Commodore64 C64 SPRITE SCROLLER IN BORDER

I got side border version out • C64 COED BAKERY sprite...
Source Code here:
www.lemon64.co...
As doublewide sprite is 48pixel, I slice up the work in small snippets spaced out over 48frames, so no workload spikes.
jumptable
WORD sprsetup, color, skip, skip ; 1-4
WORD skip, color, skip, skip ; 5-8
WORD gettext1, color, skip, skip ; 9-12
WORD gettext2, color, skip, skip ; 13-16
WORD gettext3, color, skip, skip ; 17-20
WORD copyfonts, color, skip, skip ; 21-24
WORD skip, color, skip, skip ; 25-28
WORD skip, color, skip, removmsb ; 29-32
WORD skip, color, skip, skip ; 33-36
WORD skip, color, skip, skip ; 37-40
WORD skip, color, skip, skip ; 41-44
WORD skip, color, skip, addmsb ; 45-48

[@tonysofla]

More advanced version: kzbin.info/www/bejne/naDNp5RjnLqAjqc

[@MiccaPhone]

A Sprit SCOLLER without an "R" :-D

[@tonysofla]

I noticed it too, after I uploaded it.

[@dr.ignacioglez.9677]

I REALLY LOVE C64 👍🥂🎩

[@cbmeeks]

Pretty awesome. Where did you get that music? I've been hearing it a lot in Commodore related videos (even a CoCo one too).

[@tonysofla]

KZbin library, I searched 8bit

[@CoolDudeClem]

The only thing this video needs is a SID rendition of the music.

[@drlegendre]

Nifty!

[@JustWasted3HoursHere]

As Robin from "8 Bit Show & tell" said recently, removing the top and bottom borders is tricky but fairly doable by most people if they're careful. But removing the side borders - without glitches - is VERY tricky because timing must not only be exact but it must accommodate actions that can cause extra or fewer cycles to throw a wrench in the timing. I don't think I've ever seen even a demo remove ALL borders with anything consequential happening on the screen.

[@tonysofla]

If you look at my lemon64 link, I was able to open sideborder too in last post, first you need stable raster, I used double irq to get from 0-7cycle jitter down to 0-1 jitter with nop's and finaly 0 jitter by checking raster line.

[@tonysofla]

postimg.cc/0KdGXBP1

[@JustWasted3HoursHere]

@@tonysofla It is quite tricky though, especially if you have changing sprite characteristics that can change how many cycles the VIC is using on the fly. Very impressive though!

[@DavidSpitzerLawDog]

Cool scoller

[@meneerjansen00]

This looks really cool! Maybe one can scroll the latest news or the weather forecast whilst programming in BASIC. Would be insanely slow, I think but during the typing in of code, why not? 😃 Come to think of it, how you stop the prog to go on with other things C64? Reset the computer?

[@tonysofla]

FRAME 32, this had to be done exact here as sprite7 starts with a x value msb+31, uses a table as generate mask from sprindex would probably use more bytes. Also move out of view sprite snug against the end of the sprite-conveyer-belt removmsb LDA sprindex ; after 32 scrolls a sprite crosses below msb TAY ASL A ; double it TAX LDA #95 ; also move most left sprite STA $D000,x ; to the right side as all under border LDA $D010 AND remtable,y STA $D010 JMP taskexit remtable BYTE %10111111, %01111111, %11111110, %11111101 BYTE %11111011, %11110111, %11101111, %11011111

[@TamasKalman]

awesome video - what is the sound track pls?

[@tonysofla]

FRAME 2,6... every 4th frame, uses redundant repeated table, as having a check in inner-loop is best avoidable. color LDX #0-0 ; 0 to 7 INX CPX #8 BNE _notendcol LDX #0 _notendcol STX color+LB LDY #7 _colloop LDA colortable,x STA $D027,y ; sprite0 color + y INX DEY BPL _colloop JMP taskexit colortable BYTE 1,15,12,11,11,12,15,1 , 1,15,12,11,11,12,15 ;repeat 7 bytes

[@tonysofla]

FRAME 21 (as Sprite is now behind border out of view) copy 3 rom chars to sprite in one go, counting down is faster so do it backwards. copyfonts LDA #$33 ; make the CPU see the Character Generator ROM STA $01 ; at $D000 LDX #7 ; copy chars to sprite in one swoop LDY #23 ; 3rd column 8th row in a sprite source3 LDA $d018,x ; do this while sprite is all under border dest3 STA $3080,y DEY source2 LDA $d010,x dest2 STA $3080,y DEY source1 LDA $d008,x dest1 STA $3080,y DEY ; third dey DEX ; one dex BPL source3 ; if less than zero stop LDA #$37 ; switch in I/O mapped registers again STA $01 ; so vic can see them JMP taskexit

[@tonysofla]

FRAME 48, last frame, Sprite1 has now crossed in to negative (left side) range and need msb set, also increase sprite index first. addmsb LDA sprindex CLC ADC #1 AND #7 ; so increse sprite index 0-7 STA sprindex TAY ; backit up to y ASL A ; double it TAX ; move it to x _palfix LDA #$ff ; $f7 is equal -1 under PAL system STA $D000,x ; x-pos was a $ff value LDA $D010 ; so under ntsc nothing change ORA addtable,y ; now move the sprite to the negative range STA $D010 ; that is all the way to the left TXA JMP taskexit addtable BYTE %00000001, %00000010, %00000100, %00001000 BYTE %00010000, %00100000, %01000000, %10000000

[@tonysofla]

FRAME1: sprsetup LDA sprindex ; first entry 321 LSR A ; 00000032 (1) ROR A ; 10000003 (2) ROR A ; 21000000 (3) the 3 is used in HB STA dest1+LB ; 0, 64, 128 or 192 STA dest2+LB STA dest3+LB LDA #>sprdata ; get HB of sprite data loc ADC #0 ; use (if) carry from the 3 STA dest1+HB ; 0, 64, 128 or 192 STA dest2+HB STA dest3+HB JMP taskexit

[@tonysofla]

FRAME 9, 13, 17 (not really important where) gettext1 LDX #source1-source3 ; sprite is filled in from bottom right.. BYTE $2C ; the BIT opcode skip trick gettext2 LDX #source2-source3 ; ...to top left so source3 is first BYTE $2C gettext3 LDX #source3-source3 ; yes it would be zero _thechar LDY #0-0 ; char pointer LDA mytext,y ; get char CMP #$ff ; end of text so can use 0-to-254 petscii BNE _noendtxt ; replace these two lines w/ BPL for cbm style LDA #32 ; replace w/ space, use AND #127 for cbm style LDY #-1 ; iny below makes it 0 max 256 charters for now _noendtxt INY STY _thechar+LB ; next char on return TAY ; 87654321 ASL A ; 76543210 = x2 ASL A ; 65432100 = x4 ASL A ; 54321000 = x8 STA source3+LB,x ; store it in copyfonts 1 to 3 TYA ; 87654321 LSR A ; 08765432 LSR A ; 00876543 LSR A ; 00087654 LSR A ; 00008765 LSR A ; 00000876 ORA #$D0 ; char rom block start at $D000 STA source3+HB,x ; store it in copyfonts 1 to 3 JMP taskexit