Merge pull request #76 from zbyti/master

ANTIC Display List Instruction Set constans & some refactor

examples/README.md

@@ -110,6 +110,8 @@ how to create a program made of multiple files loaded on demand
 
 ### Other examples
 
+* [Test OS module](a8/a8_os_test.mfk) – quick test for a8_os.mfk module
+
 * [Rainbow example](a8/rainbow.mfk) – simple scrolling rasterbars
 
 * [Quatari Landscape](a8/landscape.mfk) – part of Quatari 256B intro

examples/a8/dli_example.mfk

@@ -2,9 +2,12 @@ const word dlAddr = $3000
 const word dliAddr = $3100
 
 const array(byte) dl @ dlAddr = [
-  $70,$70,$70,
+  BLANK_8,BLANK_8,BLANK_8,
-  $42,$00,$40,2,2,2,2,$f0,2,2,2,2,
+  LMS|MODE_2,$00,$40,
-  $41,@word[dlAddr]
+  MODE_2,MODE_2,MODE_2,MODE_2,
+  BLANK_8|DLI,
+  MODE_2,MODE_2,MODE_2,MODE_2,
+  JVB,@word[dlAddr]
 ]
 
 volatile word SDLST @ $230

examples/a8/landscape.mfk

@@ -1,5 +1,6 @@
 // idea @ilmenit
-// https://demozoo.org/productions/280623/
+// https://demozoo.org/productions/280623
+// for 8bit AtariXL, OS Rev 2
 
 alias prev_x = os_OLDCOL.lo
 alias cursor_x = os_COLCRS.lo
@@ -23,20 +24,17 @@ void main(){
   for i,0,to,79 {
     cursor_x = i
     prev_x = i
-    color = 13
     prev_y = 1
 
-    while color != $ff {
+    for color,13,downto,0 {
       cursor_y = color_height[color]
-      if (pokey_random & 1) != 0 {
+      if pokey_random < $80 {
+        color_height[color] -= 1
+      }
+      if pokey_random <  $80 {
         color_height[color] += 1
-      } else {
-        if (pokey_random & 1) != 0 {
-          color_height[color] -= 1
-        }
       }
       drawto()
-      color -= 1
     }
   }
 

include/a8_antic.mfk

@@ -4,6 +4,44 @@
 #warn a8_antic module should be used only on Atari computer-compatible targets
 #endif
 
+// ANTIC Display List Instruction Set
+// THE DISPLAY LIST CANNOT CROSS A 1K BYTE MEMORY BOUNDARY UNLESS A JUMP INSTRUCTION IS USED!
+const byte LMS     = $40          // Load memory scan 10-bit counter, $fff boundary.
+const byte DLI     = $80          // Display list interrupt - Interrupt CPU at beginning of last scan line.
+const byte HSCROL  = $10          // Enable horizontal scrolling.
+const byte VSCROL  = $20          // Enable vertical scrolling.
+const byte JMP     = 1            // Jump command - followed by two bytes indicating the new instruction pointer for the display list.
+const byte JVB     = $41          // Jump and wait for Vertical Blank - suspends the display list until vertical blank and then jumps.
+
+                                  //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+                                  //+  BASIC  + colors + resolution + display mode + scan lines per row + screen memory + bytes per line + bits per pixel +
+const byte MODE_2  = 2            //+    0    +    2   +   40x24    +     text     +        8           +     960 B     +       40       +      8         +
+const byte MODE_3  = 3            //+    -    +    2   +   40x24    +     text     +       10           +     760 B     +       40       +      8         +
+const byte MODE_4  = 4            //+   12    +    5   +   40x24    +     text     +        8           +     960 B     +       40       +      8         +
+const byte MODE_5  = 5            //+   13    +    5   +   40x12    +     text     +       16           +     480 B     +       40       +      8         +
+const byte MODE_6  = 6            //+    1    +    5   +   20x24    +     text     +        8           +     480 B     +       20       +      8         +
+const byte MODE_7  = 7            //+    2    +    5   +   20x12    +     text     +       16           +     240 B     +       20       +      8         +
+const byte MODE_8  = 8            //+    3    +    4   +   40x24    +   graphics   +        8           +     240 B     +       10       +      2         +
+const byte MODE_9  = 9            //+    4    +    2   +   80x48    +   graphics   +        4           +     480 B     +       10       +      1         +
+const byte MODE_A  = $a           //+    5    +    4   +   80x48    +   graphics   +        4           +     960 B     +       20       +      2         +
+const byte MODE_B  = $b           //+    6    +    2   +  160x96    +   graphics   +        2           +    1920 B     +       20       +      1         +
+const byte MODE_C  = $c           //+   14    +    2   +  160x192   +   graphics   +        1           +    3840 B     +       20       +      1         +
+const byte MODE_D  = $d           //+    7    +    4   +  160x96    +   graphics   +        2           +    3840 B     +       40       +      2         +
+const byte MODE_E  = $e           //+   15    +    4   +  160x192   +   graphics   +        1           +    7680 B     +       40       +      2         +
+const byte MODE_F  = $f           //+8,9,10,11+    2   +  320x192   +   graphics   +        1           +    7680 B     +       40       +      1         +
+                                  //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+
+const byte BLANK_1 = 0
+const byte BLANK_2 = $10
+const byte BLANK_3 = $20
+const byte BLANK_4 = $30
+const byte BLANK_5 = $40
+const byte BLANK_6 = $50
+const byte BLANK_7 = $60
+const byte BLANK_8 = $70
+
+//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+
 volatile byte antic_dmactl @$D400 // direct memory access control
 volatile byte antic_chactl @$D401 // character mode control
 volatile word antic_dlist  @$D402 // display list pointer