yllawwally

I've used the 2600, 7800, and 5200 on my lcd Tv's with no problems. The colors were nice, only thing I didn't like was they were too crisp. The atari seems to look better with a little bleed. How are you connecting yours? Do you have an A/V mod?

3 Atari 2600 1 atari 5200 1 atari 7800 1 atari jaguar 1 flashback II

You could get probably albert to make you a cart. It looks like the store is down right now. Try emailing [email protected] If you really wanted to make them yourself you would need an eprom burner, to program the games. Then you would need blank eproms, invertors, and pcbs.

Do you have a multimeter? It still sounds like a power problem to me. Take the meter, and set it to DC, for 10 volts. With the Atari powered on, place the black lead, to the middle leg of the 7805. Then place the red leg to each of the legs. One leg should measure 9-10volts. The other leg, must measure 5v. If you have less than 5v on one leg, and less than 7 on the other it's your power supply. The 2600 uses a lot of current, 500ma. There should be a list of voltages and currents listed on the power supply. You can check there, many of the multi voltage supplies I've seen only have 300ma at 9v.

I have a 4 line scrolling background across the top. However it doesn't display properly, when scrolling. this is the code I use to setup a line LDA PFData0 ; 4 cycles STA PF0_L1 LDA PFData1 ; 4 cycles STA PF1_L1 LDA PFData2 ; 4 cycles STA PF2_L1 LDA PFData3 ; 4 cycles STA PF3_L1 LDA PFData4 ; 4 cycles STA PF4_L1 LDA PFData5 ; 4 cycles STA PF5_L1 LDA PFData6 ; 4 cycles STA PF_TEMP LDA Screen_Location+1 AND #000011 CLC ADC #1 TAY ROTATE1 ROL PF_TEMP ROR PF5_L1 ROL PF4_L1 ROL PF3_L1 ROR PF2_L1 ROL PF1_L1 ROL PF0_L1 DEY BNE ROTATE1 face30.txt

I was thinking a very basic one would check if a line was ended without using a wsync.

Can Stella tell you which section of your code, is going over the 76 machine cycle line limit?

I have my code set for four sets of creatures to go accross the screen. These four enemies don't move up and down. However the hero needs to go up and down. When he crosses the boundry he gets a little messed up. I've been trying to get this working for a couple weeks. How are other people doing this? I looked into VDEL, but I wasn't sure how to implement it. I was able to get the hero to cross the bottom two sections, without messing up the graphics, but the other transistions are giving me problems. face25.txt

I figured why I needed to offset the graphics and start positions of the creatures. I wasn't decrementing their skipdraw counters on each scanline. So the first was off by 20 lines, the next one by the 20 lines plus the 50 the first was displayed within, and this continued with the next 2 as well. I had trouble finding time to decrement all 5 counters on each scanline. How are other people doing this? I'm going to change the value used for the top of the screen for each creature, so that position 172 is the same place for all the creatures, without the need for all the decrementing.

Now I have the creatures moving properly. Thanks for all the help. There are four lines of sprites. Why do I need to position them at the same place, for them to appear. If I set each P?_YPosFromBot to 172, and place an offset for the skip draw code, they show up. If I don't make these modifications, they don't show up. When I move the hero up the shift as well, such that he loses two pixels on the 3rd row, then two more on the 2nd, and 4 on the 1st. ;Setting some variables... LDA #172 STA P0_YPosFromBot LDA #50 STA P0_XPos LDA #122 ;was 172 STA P1_YPosFromBot LDA #50 STA P1_XPos LDA #72 ;was 172 STA P2_YPosFromBot LDA #50 STA P2_XPos LDA #22 ;was 172 STA P3_YPosFromBot LDA #50 STA P3_XPos ;setup pic animations ---------------------------------------------- lda #<MainPlayerGraphics2 ;low byte of ptr is graphic CLC ;clear carry ADC PICS sta P2_Ptr ;(high byte already set) lda #>MainPlayerGraphics2 ;high byte of graphic location sta P2_Ptr+1 ;store in high byte of graphic pointer lda #C_KERNAL_HEIGHT + #C_P0_HEIGHT - #1 sec sbc P2_YPosFromBot ;subtract integer byte of distance from bottom sta P2_Y lda P2_Ptr sec sbc P2_YPosFromBot ;integer part of distance from bottom clc adc #C_P0_HEIGHT+#92 sta P2_Ptr ;2 byte ;setup pic animations ---------------------------------------------- ;setup pic animations ---------------------------------------------- lda #<MainPlayerGraphics3 ;low byte of ptr is graphic CLC ;clear carry ADC PICS sta P3_Ptr ;(high byte already set) lda #>MainPlayerGraphics3 ;high byte of graphic location sta P3_Ptr+1 ;store in high byte of graphic pointer lda #C_KERNAL_HEIGHT + #C_P0_HEIGHT - #1 sec sbc P3_YPosFromBot ;subtract integer byte of distance from bottom sta P3_Y lda P3_Ptr sec sbc P3_YPosFromBot ;integer part of distance from bottom clc adc #C_P0_HEIGHT+#142 sta P3_Ptr ;2 byte ;setup pic animations ---------------------------------------------- face.bin

So if you characters were always going to be in the same position or moving to the left, then you could hit the hmove and not get the black bar penalty? It certainly is a strange way of doing things.

why does an hmove cause a black bar?

