;
; ********************************************
; * LED-grave 8-by-8 LED matrix              *
; * Version 1 as of January 2011             *
; * (C)2011 by http://avr-asm-tutorial.net   *
; ********************************************
;
; Include-file for ATmega16
.NOLIST
.INCLUDE "m16def.inc" ; Header for mega16
.LIST
;
; ============================================
;  H A R D W A R E   I N F O R M A T I O N S 
; ============================================
; ATmega16   ___________
;         1 /           |40
; S1-P0 o--|PB0      PA0|--o Col1u
; S2-P1 o--|PB1      PA1|--o Col2u
; S3-uu o--|PB2      PA2|--o Col3u
; S4-XR o--|PB3      PA3|--o Col4u
;        --|PB4      PA4|--o Col5u
;  MOSI o--|MOSI     PA5|--o Col6u
;  MISO o--|MISO     PA6|--o Col7u
;   SCK o--|SCK      PA7|--o Col8u
; RESET o--|RESET   AREF|--
;   VCC o--|VCC         |--o GND
;   GND o--|GND     AVCC|--
;        --|XTAL2    PC7|--o Col8l
;        --|XTAL1    PC6|--o Col7l
; Row1u o--|PD0      PC5|--o Col6l
; Row2u o--|PD1      PC4|--o Col5l
; Row3u o--|PD2      PC3|--o Col4l
; Row4u o--|PD3      PC2|--o Col3l
; Row1l o--|PD4      PC1|--o Col2l
; Row2l o--|PD5      PC0|--o Col1l
; Row3l o--|PD6      PD7|--o Row4l
;          |____________|
;
; Switches:
; ---------
;   S1,S2 : selects text sequences 0..3
;   S3 on : exchanges characters
;      off: rotates characters to the left 
;   S4 on : maximum display brightness
;      off: half display brightness
;
; Fuses:
; ------
;   The following fuses must be selected:
;   - JTAGEN fuse off (JTAG disabled)
;   - EESAVE fuse on (save EEPROM content
;     during flashing)
;   The following clock fuses have to be
;   selected (default value):
;   - SUT CK SEL = Int RC Osc, 1 MHz, 6 CK + 64 ms
;   Fuse setting: High=D1, Low=E1
;
; ============================================
;      P O R T S   A N D   P I N S 
; ============================================
;
.equ pColU = PORTA ; Upper Column driver
.equ pColUD = DDRA ; Upper Column direction
.equ pColL = PORTC ; Lower Column driver
.equ pColLD = DDRC ; Lower Column direction
.equ pRow  = PORTD ; Row driver
.equ pRowD = DDRD  ; Row driver direction
.equ pSw = PORTB ; Switch input port
.equ pSwD = DDRB ; Switch input port direction
;
;
; ============================================
;        P R O G R A M   I N F O 
; ============================================
;
; Processor clock:
;   The processor runs with its default setting:
;   internal RC clock generator with 1 MHz
;
; Timer 1:
;   16-bit-timer 1 is in CTC mode, using the ICR
;   register for timer compare and clear. Inter-
;   rupts are enabled on the ICR compare, muxing
;   the display column.
;   If display brightness has been selected low,
;   the Compare Match Int on compare register A
;   is additionally enabled. This Int switches
;   the row drivers off at half of the CTC time.
;
; LED driving:
;   Ports A and C drive the column transistors,
;   port D drives the row transistors.
;   Timer 1 int on ICR match
;   - clears all row drivers,
;   - outputs the column info in SRAM on ports A and C,
;   - switches the row driver on again.
;   The row byte (0x88, 0x44, 0x22,0x11) is then
;   shifted right. If a carry shift out, four shifts
;   have been made. The the row byte is restartet
;   at 0x88 and the pointer X to the mux data in
;   SRAM is restarted.
;   If four shifts have been made a counter is
;   decreased. If the counter reaches zero, the T flag
;   is set and the counter is reloaded from register
;   rAct. The T flag is cleared by the software outside
;   the Int.
;   Register rAct allows to dynamically select different
;   display speeds.
;   If S3 is off (shift in and out), the speed info
;   in the text stream is divided by eight to allow a
;   faster shifting.
