Today I'd like to share with Commodore community this little piece I made back in the 1990-s - an IRQ sprite clock for Commodore-64.
Clock works in IRQ interrupt. Presentation is made with sprites (clock digits are mapped to sprite objects and displayed on screen). It is possible to use C-64 while this clock works. Oddly enough, this clock seems to be interfering with I/O while running on real hardware (unable to use disk drive or tape, will hung) but works fine in emulator. If you find the bug, please let me know!
; SPRITE IRQ CLOCK (C) Marek Karcz
; Code below compiles with CC65 assembler:
; cl65 --verbose --listing spriteclock.asm
; Use HEX editor to insert "00 C0" at the beginning
; of the executable to be able to run it on C64 or
; in emulator.
; Usage:
; LOAD"SPRITECLOCK",8,1
; CLR:NEW
; SYS49152,"HHMMSS"
; Where:
; HH - hours, MM - minutes, SS - seconds
; To turn the clock off:
; SYS49152
VIC = 53248 ;VIC Base
WSKSP0 = 2040 ;PTR. SPRITE 0
WSKSP1 = 2041 ;PTR. SPRITE 1
WSKSP2 = 2042 ;PTR. SPRITE 2
BLOK13 = 832 ;PTR. BEG. OF BLOCK 13
BLOK14 = 896 ;PTR. BEG. OF BLOCK 14
BLOK15 = 960 ;SEE ABOVE - BLOCK 15
IRQWKT = 788 ;IRQ VECT.
POBZNA = 121 ;READ CURR. BYTE
PRZECT = $AEFD ;CHECK COMMA
ANAWYR = 44446 ;PARSE EXPR.
POBTXT = 46978 ;GET STRING
.ORG $C000
JMP STEROW
LICZNIK: .BYTE 60 ;COUNTER
WZORCE: .BYTE 2,3,5,9,5,9 ;TEMPLATES
CZAS: .BYTE 1,2,0,0,0,0 ;TIME
LICZPOZ: .BYTE 1 ;POS. COUNTER
CYF0: .BYTE 0,252,204,204 ;DIGIT 0
.BYTE 204,204,204,252
CYF1: .BYTE 0,12,12,12 ;DIGIT 1
.BYTE 12,12,12,12
CYF2: .BYTE 0,252,12,12 ;DIGIT 2, etc...
.BYTE 252,192,192,252
CYF3: .BYTE 0,252,12,12
.BYTE 60,12,12,252
CYF4: .BYTE 0,204,204,204
.BYTE 252,12,12,12
CYF5: .BYTE 0,252,192,252
.BYTE 12,12,12,252
CYF6: .BYTE 0,252,192,192
.BYTE 252,204,204,252
CYF7: .BYTE 0,252,12,24
.BYTE 48,96,192,192
CYF8: .BYTE 0,252,204,204
.BYTE 252,204,204,252
CYF9: .BYTE 0,252,204,204
.BYTE 252,12,12,252
DWUKR: .BYTE 0,0,48,48 ;COLON
.BYTE 0,48,48,0
COPY: LDX #$00
LDY #$00
LOOP1: LDA CYF0,X
BLKNR: STA BLOK13,Y
CPX #7
BEQ POZ
INY
INY
INY
INX
JMP LOOP1
POZ: RTS
IRQROM: JMP $EA31
MAIN: DEC LICZNIK
BNE IRQROM
LDA #60
STA LICZNIK
LDA CZAS
LDX #3
CMP #2
BEQ NOC
LDX #9
NOC: STX WZORCE+1
LDX #5
NXTCYF: LDA CZAS,X
INC CZAS,X
CMP WZORCE,X
BNE KOP1
LDA #$00
STA CZAS,X
DEX
BPL NXTCYF
KOP1: LDA #$00
STA LICZPOZ
LDX #<CZAS
