Subject: [stella] New questions From: John K Harvey <jkharvey@xxxxxxxxxxxxxxxxx> Date: Tue, 22 Sep 1998 12:42:10 -0500 |
Ok, I have some interesting new questions. 1) Why must that DEX thing be at the end of the Kill loop in order to draw a playfield? 2) Why is my playfield always black (it is on the sides of the screen. Difficult to see, but it is there) 3)In regards to sound, when I delete the ; before the BNE, it doesn't give me the effect I want, which is a glissando thru all the frequency values. Is it going too fast? Have I forgot something? -John K. Harvey Source code: processor 6502 include vcs.h ORG $F000 START: CLD SEI LDX #$FF LDA #0 B1: STA 0,X DEX BNE B1 MAIN: LDX #0 LDA #2 STA WSYNC STA WSYNC STA WSYNC STA VSYNC STA WSYNC STA WSYNC LDA #44 STA TIM64T LDA #0 STA CXCLR STA WSYNC STA VSYNC DRAW: LDA INTIM BNE DRAW STA WSYNC STA VBLANK LDA #3 STA CTRLPF LDY #191 LDX #239 LOOPER: TYA LDA #8 STX COLUBK DEX DEX CPX #$F BNE FISH; If colors are that ugly black or that repeating brown, skip LDX #239; (255-16) FISH: STA WSYNC; draws one line DEY BNE LOOPER LDA #2 STA WSYNC STA VBLANK LDA #32; playfield stuff? Why won't you work? STA COLUPF LDA #$10 STA PF0 LDA #10 STA AUDV0 STA AUDC0 LDX #10 FOO: STX AUDF0 INX CPX #31 ;BNE FOO;when uncommented, it makes a terrible noise. KILL: STA WSYNC DEX ; Why must this be here in order to draw a playfield? BNE KILL JMP MAIN ORG $FFFC .word START .word START -- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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