;   If S4 is off, the LEDs are switched off after half
;   of the mux time (lower brightness). If S4 is on,
;   the LEDs are on over the complete mux time.
;
; Text display:
;   Four text sequences can be placed into the EEPROM,
;   each ending with a 0xFF character. Character code
;   is 7-bit-ASCII, the lower 32 characters are graphic
;   characters.
;   Within the text stream speed information can be
;   placed using codes between 128 and 254, setting
;   the speed (128=256 mux cycles, 129=1 mux cycle,
;   130=2 mux cycles, etc.).
;   Depending from the switches S1 and S2 one of the
;   four text sequences in the EEPROM is selected and
;   displayed.
;   If S3 is on, the text is displayed character by
;   character. If S3 is off the display shifts left and
;   the next character is shifted in from the right side.
;   
; ================================================
;     C O N S T A N T S   T O   C H A N G E
; ================================================
;
.equ mux_freq = 50 ; MUX frequency of the display
;
; =======================================================
;  F I X E D   A N D   D E R I V E D   C O N S T A N T S
; =======================================================
;
.equ clock = 1000000 ; Internal default RC clock frequency
.equ mux_int_freq = 4 * mux_freq ; interrupt frequency for MUX
.equ presc = 8 ; 16-bit timer prescaler
.equ comp = clock / presc / mux_int_freq ; 16-bit timer compare
;
; ============================================
;   R E G I S T E R   D E F I N I T I O N S
; ============================================
;
; used: R0 for LPM and other purposes outside ints, unnamed
; used: R1..R8 for shifting purposes outside ints, unnamed
; free: R9..R14
.def rSreg = R15 ; temporary SREG flag register
.def rmp = R16 ; multi purpose register outside ints
.def rimp = R17 ; multi purpose register inside ints
.def rCntDwn = R18 ; count down register
.def rMux = R19 ; mux row driver register
.def rAct = R20 ; number of mux cycles for T setting
.def rChr = R21 ; counter for rotating characters
.def rLCol = R22 ; column or register for last column  
; free: R23..R25
; used: R27:R26 (X) as pointer to mux data, inside ints
; used: R29:R28 (Y) for pointing purposes outside ints
; used: R31:R30 (Z) for pointing purposes outside ints 
;
; ============================================
;       S R A M   D E F I N I T I O N S
; ============================================
;
.DSEG
.ORG Sram_Start
MuxData: ; Display info for MUXing LEDs
.byte 8
;
; ==============================================
;   R E S E T   A N D   I N T   V E K T O R S
; ==============================================
;
.CSEG
.ORG $0000
	rjmp Main ; Reset-Vektor
	nop
	reti ; Int0
	nop
	reti ; Int1
	nop
	reti ; TC2 compare int
	nop
	reti ; TC2 overflow
	nop
	rjmp Tc1Capt ; TC1 capture int
	nop
	rjmp Tc1CmpA ; TC1 compare A
	nop
	reti ; TC1 compare B
	nop
	reti ; TC1 overflow
	nop
	reti ; TC0 overflow
	nop
	reti ; SPI STC
	nop
	reti ; USART RXC
	nop
	reti ; USART UDRE
	nop
	reti ; USART TXC
	nop
	reti ; ADC
	nop
	reti ; EE_RDY
	nop
	reti ; ANA_COMP
	nop
	reti ; TWI
	nop
	reti ; INT2
	nop
	reti ; TC0 Compare
	nop
	reti ; SPM Ready
	nop
;
;
; ==========================================
;    I N T E R R U P T   S E R V I C E S
; ==========================================
;
; MUX interrupt service routine
Tc1Capt:
	in rSreg,SREG
	ldi rimp,0 ; clear display