I didn't think about that it would only need to be positioned one per frame, I'll make those changes later. I am reusing the player0 for 4 different sprites. The modified code with sta hmove added is shown below. The first copy works properly, why do the 2 clones not use the fine positioning? They act the same as before. ScanLoop ;start of kernal +++++++++++++++++++++++ for player 0 ;skipDraw ; draw player sprite 0: lda #C_P0_HEIGHT-1 ; 2 dcp P0_Y ; 5 (DEC and CMP) bcs .doDraw0 ; 2/3 ; should be bcs lda #0 ; 2 .byte $2c ;-1 (BIT ABS to skip next 2 bytes)(kinda like a jump) .doDraw0: lda (P0_Ptr),y ; 5 sta GRP0 ; 3 = 18 cycles (constant, if drawing or not!) lda P0_XPos ;lda #30 ldx #0 sec ; 2 set carry .Div15 sbc #15 ; 2 bcs .Div15 ; 3(2) tax lda fineAdjustTable,x ; 13 -> Consume 5 cycles by guaranteeing we cross a page boundary sta HMP0 ;,x sta RESP0 ;,x ;the x must be a 0 for player 0 or 1 player 1 DEY ;count down number of scan lines 2 cycles = STA WSYNC ;3 cycles = STA HMOVE CPY #150 BCS ScanLoop ;2 cycles = EndScanLoop ;end of kernal +++++++++++++++++ for player 0

I have 4 sets of creatures. Only the top row is currently set to move. However the movement is jerky. It only moves in 8 pixel jumps. I am trying to to use, what I think is called battlezone positioning? I was hoping someone could point out what I'm doing wrong here. Here is the code to draw the first row, full source is attached. ScanLoop ;start of kernal +++++++++++++++++++++++ for player 0 ;skipDraw ; draw player sprite 0: lda #C_P0_HEIGHT-1 ; 2 dcp P0_Y ; 5 (DEC and CMP) bcs .doDraw0 ; 2/3 ; should be bcs lda #0 ; 2 .byte $2c ;-1 (BIT ABS to skip next 2 bytes)(kinda like a jump) .doDraw0: lda (P0_Ptr),y ; 5 sta GRP0 ; 3 = 18 cycles (constant, if drawing or not!) lda P0_XPos ;lda #30 ldx #0 sec ; 2 set carry .Div15 sbc #15 ; 2 bcs .Div15 ; 3(2) tax lda fineAdjustTable,x ; 13 -> Consume 5 cycles by guaranteeing we cross a page boundary sta HMP0 ;,x sta RESP0 ;,x ;the x must be a 0 for player 0 or 1 player 1 DEY ;count down number of scan lines 2 cycles = STA WSYNC ;3 cycles = CPY #150 BCS ScanLoop ;2 cycles = EndScanLoop ;end of kernal +++++++++++++++++ for player 0 face15.txt

OK I got it fixed. Here's code of it working. face11.txt

Thanks for the help. I can move around the character. However it seems that P0_Y isn't set properly. I'm not sure where I'm going wrong here. The graphics of the character simply shift through the memory , and you can see the proper graphics if you happen to have the character in just the right spot. face10.txt

Why am I getting value in lda (P0_Ptr),y must be <$100, when I compile. face9.txt

OK I'll just insert a file. Apparently paste doesn't like, binary numbers? And the uploader doesn't like .asm files. wallyface8.txt

