ZACK Programming Language
Commands
BACKGROUND (x,y) = value		Set a background tile
BACKGROUND COLLISION from[ .. to]	Test for background collision
BORDER ink				Set Border
BYTE var{ ,var}				Define Byte variable(s)
CLEAR SCREEN byte			Clear the screen
CONSOLE					Output on Console
CONST var = value{ ,var = value}	Define constant(s)
COPY LAYOUT x,y,width,height TO x,y	Copy a section of the Layout
COPY SPRITE n TO n			Copy a Sprite
DEC var					Decrement a variable
DEFINE var = value{ ,var = value}	Define constant(s) (Same as CONST)
DEFINE KEY key				Define a key
DEFINE MAIN TASK number			Define a Main Task
DEFINE MARKER TASK number		Define a Marker Task
DEFINE MOVE TASK number			Define a Move Task
DEFINE DRAW TASK number			Define a Draw Task
DRAW x,y[,pen]				Not implemented (Draw a line)
DRAW TASK number			Execute DRAW Task
ELSE					ELSE statement
ELSE IF expr				ELSE IF statement
ENDIF					End of IF statement
FLASH OBJECT				Flash the current Object
FOR var = start TO end[ STEP step]	For loop statement
GOTO line				GOTO statement
GOTO MARKER marker			Go to Layout Marker
HIDDEN SCREEN				Output on Hidden Screen
IF expr[ GOTO line]			IF or IF .. GOTO statement
INC var					Increment a variable
INK pen, ink				Set the given pen to palette colour
INPUT var[:width]			Assign user input to variable
INSERT HIGH position			Insert a High Score in the table
KILL number				Kill given Object
KILL ALL				Kill all Objects
LOCATE x,y				Position text cursor
MAIN TASK number			Execute MAIN Task
MOVE x,y				Move graphics position
MOVE OBJECT dx,dy[ SCROLL]		Move current Object (include scroll)
MOVE OBJECTS				Execute MOVE Tasks for all Objects
MOVE TASK number			Execute given MOVE Task
NEW OBJECT obj,part,x,y,mt[,dt[,v1..]]	Create a new Object (mt = Move Task, dt=Draw Task)
NEXT					Continue FOR loop
OBJECT COLLISION from[ .. to]		Check for collision with another Object
ORIGIN x,y				Change the output Origin
PAUSE delay[ KEY key]			Pause for given time (or until key pressed)
PLAY FX number				Not implemented (Play given Sound Effect)
PLAY TUNE number			Not implemented (Play given Tune)
PLOT x,y[,pen]				Not implemented (Plot a point)
PRINT [@x,y,]expr[:width]		Print value (at position, with given width)
REPEAT					Repeat loop statement
RESET var{ ,var}			Reset variable(s) to zero
RESET INKS				Reset palette to default???
RETURN					Return from a Task
SCORE var{, var}			Define a Score variable
SCREEN TYPE number			Set the screen format
SCROLL					Scroll the layout (if scrolling on)
SCROLL OFF				Turn automatic scrolling off
SCROLL ON				Turn automatic scrolling on
SHOW BACKGROUND				Show the background
SHOW KEY key				Show the label for the given key
SHOW MINI number			Show given Mini-Sprite at current position
SHOW OBJECT obj,part			Show an Object at current position
SHOW OBJECTS				Show all Objects
SHOW SCREEN				Show the hidden screen
SHOW SHOT number			Show Shot-Sprite at current position
SHOW SPRITE number			Draw a Sprite at the current position
STOP FX					Not implemented (Stop Sound Effect)
STOP TUNE				Not implemented (Stop Tune playing)
STRING var{ ,var}			Define a String variable
SWAP SPRITE number,number		Swap two sprites
UNTIL expr				End of REPEAT..UNTIL loop
VISIBLE SCREEN				Output on the Visible Screen
WEND					End of WHILE loop
WHILE expr				WHILE loop statement
WINDOW x,y,width,height			Define a window for output
WORD var{ ,var}				Define a Word variable
Some of these commands may not be fully implemented.