	out pRow,rimp
	ld rimp,X+ ; read upper column value
	out pColU,rimp ; write upper column driver
	ld rimp,X+ ; read lower column value
	out pColL,rimp ; write lower column driver
	out pRow,rMux ; activate display
	lsr rMux ; shift mux register right
	brcc Tc1Capt1 ; no carry, continue
	ldi rMux,0x88 ; start with first column
	ldi XL,LOW(MuxData) ; set pointer to first
	dec rCntDwn ; count down
	brne Tc1Capt1 ; not zero, go on
	mov rCntDwn,rAct ; restart counter
	out SREG,rSreg ; restore SREG
	set ; set T flag
	reti
Tc1Capt1:
	out SREG,rSreg ; restore SREG
	reti
;
; Tc1CmpA switches the display off
Tc1CmpA:
	ldi rimp,0 ; write 0 to row drivers
	out pRow,rimp
	reti
;
; ============================================
;    M A I N   P R O G R A M   I N I T
; ============================================
;
Main:
	; Init stack
	ldi rmp,HIGH(RAMEND) ; stack pointer to RAMEND
	out SPH,rmp
	ldi rmp,LOW(RAMEND)
	out SPL,rmp
	; Init Mux variables
	ldi rMux,0x88 ; start with highest rows, shift right
	ldi rAct,50 ; mux cycles for T-setting, 1 second
	mov rCntDwn,rAct ; mux cycle counter in ints
	ldi XH,HIGH(MuxData) ; point X to MuxData in SRAM
	ldi XL,LOW(MuxData)
	; Init display ports
	clr rmp ; all display ports off
	out pColU,rmp ; upper columns
	out pColL,rmp ; lower columns
	out pRow,rmp ; rows
	ldi rmp,0xFF ; all port drivers of display to output
	out pColUD,rmp ; upper column driver
	out pColLD,rmp ; lower column driver
	out pRowD,rmp ; row driver
	; Init display test
	ldi YH,HIGH(MuxData) ; point Y to mux in SRAM
	ldi YL,LOW(MuxData)
	ldi rmp,'A' ; Display character A on startup 
	rcall Rmp2Asc
	ldi rmp,8
WriteDisp:
	lpm R0,Z+
	st Y+,R0
	dec rmp
	brne WriteDisp
	; Init Switch ports
	clr rmp ; switch port direction to input
	out pSwD,rmp
	ldi rmp,0x0F ; pull-up resistor of switches to on
	out pSw,rmp
	; Init TC1 as mux timer with ICR-CTC and Compare A int
	ldi ZH,HIGH(comp) ; TC1 CTC value to ICR
	ldi ZL,LOW(comp)
	out ICR1H,ZH
	out ICR1L,ZL
	lsr ZH ; TC1 compare A to half time
	ror ZL
	out OCR1AH,ZH ; TC1 compare A value
	out OCR1AL,ZL
	ldi rmp,0 ; WGM11 and WGM10 to zero
	out TCCR1A,rmp
	ldi rmp,(1<<WGM13)|(1<<WGM12)|(1<<CS11) ; ICR-CTC, prescale 8
	out TCCR1B,rmp
	ldi rmp,(1<<TICIE1)|(1<<OCIE1A) ; enable both ints
	sbis PINB,3 ; switch input 3 off?
	ldi rmp,1<<TICIE1 ; enable CTC int only
	out TIMSK,rmp ; set timer int mask 
	ldi rmp,1<<SE ; Enable sleep
	out MCUCR,rmp
	sei
;
; ============================================
;         P R O G R A M - L O O P
; ============================================
;
Loop:
	sleep ; sleep until interrupt occurs
	nop ; Dummy for wake-up
	brtc Loop ; T flag clear?
	rcall TFlag ; call T flag routine
	rjmp loop ; back to Loop
;
; T flag has been set during interrupt
;
TFlag:
	clt ; clear T flag
	ldi rmp,(1<<TICIE1)|(1<<OCIE1A) ; enable both ints
	sbis PINB,3 ; switch input 3 off?
	ldi rmp,1<<TICIE1 ; enable CTC int only
	out TIMSK,rmp ; set timer int mask
	in rmp,PINB ; read switches
	andi rmp,0x03 ; mask the two lower switches
	ldi YH,HIGH(Text0) ; Point Y to EEPROM start
	ldi YL,LOW(Text0)
	mov R0,rmp
GetEep:
	breq Display ; Eeprom text found
	rcall ReadEep ; read next char
	brne GetEep ; wait for last char
	dec R0
	brne GetEep ; search for next text start
Display:
	brtc Display ; wait for T flag set
	clt ; clear T flag
	rcall ReadEep ; read character
	brne DisplayChkSpd ; not last character?