I don't know what happened to the graphics info. In the original source, it's all in binary. Something about pasting it here, damaged it. processor 6502 include vcs.h org $F000 ;Variables ------ YPosFromBot = $80; VisiblePlayerLine = $81; PICS = $82; ROLLING_COUNTER = $83; Graphics_Buffer = $84 YPosFromBotE1 = $85; VisibleEnemyLine = $86; VisibleEnemyLineCurrent = $87; EnemyLineBuffer = $88; VisiblePlayerLineCurrent = $90; BG_0 = $91; BG_1 = $92; BG_2 = $93; ; Constants ------ playerheight ds #8; ;generic start up stuff... Start SEI CLD LDX #$FF TXS LDA #0 STA ROLLING_COUNTER STA PICS STA EnemyLineBuffer ClearMem STA 0,X DEX BNE ClearMem LDA #$00 ;start with a black background STA COLUBK LDA #$1C ;lets go for bright yellow, the traditional color for happyfaces STA COLUP0 ;Setting some variables... LDA #80 STA YPosFromBot ;Initial Y Position STA YPosFromBotE1 LDA #010001 ; 2 cycles STA BG_0 ; 3 cycles STA BG_1 ; 3 cycles STA BG_2 ; 3 cycles ;; Let's set up the sweeping line. as Missile 1 LDA #2 ; STA ENAM1 ;enable it LDA #33 STA COLUP0 ;color it STA COLUP1 ;color it LDA #$10 ; STA NUSIZ0 ;make it quadwidth (not so thin, that) STA NUSIZ1 ;make it quadwidth (not so thin, that) LDA #000000 ; set to not move STA HMM1 ; of HMM1 sets it to moving ;VSYNC time MainLoop ;+++++++++++++++++++++++++++The start of a new screen LDA #0 STA GRP0 STA GRP1 STA PF0 STA PF1 STA PF2 LDA #2 STA VSYNC STA WSYNC ; for up and down, we INC or DEC ; the Y Position LDA #010000 ;Down? BIT SWCHA BNE SkipMoveDown INC YPosFromBot INC YPosFromBotE1 INC YPosFromBotE1 SkipMoveDown LDA #100000 ;Up? BIT SWCHA BNE SkipMoveUp DEC YPosFromBot DEC YPosFromBotE1 DEC YPosFromBotE1 SkipMoveUp ; for left and right, we're gonna ; set the horizontal speed, and then do ; a single HMOVE. We'll use X to hold the ; horizontal speed, then store it in the ; appropriate register ;assum horiz speed will be zero LDX #0 LDA #%01000000 ;Left? BIT SWCHA BNE SkipMoveLeft LDX #$10 ;a 1 in the left nibble means go left ;; moving left, so we need the mirror image LDA #001000 ;a 1 in D3 of REFP0 says make it mirror STA REFP0 STA REFP1 SkipMoveLeft LDA #%10000000 ;Right? BIT SWCHA BNE SkipMoveRight LDX #$F0 ;a -1 in the left nibble means go right... ;; moving right, cancel any mirrorimage LDA #000000 STA REFP0 STA REFP1 SkipMoveRight STX HMP0 ;set the move for player 0, not the missile like last time... STX HMP1 ;set the move for player 0, not the missile like last time... ; see if player and missile collide, and change the background color if so ;just a review...comparisons of numbers always seem a little backwards to me, ;since it's easier to load up the accumulator with the test value, and then ;compare that value to what's in the register we're interested. ;in this case, we want to see if D7 of CXM1P (meaning Player 0 hit ; missile 1) is on. So we put 10000000 into the Accumulator, ;then use BIT to compare it to the value in CXM1P LDA #%10000000 BIT CXM1P BEQ NoCollision ;skip if not hitting... LDA YPosFromBot ;must be a hit! load in the YPos... STA COLUBK ;and store as the bgcolor NoCollision STA CXCLR ;reset the collision detection for next time STA WSYNC ;////////////////////////////////////////////// ;setup pic animations ---------------------------------------------- INC ROLLING_COUNTER LDA ROLLING_COUNTER AND #15 ;every 8th screen swap to next image of player CMP #8 BEQ PICSET4 JMP PICSET3 PICSET4 LDA PICS CMP #8 BEQ PICSET LDA #8 JMP PICSET2 PICSET LDA #0 PICSET2 STA PICS PICSET3 LDA ROLLING_COUNTER AND #25 ;how often to move enemy, larger number is slower CMP #8 BEQ PICSET5 LDA #001111 ; +1 in the left nibble JMP PICSET6 PICSET5 LDA #011111 ; 0 in the left nibble PICSET6 STA HMP1 ; of HMP1 sets it to moving the enemy LDA #8 CLC ADC PICS ;add value of pics to Accumulator STA VisibleEnemyLineCurrent LDA #8 CLC