C64 16x16 char matrix plot routine + sinus generator

gistfile1.txt

;create the 16x16 char matrix
MAKESRC
         LDX #$00
         LDA #$00
         CLC
LOOP     TAY
         STA $0400+(40*5+12),X
         ADC #1
         STA $0400+(40*6+12),X
         ADC #1
         STA $0400+(40*7+12),X
         ADC #1
         STA $0400+(40*8+12),X
         ADC #1
         STA $0400+(40*9+12),X
         ADC #1
         STA $0400+(40*10+12),X
         ADC #1
         STA $0400+(40*11+12),X
         ADC #1
         STA $0400+(40*12+12),X
         ADC #1
         STA $0400+(40*13+12),X
         ADC #1
         STA $0400+(40*14+12),X
         ADC #1
         STA $0400+(40*15+12),X
         ADC #1
         STA $0400+(40*16+12),X
         ADC #1
         STA $0400+(40*17+12),X
         ADC #1
         STA $0400+(40*18+12),X
         ADC #1
         STA $0400+(40*19+12),X
         ADC #1
         STA $0400+(40*20+12),X
         TYA
         ADC #16
         INX
         CPX #$10
         BNE LOOP
         RTS

; set a dot at x/y... to the char ram at $2000
PLOT
         ;LDX #0
         ;LDY #0
         LDA XTAB,X
         STA 58
         LDA YTAB,X
         STA 59
         LDA (58),Y
         ORA BMP,X
         STA (58),Y
         RTS
         
XTAB     .BYTE 0,0,0,0,0,0,0,0
         .BYTE $80,$80,$80,$80,$80,$80
         .BYTE $80,$80
         .BYTE 0,0,0,0,0,0,0,0
         .BYTE $80,$80,$80,$80,$80,$80
         .BYTE $80,$80
         .BYTE 0,0,0,0,0,0,0,0
         .BYTE $80,$80,$80,$80,$80,$80
         .BYTE $80,$80
         .BYTE 0,0,0,0,0,0,0,0
         .BYTE $80,$80,$80,$80,$80,$80
         .BYTE $80,$80
         .BYTE 0,0,0,0,0,0,0,0
         .BYTE $80,$80,$80,$80,$80,$80
         .BYTE $80,$80
         .BYTE 0,0,0,0,0,0,0,0
         .BYTE $80,$80,$80,$80,$80,$80
         .BYTE $80,$80
         .BYTE 0,0,0,0,0,0,0,0
         .BYTE $80,$80,$80,$80,$80,$80
         .BYTE $80,$80
         .BYTE 0,0,0,0,0,0,0,0
         .BYTE $80,$80,$80,$80,$80,$80
         .BYTE $80,$80
BMP      .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
         .BYTE $80,$40,$20,$10,$08,$04
         .BYTE $02,$01
YTAB     .BYTE $20,$20,$20,$20,$20,$20
         .BYTE $20,$20,$20,$20,$20,$20
         .BYTE $20,$20,$20,$20,$21,$21
         .BYTE $21,$21,$21,$21,$21,$21
         .BYTE $21,$21,$21,$21,$21,$21
         .BYTE $21,$21,$22,$22,$22,$22
         .BYTE $22,$22,$22,$22,$22,$22
         .BYTE $22,$22,$22,$22,$22,$22
         .BYTE $23,$23,$23,$23,$23,$23
         .BYTE $23,$23,$23,$23,$23,$23
         .BYTE $23,$23,$23,$23,$24,$24
         .BYTE $24,$24,$24,$24,$24,$24
         .BYTE $24,$24,$24,$24,$24,$24
         .BYTE $24,$24,$25,$25,$25,$25
         .BYTE $25,$25,$25,$25,$25,$25
         .BYTE $25,$25,$25,$25,$25,$25
         .BYTE $26,$26,$26,$26,$26,$26
         .BYTE $26,$26,$26,$26,$26,$26
         .BYTE $26,$26,$26,$26,$27,$27
         .BYTE $27,$27,$27,$27,$27,$27
         .BYTE $27,$27,$27,$27,$27,$27
         .BYTE $27,$27

; generates a rough sinus wave at $3000
SINGEN
         LDY #$3F
         LDX #$00
         STX $E0
         STX $E1
         STX $E2
SGLOOP   INC $0E
         LDA $0E
         ASL A
         ASL A
         ADC $E1
         STA $E1
         LDA $E2
         ADC #$00
         STA $E2
         ASL A
         STA $3080,Y
         STA $30C0,X
         LSR A
         EOR #$3F
         ASL A
         STA $3000,Y
         STA $3040,X
         INX
         DEY
         BPL SGLOOP
         RTS