	rjmp DispEnd ; last char, end sequence
DisplayChkSpd:
	sbrs rmp,7 ; character?
	rjmp DisplayChar
	; set speed
	andi rmp,0x7F ; speed setting, clear bit 7
	sbis PINB,2 ; 1/8 speed if rotate is on
	rjmp DisplaySetSpeed
	lsr rmp ; / 2
	lsr rmp ; / 4
	lsr rmp ; / 8
	inc rmp ; + one to avoid 0
DisplaySetSpeed:
	mov rAct,rmp ; set speed register
	rjmp Display
DisplayChar:
	push YH ; save Y
	push YL
	rcall Rmp2Asc ; point Z to character in Ascii table
	sbic PINB,PINB2 ; exchange or rotate in
	rjmp DispRot
	; Exchange character direct, no shift-in
	ldi YH,HIGH(MuxData) ; point Y to Mux
	ldi YL,LOW(MuxData)
	ldi rmp,8 ; read the 8 bytes from table to mux data
DispExch:
	lpm R0,Z+ ; read ascii table info
	st Y+,R0 ; copy to SRAM
	dec rmp
	brne DispExch
	pop YL ; restore Y
	pop YH
	rjmp Display ; next character
	; shift the character from the left into the display 
DispRot:
	; read the character mux code to registers R1..R8
	ldi YH,0 ; point to register R1
	ldi YL,1
	ldi rmp,8
DispRotRdAsc:
	lpm R0,Z+ ; read char data to register R0
	st Y+,R0 ; copy char to registers R1..R8
	dec rmp
	brne DispRotRdAsc
	lsr rLCol ; last column of previous char empty?
	brcc DispRotGetCol
	; Shift an empty column into mux data
	ldi YH,HIGH(MuxData) ; Point Y to Mux
	ldi YL,LOW(MuxData)
	ldi rmp,8
DispRotEmptyCol:
	ld R0,Y ; read mux byte
	lsl R0 ; shift left with empty column
	st Y+,R0 ; store mux byte
	dec rmp
	brne DispRotEmptyCol
	; calc last column of new char
DispRotGetCol:
	clr rLCol
	or rLCol,R1
	or rLCol,R2
	or rLCol,R3
	or rLCol,R4
	or rLCol,R5
	or rLCol,R6
	or rLCol,R7
	or rLCol,R8
	set ; jump over next pause
	; shift the next char in
	ldi rChr,8 ; eight shifts
DispRotChar:
	brtc DispRotChar
	clt 
	ldi YH,0 ; point Y to register 1
	ldi YL,1
	ldi ZH,HIGH(MuxData) ; Point Z to Mux
	ldi ZL,LOW(MuxData)
	ldi rmp,8
DispRotate:
	ld R0,Y ; read register byte to R0
	lsl R0 ; shift highest byte to carry
	st Y+,R0 ; save register byte for next round
	ld R0,Z ; read mux byte
	rol R0 ; rotate carry into mux byte
	st Z+,R0 ; store mux data
	dec rmp ; count down
	brne DispRotate ; go on
	dec rChr
	brne DispRotChar
	pop YL ; restore Y
	pop YH
	rjmp Display ; go on displaying
	; sequence end, wait for a certain period
DispEnd:
	ldi YL,2 ; wait for two chars
	sbic PINB,2 ; rotate?
