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From: G60LG@CUNYVM.BITNET (Anton Mitchell)
Newsgroups: comp.sys.amiga.programmer
Subject: Assembly Graphics Help Needed
Message-ID: <91177.015130G60LG@CUNYVM.BITNET>
Date: 26 Jun 91 05:51:30 GMT
Organization: City University of New York/ University Computer Center
Lines: 212


     I have tried to get this assembly program to work for the longest.
Any help would be great. What I dont understand is when assembled and
executed the bitplanes are not cleared. When allocating the memory I set
the Clear and Chip flags. But it is not cleared. The only way I have been
able to clear the bitplanes is by using:
                                         lea     PlaneAdr,a1
                                         move.l  PlaneSize*6,d1
                                 Loop:   move.w  #0,(a1)+
                                         dbra    d1,Loop
Also when executed several times the bars which usually present in a
blue wind up with other colors etc. And after several executions it will
not execute. Any help on what is wrong with the code would be great. I
have just started programming Assembly and I am going crazy with this
program.

                                             Thanks in Advance,
                                             Anton Mitchell





;CustomChip-Register

INTENA  EQU $9A
DMACON  EQU $96
COLOR00 EQU $180
VHPOSR  EQU $6

;COPPER REGISTER

COP1LC  EQU $80
COP2LC  EQU $84
COPJMP1 EQU $88
COPJMP2 EQU $8A

;BITPLANE REGISTER

BPLCON0 EQU $100
BPLCON1 EQU $102
BPLCON2 EQU $104
BPL1PTH EQU $0E0
BPL1PTL EQU $0E2
BPL1MOD EQU $108
BPL2MOD EQU $10A
DIWSTRT EQU $08E
DIWSTOP EQU $090
DDFSTRT EQU $092
DDFSTOP EQU $094

;CIA-A PORT REGISTER A (MOUSE BUTTON)

CIAAPRA EQU $BFE001

;EXEC LIBRARY BASE OFFSETS

OpenLibrary  EQU -552
CloseLibrary EQU -414
Forbid       EQU -132
Permit       EQU -138
AllocMem     EQU -198
FreeMem      EQU -210

;Grafix Base

StartList   EQU 38

;Other Labels

ExecBase   EQU 4
PlaneSize  EQU 40*200
CLsize     EQU 13*4
Chip       EQU $02
Clear      EQU $10000+Chip

;****** Initialize Main Program ********
;Request memory for bitplanes

Start:
 move.l ExecBase,a6
 move.w #PlaneSize*6,d0
 move.w Clear,d1

 jsr    AllocMem(a6)
 move.l d0,Planeadr
 beq    Exit

 move.l Planeadr,a1
 move.l #PlaneSize,d1
LoopA:
 move.w #%11110000,(a1)+
 dbra   d1,LoopA

;Request Memory for copperlist

 moveq  #CLsize,d0
 moveq  #Chip,d1
 jsr    AllocMem(a6)
 move.l d0,CLadr
 beq    FreePlane

; Build CopperList
 moveq  #5,d4
 move.l d0,a0
 move.l Planeadr,d1
 move.w #BPL1PTH,d3

MakeCL:
 move.w d3,(a0)+
 addq.w #2,d3
 swap   d1
 move.w d1,(a0)+
 move.w d3,(a0)+
 addq.w #2,d3
 swap   d1
 move.w d1,(a0)+
 add.l  #PlaneSize,d1
 dbf    d4,MakeCL
 move.l #$fffffffe,(a0)


;*******Main Program *********
; DMA Task switching off

 jsr    Forbid(a6)
 lea    $dff000,a5
 move.w #$03e0,DMACON(a5)

;Copper Initialization

 move.l CLadr,COP1LC(a5)
 clr.w  COPJMP1(a5)

;Color Table with different color fills

 moveq  #31,d0
 lea    COLOR00(a5),a1
 moveq  #1,d1

SetTab:
 move.w d1,(a1)+
 mulu   #3,d1
 dbf    d0,SetTab

;PlayField Initilization
 move.w #$2C81,DIWSTRT(a5)
 move.w #$F4C1,DIWSTOP(a5)
 move.w #$0038,DDFSTRT(a5)
 move.w #$00d0,DDFSTOP(a5)
 move.w #%0110001000000000,BPLCON0(a5)
 clr.w  BPLCON1(a5)
 clr.w  BPLCON2(a5)
 clr.w  BPL1MOD(a5)
 clr.w  BPL2MOD(a5)

;DMA on
 move.w #$8380,DMACON(a5)

Wait:
 btst   #6,CIAAPRA
 bne    Wait

;****** END LOOP ******

;Activate Old CopperList

 moveq   #0,d0
 move.l  ExecBase,a6
 lea     GFXName,a1
 jsr     OpenLibrary(a6)
 move.l  d0,GFXBase
 movea.l d0,a4


 move.l StartList(a4),COP1LC(a5)
 clr.w  COPJMP1(a5)
 move.w #$8060,DMACON(a5)
 jsr    Permit(a6)

;Free Memory for Copper List

 move.l CLadr,a1
 moveq  #CLsize,d0
 jsr    FreeMem(a6)

;Free Memory for BitPlanes

FreePlane:
 move.l Planeadr,a1
 move.l #PlaneSize*6,d0
 jsr    FreeMem(a6)


 movea.l 4,a6
 move.l  GFXBase,a1
 jsr     CloseLibrary(a6)

Exit:
 clr.l   d0
 rts

;Variables
CLadr:     dc.l 0
Planeadr   dc.l 0
GFXBase    dc.l 0

;Constants
GFXName dc.b "graphics.library",0

Program end
 end