ADC PICS ;add value of pics to Accumulator STA VisiblePlayerLineCurrent ;setup pic animations ---------------------------------------------- STA WSYNC ;////////////////////////////////////////////// LDA #43 STA TIM64T LDA #0 STA VSYNC ;------------------------- setup backgrounds 20 pixels accross LDA #255 ; 3 cycles STA PF0 ; 3 cycles STA PF1 ; 3 cycles STA PF2 ; 3 cycles ;------------------------- WaitForVblankEnd LDA INTIM BNE WaitForVblankEnd LDY #4 ; was 191 STA WSYNC STA HMOVE STA VBLANK ;main scanline loop... PreScanLoop ScanLoop1 ;start of kernal +++++++++++++++++++++++ for skyline LDA PFCOLOR-1,Y ; 4 cycles STA COLUBK ;and store as the bgcolor ; 3 cycles LDA PFData0-1,Y ; 4 cycles STA PF0 ; 3 cycles LDA PFData1-1,Y ; 4 cycles STA RESM0 ; 3 cycles places left scan line leftmost STA PF1 ; 3 cycles LDA PFData2-1,Y ; 4 cycles STA PF2 ; 3 cycles LDA #0 ;2 cycles =30 STA GRP1 ; put player 1 into grp1 3 cycles STA GRP0 ;put that line as player graphic 0 ;3 cycles =28 DEY ;count down number of scan lines 2 cycles =71 STA WSYNC ;3 cycles =74 BNE ScanLoop1 ;2 cycles =76 EndScanLoop1 ;end of kernal +++++++++++++++++++++++ for skyline LDA #100; STA COLUBK ;and store as the bgcolor LDY #186 ; was 191 was 186 LDA #0 STA PF0 ; 3 cycles STA PF1 ; 3 cycles STA PF2 ; 3 cycles LDA #%11100011 ;The last 3 bits control number and size of players ;the firs 3 bits control missle size STA NUSIZ0 STA NUSIZ1 STA WSYNC ;3 cycles ScanLoop ;start of kernal +++++++++++++++++++++++ for players ;-------------------------- y register is the line number currently being drawn ; SPRITE DRAW tya ; 2 Transfers the byte in the Y Register to the Accumulator. sec ; 2 Sets the carry (C) flag (in the processor Status Register byte). sbc YPosFromBot ; 3 Subtracts a byte in memory from the byte in the Accumulator, and "borrows" if necessary. adc #8 ; 2 Adds byte in memory to the byte in the Accumulator, plus the carry flag if set. bcs .Draw ; 2(3) Branches up to 127 bytes forward or 128 bytes backward from its own address if the carry flag is set. nop ; 2 Wait nop ; 2 Wait sec ; 2 Sets the carry (C) flag lda MainPlayerGraphics,y ; 5 Loads the Accumulator with a byte from memory. bcs .skipDraw ; 3 Branches up to 127 bytes forward or 128 bytes backward from its own address if the carry flag is set. .Draw sta GRP0 ; 3 Stores the byte in the Accumulator into memory. .skipDraw ;-->18 cycles used ;-------------------------- skipDrawRight ; 3 from BCC LDA #0 ; 2 BEQ continueRight ; 3 Return... ; STA GRP0 ;set player graphics 3 cycles ; STA GRP1 ;set player graphics 3 cycles TXA ; 2 A-> Current scannline SEC ; 2 Set Carry SBC YPosFromBot ; 3 ADC #8 ; 2 calc if sprite is drawn BCC skipDrawRight ; 2/3 To skip or not to skip? TAY ; 2 lda P1Graphic,y ; 4 continueRight: STA GRP0 DEY ;count down number of scan lines 2 cycles = STA WSYNC ;3 cycles = BNE ScanLoop ;2 cycles = EndScanLoop ;end of kernal +++++++++++++++++ for players STA WSYNC STA VBLANK LDX #24 OverScanWait STA WSYNC DEX BNE OverScanWait JMP MainLoop MainPlayerGraphics .byte #010100 .byte #010100 .byte #011000 .byte #011000 .byte #%01111110 .byte #010000 .byte #111000 .byte #111000 SpriteEnd .byte #100010 .byte #100100 .byte #101000 .byte #011000 .byte #%01111110 .byte #010000 .byte #111000 .byte #111000 EnemyGraphics .byte #%01111000 .byte #%10000100 .byte #001000 .byte #010000 .byte #010000 .byte #010000 .byte #111000 .byte #111000 .byte #%01111000 .byte #%01001000 .byte #010000 .byte #100000 .byte #100000 .byte #100000 .byte #%01110000 .byte #%01110000 PFData0 .byte #001111 .byte #011111 .byte #%01111111 .byte #%11111111 PFData1 .byte #000000 .byte #001110 .byte #111111 .byte #%01111111 PFData2 .byte #000000 .byte #011000 .byte #%10111100 .byte #%11111111 PFCOLOR .byte #$5F .byte #$5D .byte #$5B .byte #$59 org $FFFC .word Start .word Start