	rjmp DispEndRot
	ldi ZH,HIGH(MuxData) ; point Z to mux data
	ldi ZL,LOW(MuxData)
	clr R0
	ldi rmp,8
DispEndExch:
	st Z+,R0
	dec rmp
	brne DispEndExch
DispEndExchWait:
	brtc DispEndExchWait
	clt
	dec YL
	brne DispEndExchWait
	ret
DispEndRot:
	brtc DispEndRot ; wait for T flag
	clt ; clear T flag
	ldi ZH,HIGH(MuxData) ; point Z to mux data
	ldi ZL,LOW(MuxData)
	ldi rmp,8
DispEndShift:
	ld R0,Z ; read byte from Mux
	lsl R0 ; shift 0 in
	st Z+,R0
	dec rmp
	brne DispEndShift
	dec YL
	brne DispEndRot
	ret
;
; Read a character from EEPROM at Y
;   returns zero flag, if last character is reached
;
ReadEep:
	out EEARH,YH ; adress to adress register
	out EEARL,YL
	sbi EECR,EERE ; read strobe
	adiw YL,1 ; increase pointer to next location
	in rmp,EEDR ; read character
	cpi rmp,0xFF ; end of text?
	ret
; ============================================
;   D I S P L A Y   M A N I P U L A T I O N
; ============================================
;
;
; Point Z to Ascii-Char in rmp
;
Rmp2Asc:
  ldi ZH,HIGH(2*Ascii) ; point Z to Ascii table in flash
  ldi ZL,LOW(2*Ascii)
  clr R0
  lsl rmp ; multiply character code by 2, skip bit 7
  lsl rmp ; by 4
  rol R0
  lsl rmp ; by 8
  rol R0
  add ZL,rmp ; add to address
  adc ZH,R0 ; add MSB with overflow
  ret
;
; ============================================
;         A S C I I   T A B L E
; ============================================
;
; Ascii-table (1U,1L,2U,2L,3U,3L,4U,4L)
;   designed with calc-table.ods
;
Ascii:
.db 0,24,0,0,0,0,24,0 ; 'a0'
.db 0,36,0,60,60,0,36,0 ; 'a1'
.db 0,66,126,66,66,126,66,0 ; 'a2'
.db 255,129,129,129,129,129,129,255 ; 'a3'
.db 0,24,0,36,36,0,24,0 ; 'a4'
.db 0,24,66,36,36,66,24,0 ; 'a5'
.db 129,24,66,36,36,66,24,129 ; 'a6'
.db 0,255,0,0,0,0,0,0 ; 'a7'
.db 0,12,0,3,192,0,48,0 ; 'a8'
.db 128,8,64,4,32,2,16,1 ; 'a9'
.db 32,8,32,8,16,4,16,4 ; 'aa'
.db 16,16,16,16,16,16,16,16 ; 'ab'
.db 4,16,4,16,8,32,8,32 ; 'ac'
.db 1,16,2,32,4,64,8,128 ; 'ad'
.db 0,48,0,192,3,0,12,0 ; 'ae'
.db 0,0,0,0,0,0,0,0 ; 'af'
.db 0,16,0,0,0,0,16,0 ; '10'
.db 0,28,0,0,0,0,16,0 ; '11'
.db 0,28,0,0,4,0,20,0 ; '12'
.db 0,28,12,0,4,0,20,0 ; '13'
.db 0,28,60,0,4,0,20,0 ; '14'
.db 0,28,124,0,68,0,20,0 ; '15'
.db 0,92,124,0,68,0,84,0 ; '16'
.db 0,92,124,64,68,64,84,0 ; '17'
.db 0,92,124,64,68,112,84,0 ; '18'
.db 0,92,124,64,68,124,84,0 ; '19'
.db 0,92,124,64,68,127,84,0 ; '1A'
.db 0,93,124,65,68,127,84,0 ; '1B'
.db 0,93,124,65,69,127,85,0 ; '1C'
.db 0,93,125,65,69,127,85,0 ; '1D'
.db 0,0,0,0,0,0,0,0 ; '1E'
.db 0,0,0,0,0,0,0,0 ; '1F'
.db 0,0,0,0,0,0,0,0 ; ' '
.db 8,8,8,0,8,8,8,8 ; '!'
.db 36,0,36,0,0,0,0,0 ; '„'
.db 10,36,10,254,127,72,20,80 ; '#'
.db 8,40,8,42,28,28,42,8 ; 'c|'
.db 225,48,163,103,230,197,12,135 ; '%'
.db 24,113,36,78,68,38,120,25 ; '&'
.db 24,0,24,0,24,0,0,0 ; '''
.db 8,32,16,32,32,16,32,8 ; '('
.db 16,4,8,4,4,8,4,16 ; ')'
.db 0,126,90,60,60,90,126,0 ; '*'
.db 0,126,24,24,24,24,126,0 ; '+'
.db 0,0,0,8,0,24,0,48 ; ','
.db 0,60,0,0,0,0,60,0 ; '-'
.db 0,0,0,0,0,24,0,24 ; '.'
