;--------------------------------------------------------------------------- ; * Subject: [stella] Christmas program ; * From: Piero Cavina ; * Date: Thu, 25 Dec 1997 23:28:47 +0100 ; * Reply-To: stella@biglist.com ;--------------------------------------------------------------------------- ; chrdem01.asm ; Piero Cavina's "it's Christmas and I can't leave my 2600 alone demo v 0.1" ; 25/12/1997 processor 6502 VSYNC = $00 VBLANK = $01 WSYNC = $02 NUSIZ0 = $04 NUSIZ1 = $05 COLUP0 = $06 COLUP1 = $07 COLUPF = $08 COLUBK = $09 CTRLPF = $0A REFP0 = $0B REFP1 = $0C PF0 = $0D PF1 = $0E PF2 = $0F RESP0 = $10 RESP1 = $11 RESM0 = $12 RESM1 = $13 RESBL = $14 AUDC0 = $15 AUDF0 = $17 AUDV0 = $19 AUDC1 = $16 AUDF1 = $18 AUDV1 = $1A GRP0 = $1B GRP1 = $1C ENAM0 = $1D ENAM1 = $1E ENABL = $1F HMP0 = $20 HMP1 = $21 HMM0 = $22 HMM1 = $23 HMBL = $24 RESMP0 = $28 RESMP1 = $29 HMOVE = $2A HMCLR = $2B CXCLR = $2C CXM0P = $30 CXP1FB = $33 SWCHA = $0280 SWACNT = $0281 SWCHB = $0282 SWBCNT = $0283 INTIM = $0284 TIM8T = $0295 TIM64T = $0296 CXPPMM = $7 INPT0 = $8 INPT3 = $A INPT4 = $3C COUNT = $80 ORG $F000 CLD LDX #$FF TXS INX TXA LPC: STA VSYNC,X INX BNE LPC STA SWBCNT STA SWACNT MAIN: LDX #0 LDA #$02 STA WSYNC STA WSYNC STA WSYNC STA VSYNC STA WSYNC STA WSYNC STA WSYNC STX VSYNC ; ------------------------- LDA #$35 STA TIM64T ; ------------------------- STA WSYNC LDX #7 LPP: DEX BPL LPP STA RESM1 STA RESM0 ; ------------------------- ; Finisici il tempo di Vblank LF20C: LDA INTIM BNE LF20C STA WSYNC STA VBLANK STA HMCLR ; ------------------------- ; Kernel LDA #$FF STA ENAM1 STA ENAM0 INC COUNT ; try to uncomment these lines.. ; LDA COUNT ; STA NUSIZ0 ; STA NUSIZ1 LDX #191 LK: TXA ADC COUNT ASL ASL STA HMM1 EOR #$FF STA HMM0 STA COLUP1 STA COLUP0 STA WSYNC STA HMOVE DEX BNE LK ; ------------------------- STX ENAM1 STX ENAM0 STA WSYNC LDA #$02 STA WSYNC STA VBLANK ; ------------------------- LDA #$2A STA TIM64T ; ------------------------ OVRS: LDA INTIM BNE OVRS JMP MAIN ORG $FFFC .byte $00,$F0,$00,$F0