I tried to adapt this code to use skipdraw. However the graphics are not correct. The sprite starts in the correct location, however it seems to scroll through the memory, until you're on a certain y position. Then the graphics continue to the bottom of the screen. My code is below. processor 6502 include vcs.h org $F000 ;Variables ------ YPosFromBot = $80; VisiblePlayerLine = $81; PICS = $82; ROLLING_COUNTER = $83; Graphics_Buffer = $84 YPosFromBotE1 = $85; VisibleEnemyLine = $86; VisibleEnemyLineCurrent = $87; EnemyLineBuffer = $88; VisiblePlayerLineCurrent = $90; BG_0 = $91; BG_1 = $92; BG_2 = $93; ; Constants ------ playerheight ds #8; ;generic start up stuff... Start SEI CLD LDX #$FF TXS LDA #0 STA ROLLING_COUNTER STA PICS STA EnemyLineBuffer ClearMem STA 0,X DEX BNE ClearMem LDA #$00 ;start with a black background STA COLUBK LDA #$1C ;lets go for bright yellow, the traditional color for happyfaces STA COLUP0 ;Setting some variables... LDA #80 STA YPosFromBot ;Initial Y Position STA YPosFromBotE1 LDA #010001 ; 2 cycles STA BG_0 ; 3 cycles STA BG_1 ; 3 cycles STA BG_2 ; 3 cycles ;; Let's set up the sweeping line. as Missile 1 LDA #2 ; STA ENAM1 ;enable it LDA #33 STA COLUP0 ;color it STA COLUP1 ;color it LDA #$10 ; STA NUSIZ0 ;make it quadwidth (not so thin, that) STA NUSIZ1 ;make it quadwidth (not so thin, that) LDA #000000 ; set to not move STA HMM1 ; of HMM1 sets it to moving ;VSYNC time MainLoop ;+++++++++++++++++++++++++++The start of a new screen LDA #0 STA GRP0 STA GRP1 STA PF0 STA PF1 STA PF2 LDA #2 STA VSYNC STA WSYNC ; for up and down, we INC or DEC ; the Y Position LDA #010000 ;Down? BIT SWCHA BNE SkipMoveDown INC YPosFromBot INC YPosFromBotE1 INC YPosFromBotE1 SkipMoveDown LDA #100000 ;Up? BIT SWCHA BNE SkipMoveUp DEC YPosFromBot DEC YPosFromBotE1 DEC YPosFromBotE1 SkipMoveUp ; for left and right, we're gonna ; set the horizontal speed, and then do ; a single HMOVE. We'll use X to hold the ; horizontal speed, then store it in the ; appropriate register ;assum horiz speed will be zero LDX #0 LDA #%01000000 ;Left? BIT SWCHA BNE SkipMoveLeft LDX #$10 ;a 1 in the left nibble means go left ;; moving left, so we need the mirror image LDA #001000 ;a 1 in D3 of REFP0 says make it mirror STA REFP0 STA REFP1 SkipMoveLeft LDA #%10000000 ;Right? BIT SWCHA BNE SkipMoveRight LDX #$F0 ;a -1 in the left nibble means go right... ;; moving right, cancel any mirrorimage LDA #000000 STA REFP0 STA REFP1 SkipMoveRight STX HMP0 ;set the move for player 0, not the missile like last time... STX HMP1 ;set the move for player 0, not the missile like last time... ; see if player and missile collide, and change the background color if so ;just a review...comparisons of numbers always seem a little backwards to me, ;since it's easier to load up the accumulator with the test value, and then ;compare that value to what's in the register we're interested. ;in this case, we want to see if D7 of CXM1P (meaning Player 0 hit ; missile 1) is on. So we put 10000000 into the Accumulator, ;then use BIT to compare it to the value in CXM1P LDA #%10000000 BIT CXM1P BEQ NoCollision ;skip if not hitting... LDA YPosFromBot ;must be a hit! load in the YPos... STA COLUBK ;and store as the bgcolor NoCollision STA CXCLR ;reset the collision detection for next time STA WSYNC ;////////////////////////////////////////////// ;setup pic animations ---------------------------------------------- INC ROLLING_COUNTER LDA ROLLING_COUNTER AND #15 ;every 8th screen swap to next image of player CMP #8 BEQ PICSET4 JMP PICSET3 PICSET4 LDA PICS CMP #8 BEQ PICSET LDA #8 JMP PICSET2 PICSET LDA #0 PICSET2 STA PICS PICSET3 LDA ROLLING_COUNTER AND #25 ;how often to move enemy, larger number is slower CMP #8 BEQ PICSET5 LDA #001111 ; +1 in the left