@program        prog_code,prog_name

;************** Start of Fargo program ***************

;Hardware graylevels - by Tleilax
;Temporary E-Mail : zorg@humanoid.net
;This version enables 2 bitplanes 4 gray levels (poor quality)

prog_name:
                dc.b    "Hardware graylevels",0
MyHandle        dc.w    0
Screen1         dc.l    0
Screen2         dc.l    0
Screen3         dc.l    0
Screen4         dc.l    0
Screen5         dc.l    0
Screen6         dc.l    0
DS1             dc.w    0
DS2             dc.w    0
        EVEN

Wait:
        move.w  #100,d0
       WL:
        dbf     d0,WL
        rts

prog_code:
        move    #$2700,sr

        move.l  #4096*5,-(a7)
        jsr     romlib[create_handle]
        add     #4,a7
        
        tst.w   d0
        beq     PC_End
        
        move.w  d0,MyHandle
        handle_ptr     d0,a0

        move.l  a0,d0
        add.l   #7,d0
        and.b   #$f8,d0
        move.l  d0,Screen1
        move.l  d0,d1
        lsr.l   #3,d1
        move.w  d1,DS1
        add.l   #4096,d0
        move.l  d0,Screen2
        move.l  d0,d1
        lsr.l   #3,d1
        move.w  d1,DS2
        add.l   #4096,d0
        move.l  d0,Screen3
        add.l   #4096,d0
        move.l  d0,Screen4
        add.l   #4096,d0
        move.l  d0,Screen5
        add.l   #4096,d0
        move.l  d0,Screen6


        ;Try to change the following values. Many interresting things may
        ;happen.

        move.w  DS1,$600010
        move.b  #$f0,$600012    ;freq?
        move.b  #$0a,$600003

        ;move.b  #$00,$60001f


        move.l  Screen1,a0
        move.w  #64*256/32-1,d0
       PC_Loop1:
        move.l  #$ffffffff,(a0)+
        dbf     d0,PC_Loop1
        
        move.w  #64*256/32-1,d0
       PC_Loop2:
        clr.l   (a0)+
        dbf     d0,PC_Loop2
        
        move.w  #32*256/32-1,d0
       PC_Loop3:
        move.l  #$ffffffff,(a0)+
        dbf     d0,PC_Loop3
        
        move.w  #32*256/32-1,d0
       PC_Loop4:
        clr.l   (a0)+
        dbf     d0,PC_Loop4
        
        move.w  #32*256/32-1,d0
       PC_Loop5:
        move.l  #$ffffffff,(a0)+
        dbf     d0,PC_Loop5
        
        move.w  #32*256/32-1,d0
       PC_Loop6:
        clr.l   (a0)+
        dbf     d0,PC_Loop6
        
        move.l  Screen1,a0
        add     #2,a0
        move.w  #250,d0
       PC_Loop7:
        clr.l   (a0)
        add     #32,a0
        dbf     d0,PC_Loop7

        move.l  Screen3,a0
        move.w  #128*256/32-1,d0
       PC_Loop8:
        move.l  #$ffff0000,(a0)+
        dbf     d0,PC_Loop8
        
        move.l  Screen4,a0
        move.w  #128*256/32-1,d0
       PC_Loop9:
        move.l  #$ff00ff00,(a0)+
        dbf     d0,PC_Loop9
        
;        move.l  Screen5,a0
;        move.w  #128*256/32-1,d0
;       PC_Loop10:
;        move.l  #$f0f0f0f0,(a0)+
;        dbf     d0,PC_Loop10
;        
;        move.l  Screen6,a0
;        move.w  #128*256/32-1,d0
;       PC_Loop11:
;        move.l  #$cccccccc,(a0)+
;        dbf     d0,PC_Loop11
        



        ;bsr     Do_WaitKey
       WLoop:
        move.w  #0,d3
        bsr     Do_GetKey
        cmp.b   #$ff,d3
        beq     WLoop

        

       PC_Free:
        move.b  #$31,$600012    ;freq?
        
        move.w  MyHandle,-(a7)
        jsr     romlib[destroy_handle]
        add     #2,a7
       PC_End: 
        move.w  #$4440/8,$600010
        move    #$2000,sr
        rts



Do_WaitKey:
	move.l  #$75AA,a0
       DWK_Loop:
	tst.w   6(a0)
	beq     DWK_Loop

	clr.w   6(a0)

	move.w  8(a0),d0

	rts

Do_GetKey:
	move.w  d3,($600018)
	nop
	nop
	nop
	nop
	move.b  ($60001B),d3
	rts



;*************** End of Fargo program ****************

        reloc_open
        add_library     romlib
        reloc_close
	end