* file = "tetris,s,r";

 // clear the screen
 __asm__ ( "JSR $E544" );

 // 10 OPEN 5,8,5,"TETRIS,S,R"
 fname_len = strlen(file);
 lo = (unsigned char)((int)file & 0xff);
 hi = ((int)file >> 8) & 0xff;

 __asm__ ( "LDA %v", fname_len);           // A = length of the filename string
 __asm__ ( "LDX %v", lo );                 // LDX #<file;
 __asm__ ( "LDY %v", hi );                 // LDY #>file;
 __asm__ ( "JSR $FFBD" );                  // call SETNAM

 // call SETLFS
 __asm__ ( "LDA #$03" );                   // set file-number to 3
 __asm__ ( "LDX #$08" );                   // device-number 8 (disk drive)
 __asm__ ( "LDY #$03" );                   // secondary address
 __asm__ ( "JSR $FFBA" );                  // call SETLFS

 // call OPEN
 __asm__ ( "JSR $FFC0" );

 while (1)
 {
 // call CHKIN
 __asm__ ( "LDX #$03" );                   // file-number 3
 __asm__ ( "JSR $FFC6" );                  // call CHKIN (file 3 now used as input)

   // 20 GET #5,T$
   // call CHRIN
   __asm__ ( "JSR $FFCF" );                  // the next char is stored in the accumulator

   // 30 PRINT T$;
   __asm__ ( "JSR $FFD2" );                  // call CHROUT

   // 40 IF ST<>64 THEN GOTO 20
   __asm__ ( "JSR $FFB7" );                  // call READST
   __asm__ ( "STA %v", st );                 // store the st value for our c-code

   if (st == 64)
     break;

 }

 // 50 CLOSE 5
 __asm__ ( "LDA #$03" );                     // file-number 3
 __asm__ ( "JSR $FFC3" );                    // call CLOSE

 __asm__ ( "JSR $FFCC" );                    // call CLRCHN
}
#pragma optimize(on)