nibble JMP PICSET6 PICSET5 LDA #011111 ; 0 in the left nibble PICSET6 STA HMP1 ; of HMP1 sets it to moving the enemy LDA #8 CLC ADC PICS ;add value of pics to Accumulator STA VisibleEnemyLineCurrent LDA #8 CLC ADC PICS ;add value of pics to Accumulator STA VisiblePlayerLineCurrent ;setup pic animations ---------------------------------------------- STA WSYNC ;////////////////////////////////////////////// LDA #43 STA TIM64T LDA #0 STA VSYNC ;------------------------- setup backgrounds 20 pixels accross LDA #255 ; 3 cycles STA PF0 ; 3 cycles STA PF1 ; 3 cycles STA PF2 ; 3 cycles ;------------------------- WaitForVblankEnd LDA INTIM BNE WaitForVblankEnd LDY #4 ; was 191 STA WSYNC STA HMOVE STA VBLANK ;main scanline loop... PreScanLoop ScanLoop1 ;start of kernal +++++++++++++++++++++++ for skyline LDA PFCOLOR-1,Y ; 4 cycles STA COLUBK ;and store as the bgcolor ; 3 cycles LDA PFData0-1,Y ; 4 cycles STA PF0 ; 3 cycles LDA PFData1-1,Y ; 4 cycles STA RESM0 ; 3 cycles places left scan line leftmost STA PF1 ; 3 cycles LDA PFData2-1,Y ; 4 cycles STA PF2 ; 3 cycles LDA #0 ;2 cycles =30 STA GRP1 ; put player 1 into grp1 3 cycles STA GRP0 ;put that line as player graphic 0 ;3 cycles =28 DEY ;count down number of scan lines 2 cycles =71 STA WSYNC ;3 cycles =74 BNE ScanLoop1 ;2 cycles =76 EndScanLoop1 ;end of kernal +++++++++++++++++++++++ for skyline LDA #100; STA COLUBK ;and store as the bgcolor LDY #186 ; was 191 was 186 LDA #0 STA PF0 ; 3 cycles STA PF1 ; 3 cycles STA PF2 ; 3 cycles LDA #%11100011 ;The last 3 bits control number and size of players ;the firs 3 bits control missle size STA NUSIZ0 STA NUSIZ1 STA WSYNC ;3 cycles ScanLoop ;start of kernal +++++++++++++++++++++++ for players ;-------------------------- y register is the line number currently being drawn ; SPRITE DRAW tya ; 2 Transfers the byte in the Y Register to the Accumulator. sec ; 2 Sets the carry (C) flag (in the processor Status Register byte). sbc YPosFromBot ; 3 Subtracts a byte in memory from the byte in the Accumulator, and "borrows" if necessary. adc #8 ; 2 Adds byte in memory to the byte in the Accumulator, plus the carry flag if set. bcs .Draw ; 2(3) Branches up to 127 bytes forward or 128 bytes backward from its own address if the carry flag is set. nop ; 2 Wait nop ; 2 Wait sec ; 2 Sets the carry (C) flag bcs .skipDraw ; 3 Branches up to 127 bytes forward or 128 bytes backward from its own address if the carry flag is set. .Draw lda MainPlayerGraphics,y ; 5 Loads the Accumulator with a byte from memory. sta GRP0 ; 3 Stores the byte in the Accumulator into memory. .skipDraw ;-->18 cycles used ;-------------------------- ; STA GRP0 ;set player graphics 3 cycles ; STA GRP1 ;set player graphics 3 cycles DEY ;count down number of scan lines 2 cycles = STA WSYNC ;3 cycles = BNE ScanLoop ;2 cycles = EndScanLoop ;end of kernal +++++++++++++++++ for players STA WSYNC STA VBLANK LDX #24 OverScanWait STA WSYNC DEX BNE OverScanWait JMP MainLoop MainPlayerGraphics .byte #010100 .byte #010100 .byte #011000 .byte #011000 .byte #%01111110 .byte #010000 .byte #111000 .byte #111000 SpriteEnd .byte #100010 .byte #100100 .byte #101000 .byte #011000 .byte #%01111110 .byte #010000 .byte #111000 .byte #111000 EnemyGraphics .byte #%01111000 .byte #%10000100 .byte #001000 .byte #010000 .byte #010000 .byte #010000 .byte #111000 .byte #111000 .byte #%01111000 .byte #%01001000 .byte #010000 .byte #100000 .byte #100000 .byte #100000 .byte #%01110000 .byte #%01110000 PFData0 .byte #001111 .byte #011111 .byte #%01111111 .byte #%11111111 PFData1 .byte #000000 .byte #001110 .byte #111111 .byte #%01111111 PFData2 .byte #000000 .byte #011000 .byte #%10111100 .byte #%11111111 PFCOLOR .byte #$5F .byte #$5D .byte #$5B .byte #$59 org $FFFC .word Start .word Start