LDY #>CZAS
STX KOPIUJ+1
STY KOPIUJ+3
LDX #<BLOK13
LDY #>BLOK13
STX POS0B+1
STY POS0C+1
KOPIUJ: LDX #<CZAS
LDY #>CZAS
STX POS0+1
STY POS0+2
POS0: LDA CZAS
CMP #$00
BNE NIE00
LDX #<CYF0
LDY #>CYF0
POS0A: STX LOOP1+1
STY LOOP1+2
POS0B: LDX #<BLOK13
POS0C: LDY #>BLOK13
STX BLKNR+1
STY BLKNR+2
JSR COPY
JMP POS1
NIE00: CMP #$01
BNE NIE01
LDX #<CYF1
LDY #>CYF1
JMP POS0A
NIE01: CMP #$02
BNE NIE02
LDX #<CYF2
LDY #>CYF2
JMP POS0A
NIE02: CMP #$03
BNE NIE03
LDX #<CYF3
LDY #>CYF3
JMP POS0A
NIE03: CMP #$04
BNE NIE04
LDX #<CYF4
LDY #>CYF4
JMP POS0A
NIE04: CMP #$05
BNE NIE05
LDX #<CYF5
LDY #>CYF5
JMP POS0A
NIE05: CMP #$06
BNE NIE06
LDX #<CYF6
LDY #>CYF6
JMP POS0A
NIE06: CMP #$07
BNE NIE07
LDX #<CYF7
LDY #>CYF7
JMP POS0A
NIE07: CMP #$08
BNE NIE08
LDX #<CYF8
LDY #>CYF8
JMP POS0A
NIE08: LDX #<CYF9
LDY #>CYF9
JMP POS0A
POS1: INC KOPIUJ+1
LDA KOPIUJ+1
CMP #$00
BNE POS1A
INC KOPIUJ+3
POS1A: INC LICZPOZ
LDA LICZPOZ
CMP #1
BNE POS1B
LDX #<(BLOK13+1)
LDY #>(BLOK13+1)
POS1A1: STX POS0B+1
STY POS0C+1
JMP KOPIUJ
POS1B: CMP #2
BNE POS1C
LDX #<BLOK14
LDY #>BLOK14
JMP POS1A1
POS1C: CMP #3
BNE POS1D
LDX #<(BLOK14+1)
LDY #>(BLOK14+1)
JMP POS1A1
POS1D: CMP #4
BNE POS1E
LDX #<BLOK15
LDY #>BLOK15
JMP POS1A1
POS1E: CMP #5
BNE POS1F
LDX #<(BLOK15+1)
LDY #>(BLOK15+1)
JMP POS1A1
POS1F: JMP $EA31
START: LDX #$00
LDA #$00
STLOOP: STA BLOK13,X
STA BLOK14,X
STA BLOK15,X
INX
CPX #63
BEQ ST1
JMP STLOOP
ST1: LDX #$00
LDY #$00
ST1LOOP: LDA DWUKR,X
STA BLOK13+2,Y
STA BLOK14+2,Y
INX
CPX #8
BEQ ST2
INY
INY
INY
JMP ST1LOOP
ST2: LDX #13
STX WSKSP0
INX
STX WSKSP1
INX
STX WSKSP2
KOLOR: LDA #13
STA VIC+39
STA VIC+40
STA VIC+41
LDA #000110
STA VIC+16
LDA #215
LDX #50
STA VIC
STX VIC+1
LDA #7
STA VIC+2
STX VIC+3
ADC #48
STA VIC+4
STX VIC+5
LDA #000111
STA VIC+23
STA VIC+29
STA VIC+27
STA VIC+21
LDX #<MAIN
LDY #>MAIN
SEI
STX IRQWKT
STY IRQWKT+1
CLI
RTS
STEROW: JSR POBZNA
BEQ WYLACZ
JSR PRZECT
JSR ANAWYR
ROL 13
BCS NASTAW
ILLQUA: JMP 47000
NASTAW: JSR POBTXT
CMP #6
BNE ILLQUA
LDY #5
SEI
NASTPE: LDA (34),Y
SEC
SBC #48
STA CZAS,Y
DEY
BPL NASTPE
LDA #60
STA LICZNIK
CLI
JMP START
WYLACZ: LDX #$31
LDY #$EA
SEI
STX IRQWKT
STY IRQWKT+1
CLI
LDA #$00
STA VIC+21
RTS
In the next episode I will present a BASIC program that uses above clock to sound an alarm (sound and visual effects) at predefined time.
Thanks for reading.
Marek Karcz
2/3/2013