Functions
ABS expr				Absolute value
BACKGROUND (x, y)			Background tile (x and y in bytes)
DIR obj					Direction of another object (0..7)
INKEY key				Test a key
MAX (value1{, valuen})			Maximum of values
MIN (value1{, valuen})			Minimum of values
NOT expr				Logical NOT
RND					Random Word
System variables
marker Byte Current layout marker number scroll_type Byte Current scroll type (automatic?) x_scrl Byte Current horizontal scroll direction y_scrl Byte Current vertical scroll direction mk_task Byte Task for current marker m1 .. m8 Byte Marker variables lay_x Word Layout X position lay_y Word Layout Y position par_x Word Parallax X position par_y Word Parallax Y position object Byte Object number of current object part Byte Part of current object (0 .. 11) mv_task Byte Task to move object dr_task Byte Task to draw object x Word X position of object y Word Y position of object v1 .. v8 Byte Object variables priority Byte Priority of object y_pos Byte Y co-ordinate from LOCATE x_pos Byte X co-ordinate from LOCATE case Byte CAPS LOCK state ctrl_shift Byte Shift and CONTROL state text_mode Byte Text output mode intno Byte Current interrupt in frame (0 .. 5) screen_type Byte Current screen type flash_mask Byte Mask for flashing objects win_y Byte Window Y of top left win_x Byte Window X of top left win_h Byte Height of window win_w Byte Width of window org_y Byte Window Y origin org_x Byte Window X origin current Byte Current object reference parent Byte Current parent object reference main_pty Byte Priority of objects from tasks back_pty Byte Priority of objects from layout new_pty Byte Priority of next object num_obj Byte Number of objects hit Byte Collision object reference escape Byte Disable/Enable the Escape key high 10 Score Array of high scores name 10 String Array of names for high scores high_pos Byte Position from INSERT HIGH command mask 16 Byte Array of byte masks for each ink sequence ? Byte Background sequence array .object Byte Parent object number .part Byte Parent part .mv_task Byte Parent Move Task .dr_task Byte Parent Draw Task .x Word Parent X location .y Word Parent Y location .v1 .. .v8 Byte Parent object variables
Below is an example ZACK program:
      WORD mky,dots,w1,w2
      BYTE pills,stage,m,power
      PAUSE 10
      SCREEN TYPE 1
      MAIN TASK 1
      DEFINE MAIN TASK 1
0     stage = 1
      m = 0
1     KILL ALL
      NEW OBJECT 1,28,48,0,0,-2
      INC m
      GOTO MARKER m
      mky = lay_y-184
      COPY LAYOUT 256,mky,32,14 TO 0,mky
      x = 24
      y = 0
      FOR v1 = 0 TO m2
      NEW OBJECT 4,x+24,-16,y,1,2,0,0,1,0,0,0,lay_x+x,lay_y-16
      x = x+2
      y = y+4
      IF y=12
      y = 0
      ENDIF
      NEXT
      MAIN TASK 2
      MAIN TASK 3
      WHILE dots
      HIDDEN SCREEN
      SHOW BACKGROUND
      SHOW OBJECTS
      SHOW SCREEN
      CONSOLE
      MOVE OBJECTS
      COPY SPRITE 15 TO 35
      COPY SPRITE 34 TO 15
      COPY SPRITE 33 TO 34
      COPY SPRITE 32 TO 33
      COPY SPRITE 35 TO 32
      IF INKEY 38
      MAIN TASK 2
      ENDIF
      WEND
      INC stage
      IF m1 GOTO 1
      GOTO 0
      DEFINE MAIN TASK 2
      HIDDEN SCREEN
      CLEAR SCREEN 0
      PRINT @11,0,"PAC ATTACK"
      PRINT @12,2,"Stage"
      PRINT @18,2,stage:2
      v2 = 32
      RESET dots,pills
      FOR w2 = mky TO mky+448 STEP 32
      FOR w1 = 32 TO 280 STEP 8
      v1 = BACKGROUND (w1,w2)
      MOVE w1/8+12,v2
      IF v1=0
      v3 = 1
      ELSE IF v1<15
      v3 = 2
      ELSE IF v1<18
      v3 = v1-12
      ELSE
      v3 = 0
      ENDIF
      SHOW SHOT v3
      IF v1=16
      INC dots