I'm trying to convert this code to use skipdraw. However so far the graphics aren't correct. What am I doing wrong? ; move a happy face with the joystick by Kirk Israel ; (with a can't'dodge'em line sweeping across the screen) processor 6502 include vcs.h org $F000 ;Variables ------ YPosFromBot = $80; VisiblePlayerLine = $81; PICS = $82; ROLLING_COUNTER = $83; Graphics_Buffer = $84 YPosFromBotE1 = $85; VisibleEnemyLine = $86; VisibleEnemyLineCurrent = $87; EnemyLineBuffer = $88; VisiblePlayerLineCurrent = $90; BG_0 = $91; BG_1 = $92; BG_2 = $93; ; Constants ------ playerheight ds #8; ;generic start up stuff... Start SEI CLD LDX #$FF TXS LDA #0 STA ROLLING_COUNTER STA PICS STA EnemyLineBuffer ClearMem STA 0,X DEX BNE ClearMem LDA #$00 ;start with a black background STA COLUBK LDA #$1C ;lets go for bright yellow, the traditional color for happyfaces STA COLUP0 ;Setting some variables... LDA #80 STA YPosFromBot ;Initial Y Position STA YPosFromBotE1 LDA #010001 ; 2 cycles STA BG_0 ; 3 cycles STA BG_1 ; 3 cycles STA BG_2 ; 3 cycles ;; Let's set up the sweeping line. as Missile 1 LDA #2 ; STA ENAM1 ;enable it LDA #33 STA COLUP0 ;color it STA COLUP1 ;color it LDA #$10 ; STA NUSIZ0 ;make it quadwidth (not so thin, that) STA NUSIZ1 ;make it quadwidth (not so thin, that) LDA #000000 ; set to not move STA HMM1 ; of HMM1 sets it to moving ;VSYNC time MainLoop ;+++++++++++++++++++++++++++The start of a new screen LDA #0 STA GRP0 STA GRP1 STA PF0 STA PF1 STA PF2 LDA #2 STA VSYNC STA WSYNC ; for up and down, we INC or DEC ; the Y Position LDA #010000 ;Down? BIT SWCHA BNE SkipMoveDown INC YPosFromBot INC YPosFromBotE1 INC YPosFromBotE1 SkipMoveDown LDA #100000 ;Up? BIT SWCHA BNE SkipMoveUp DEC YPosFromBot DEC YPosFromBotE1 DEC YPosFromBotE1 SkipMoveUp ; for left and right, we're gonna ; set the horizontal speed, and then do ; a single HMOVE. We'll use X to hold the ; horizontal speed, then store it in the ; appropriate register ;assum horiz speed will be zero LDX #0 LDA #%01000000 ;Left? BIT SWCHA BNE SkipMoveLeft LDX #$10 ;a 1 in the left nibble means go left ;; moving left, so we need the mirror image LDA #001000 ;a 1 in D3 of REFP0 says make it mirror STA REFP0 STA REFP1 SkipMoveLeft LDA #%10000000 ;Right? BIT SWCHA BNE SkipMoveRight LDX #$F0 ;a -1 in the left nibble means go right... ;; moving right, cancel any mirrorimage LDA #000000 STA REFP0 STA REFP1 SkipMoveRight STX HMP0 ;set the move for player 0, not the missile like last time... STX HMP1 ;set the move for player 0, not the missile like last time... ; see if player and missile collide, and change the background color if so ;just a review...comparisons of numbers always seem a little backwards to me, ;since it's easier to load up the accumulator with the test value, and then ;compare that value to what's in the register we're interested. ;in this case, we want to see if D7 of CXM1P (meaning Player 0 hit ; missile 1) is on. So we put 10000000 into the Accumulator, ;then use BIT to compare it to the value in CXM1P LDA #%10000000 BIT CXM1P BEQ NoCollision ;skip if not hitting... LDA YPosFromBot ;must be a hit! load in the YPos... STA COLUBK ;and store as the bgcolor NoCollision STA CXCLR ;reset the collision detection for next time STA WSYNC ;////////////////////////////////////////////// ;setup pic animations ---------------------------------------------- INC ROLLING_COUNTER LDA ROLLING_COUNTER AND #15 ;every 8th screen swap to next image of player CMP #8 BEQ PICSET4 JMP PICSET3 PICSET4 LDA PICS CMP #8 BEQ PICSET LDA #8 JMP PICSET2 PICSET LDA #0 PICSET2 STA PICS PICSET3 LDA ROLLING_COUNTER AND #25 ;how often to move enemy, larger number is slower CMP #8 BEQ PICSET5 LDA #001111 ; +1 in the left nibble JMP PICSET6 PICSET5 LDA #011111 ; 0 in the left nibble PICSET6 STA HMP1 ; of HMP1 sets it to moving the enemy LDA #8 CLC ADC PICS ;add value of pics to Accumulator STA VisibleEnemyLineCurrent LDA #8 CLC ADC PICS ;add value of pics to Accumulator STA VisiblePlayerLineCurrent ;setup pic animations ---------------------------------------------- STA WSYNC ;////////////////////////////////////////////// LDA #43 STA TIM64T LDA #0 STA VSYNC ;------------------------- setup backgrounds 20 pixels accross LDA #255 ; 3 cycles STA PF0 ; 3 cycles STA PF1 ; 3 cycles STA PF2 ; 3 cycles ;------------------------- WaitForVblankEnd LDA INTIM BNE WaitForVblankEnd LDY #4 ; was 191 STA WSYNC STA HMOVE STA VBLANK ;main scanline loop... PreScanLoop ScanLoop1 ;start of kernal +++++++++++++++++++++++ for skyline LDA PFCOLOR-1,Y ; 4 cycles STA COLUBK ;and store as the bgcolor ; 3 cycles LDA PFData0-1,Y ; 4 cycles STA PF0 ; 3 cycles LDA PFData1-1,Y ; 4 cycles STA RESM0 ; 3 cycles places left scan line leftmost STA PF1 ; 3 cycles LDA PFData2-1,Y ; 4 cycles STA PF2 ; 3 cycles LDA #0 ;2 cycles =30 STA GRP1 ; put player 1 into grp1 3 cycles STA GRP0 ;put that line as player graphic 0 ;3 cycles =28 DEY ;count down number of scan lines 2 cycles =71 STA WSYNC ;3 cycles =74 BNE ScanLoop1 ;2 cycles =76 EndScanLoop1 ;end of kernal +++++++++++++++++++++++ for skyline LDA #100; STA COLUBK ;and store as the bgcolor LDY #186 ; was 191 was 186 LDA #0 STA PF0 ; 3 cycles STA PF1 ; 3 cycles STA PF2 ; 3 cycles LDA #%11100011 ;The last 3 bits control number and size of players ;the firs 3 bits control missle size STA NUSIZ0 STA NUSIZ1 STA WSYNC ;3 cycles ScanLoop ;start of kernal +++++++++++++++++++++++ for players ;-------------------------- ; SPRITE DRAW tya ; 2 Transfers the byte in the Y Register to the Accumulator. sec ; 2 Sets the carry (C) flag (in the processor Status Register byte). sbc SpriteEnd ; 3 Subtracts a byte in memory from the byte in the Accumulator, and "borrows" if necessary. adc #8 ; 2 Adds byte in memory to the byte in the Accumulator, plus the carry flag if set. bcs .Draw ; 2(3) Branches up to 127 bytes forward or 128 bytes backward from its own address if the carry flag is set. nop ; 2 Wait nop ; 2 Wait sec ; 2 Sets the carry (C) flag bcs .skipDraw ; 3 Branches up to 127 bytes forward or 128 bytes backward from its own address if the carry flag is set. .Draw lda MainPlayerGraphics,y ; 5 Loads the Accumulator with a byte from memory. sta GRP0 ; 3 Stores the byte in the Accumulator into memory. .skipDraw ;-->18 cycles used ;-------------------------- STA GRP0 ;set player graphics 3 cycles STA GRP1 ;set player graphics 3 cycles DEY ;count down number of scan lines 2 cycles = STA WSYNC ;3 cycles = BNE ScanLoop ;2 cycles = EndScanLoop ;end of kernal +++++++++++++++++ for players STA WSYNC STA VBLANK LDX #24 OverScanWait STA WSYNC DEX BNE OverScanWait JMP MainLoop MainPlayerGraphics .byte #010100 .byte #010100 .byte #011000 .byte #011000 .byte #%01111110 .byte #010000 .byte #111000 .byte #111000 SpriteEnd .byte #100010 .byte #100100 .byte #101000 .byte #011000 .byte #%01111110 .byte #010000 .byte #111000 .byte #111000 EnemyGraphics .byte #%01111000 .byte #%10000100 .byte #001000 .byte #010000 .byte #010000 .byte #010000 .byte #111000 .byte #111000 .byte #%01111000 .byte #%01001000 .byte #010000 .byte #100000 .byte #100000 .byte #100000 .byte #%01110000 .byte #%01110000 PFData0 .byte #001111 .byte #011111 .byte #%01111111 .byte #%11111111 PFData1 .byte #000000 .byte #001110 .byte #111111 .byte #%01111111 PFData2 .byte #000000 .byte #011000 .byte #%10111100 .byte #%11111111 PFCOLOR .byte #$5F .byte #$5D .byte #$5B .byte #$59 org $FFFC .word Start .word Start

I just bought one for 40 with phaser patrol and fireball. I overpaid a little. I was mad for having missed that auction that went for 16. There's a CIB one on ebay for 35. 18 is not bad, just make sure that when they modded it, they didn't damage the whole thing. I recieved my supercharger yesterday, but I misplaced my cassette player, and haven't gotten to use it yet.

Here is a thread about spasticolour http://www.atariage.com/forums/topic/62704-flicker-free-large-sprites-sample-mpg/

What games require a second controller, like Riddle of the Sphinx? In that game the second controller chooses which item you want to use. Did Space Shuttle require the second stick?

Was the atari 2800 ever sold in the US?