      ELSE IF v1=17
      INC pills
      ENDIF
      NEXT
      v2 = v2+4
      NEXT
      PRINT @10,13,"Dots  :"
      PRINT @17,13,dots:4
      PRINT @10,15,"Pills :"
      PRINT @17,15,pills:4
      SHOW SCREEN
      REPEAT
      UNTIL INKEY 47
      DEFINE MAIN TASK 3
      BYTE c1,c2,i1[5],i2[5]
      DEFINE i1[1]=3,i1[2]=2,i1[4]=6,i1[5]=13
      DEFINE i2[1]=3,i2[2]=2,i2[3]=4,i2[4]=0,i2[5]=13
      CONSOLE
      v2 = 1
      FOR w2 = mky TO mky+448 STEP 32
      v4 = 1
      FOR w1 = 32 TO 280 STEP 8
      v1 = BACKGROUND (w1,w2)
      IF v1=0
      v3 = 1
      ELSE IF v1<15
      v3 = 2
      ELSE IF v1<18
      v3 = v1-12
      ELSE
      v3 = 0
      ENDIF
      c1 = i1[v3]
      c2 = i2[v3]
      PLOT v4,v2,mask[c1]
      PLOT v4,v2+1,mask[c2]
      i1[4] = i1[4] XOR 3
      INC v4
      NEXT
      v2 = v2+2
      NEXT
      DEFINE MOVE TASK 0
      power = 0
      w1 = lay_x+28
      w2 = lay_y+48
      IF NOT ((w1 AND 7) OR (w2 AND 31))
      v6 = BACKGROUND (w1+v1*4,w2+v2*4)
      IF v6<16
      v1 = 0
      v2 = 0
      ENDIF
      ENDIF
      IF (lay_y AND 31)=16
      IF v1<2 AND INKEY 63
      v6 = BACKGROUND (w1+8,w2)
      IF v6>15
      v1 = 2
      v2 = 0
      object = 0
      GOTO 1
      ENDIF
      ELSE IF v1>-2 AND INKEY 71
      v6 = BACKGROUND (w1-1,w2)
      IF v6>15
      v1 = -2
      v2 = 0
      object = 1
      GOTO 1
      ENDIF
      ENDIF
      ENDIF
      IF (lay_x AND 7)=4
      IF v2<8 AND INKEY 22
      v6 = BACKGROUND (w1,w2+32)
      IF v6>15
      v1 = 0
      v2 = 8
      object = 3
      ENDIF
      ELSE IF v2>-8 AND INKEY 19
      v6 = BACKGROUND (w1,w2-32)
      IF v6>15
      v1 = 0
      v2 = -8
      object = 2
      ENDIF
      ENDIF
      ENDIF
1     lay_x = (lay_x+v1) AND 255
      lay_y = lay_y+v2
      IF NOT ((w1 AND 7) OR (w2 AND 31))
      v6 = BACKGROUND (w1,w2)
      IF v6=16 OR v6=17
      IF v6=16
      DEC dots
      ELSE
      power = 1
      ENDIF
      BACKGROUND (w1,w2) = 63
      v4 = w1/8-3
      v5 = ((w2-mky+32) AND &FFE0)/16+1
      PLOT v4,v5,0
      PLOT v4,v5+1,0
      ENDIF
      ENDIF
      IF v1 OR v2
      part = (part+1) MOD 6
      ENDIF
      OBJECT COLLISION 4
      IF hit
      BORDER 26
      ENDIF
      DEFINE MOVE TASK 1
      BYTE a,b,d[4],adx[3],ady[3]
      DEFINE adx[1]=8,adx[3]=-8
      DEFINE ady[0]=-32,ady[2]=32
      IF power
      v3 = 255
      IF object=4
      object = 5
      v1 = -v1
      v2 = -v2
      ENDIF
      ENDIF
      IF v3
      DEC v3
      ELSE
      object = 4
      ENDIF
      IF NOT ((w1 AND 7) OR (w2 AND 31))
      v6 = BACKGROUND (w1+v1*4,w2+v2*4)
      IF v1<>0
      a = BACKGROUND (w1,w2-32)
      b = BACKGROUND (w1,w2+32)
      ELSE
      a = BACKGROUND (w1-8,w2)
      b = BACKGROUND (w1+8,w2)
      ENDIF
      IF v6<16 OR (a>15) OR (b>15)
      a = DIR (1)/2
      IF v3
      a = a XOR 2
      ENDIF
      IF a=(v4 XOR 2)
      d[3] = a
      b = 0
      ELSE
      d[0] = a
      b = 1
      ENDIF
      a = RND AND 3
      IF a=(v4 XOR 2)
      a = (a+1) AND 3
      ENDIF
      FOR v4 = b TO b+2
      d[v4] = a
      a = (a+1) AND 3
      NEXT
      d[4] = a
      a = 0
      GOTO 2
1     INC a
      IF a>4
      PAUSE 100
      ENDIF
2     v4 = d[a]
      v6 = BACKGROUND (w1+adx[v4],w2+ady[v4])
      IF v6<15 OR (v6=15 AND ((v4<>0) OR (RND AND 7))) GOTO 1
      v1 = adx[v4]/4
      v2 = ady[v4]/4
      ENDIF
      ENDIF
      w1 = w1+v1
      w2 = w2+v2
      x = MAX (MIN (w1-lay_x,72),-16)
      y = MAX (MIN (w2-lay_y,160),-64)
      part = (part AND 12)+((part+1) AND 3)
Executioner 09:48, 5 September 2006 (CEST)