.db 6,24,6,24,12,48,12,48 ; '/'
.db 60,195,126,195,195,126,195,60 ; '0'
.db 6,6,30,6,62,6,102,6 ; '1'
.db 126,56,255,97,134,255,28,254 ; '2'
.db 56,30,124,135,135,124,30,56 ; '3'
.db 28,255,60,255,108,12,204,12 ; '4'
.db 255,102,255,3,192,198,254,252 ; '5'
.db 28,222,62,227,96,118,192,60 ; '6'
.db 255,24,3,48,6,96,12,192 ; '7'
.db 60,126,126,195,195,126,126,60 ; '8'
.db 60,63,126,3,195,190,231,254 ; ' 9'
.db 0,24,0,0,0,24,24,24 ; ':'
.db 0,12,0,0,0,12,12,24 ; ';'
.db 4,48,12,24,24,12,48,4 ; '<'
.db 0,0,0,60,0,0,60,0 ; ' ='
.db 32,12,48,24,24,48,12,32 ; '>'
.db 24,12,60,24,102,0,4,24 ; '?'
.db 124,168,130,185,132,130,184,124 ; '@'
.db 24,195,60,255,102,255,195,195 ; 'A'
.db 252,254,254,195,195,254,254,252 ; 'B'
.db 60,192,126,195,195,126,192,60 ; 'C'
.db 252,195,254,195,195,254,195,252 ; 'D'
.db 255,248,255,192,192,255,248,255 ; 'E'
.db 255,248,254,240,192,192,192,192 ; 'F'
.db 60,255,126,227,195,126,192,60 ; 'G'
.db 195,255,195,195,195,195,255,195 ; 'H'
.db 60,24,24,24,24,24,24,60 ; 'I'
.db 255,3,255,198,3,252,3,120 ; 'J'
.db 198,240,204,216,216,204,240,198 ; 'K'
.db 192,192,192,192,192,254,192,254 ; 'L'
.db 195,219,231,195,255,195,219,195 ; 'M'
.db 195,219,227,207,243,199,219,195 ; 'N'
.db 24,195,60,102,102,60,195,24 ; 'O'
.db 252,252,254,192,195,192,254,192 ; 'P'
.db 24,203,60,102,102,62,195,27 ; 'Q'
.db 252,254,254,204,195,198,254,195 ; 'R'
.db 60,126,126,3,195,254,224,124 ; 'S'
.db 255,24,255,24,24,24,24,24 ; 'T'
.db 195,195,195,195,195,126,195,60 ; 'U'
.db 195,195,195,102,195,60,195,24 ; 'V'
.db 195,219,195,219,195,231,219,102 ; 'W'
.db 195,60,195,102,102,195,60,195 ; 'X'
.db 195,60,195,24,195,24,102,24 ; 'Y'
.db 255,24,255,49,134,127,12,254 ; 'Z'
.db 56,32,32,32,32,32,32,56 ; '['
.db 48,4,16,4,8,2,8,2 ; '\'
.db 28,4,4,4,4,4,4,28 ; ']'
.db 8,0,20,0,34,0,0,0 ; '^'
.db 0,0,0,0,0,0,0,255 ; '_'
.db 6,0,12,0,24,0,0,0 ; '´'
.db 0,38,0,98,0,38,26,26 ; ' a'
.db 32,50,32,35,32,50,44,44 ; ' b'
.db 0,102,0,64,0,102,60,60 ; ' c'
.db 4,124,4,132,4,124,52,52 ; ' d'
.db 0,50,0,100,0,41,30,30 ; ' e'
.db 14,30,26,16,16,16,16,16 ; ' f'
.db 0,68,0,60,0,4,56,120 ; ' g'
.db 32,56,32,36,32,36,32,36 ; ' h'
.db 0,16,0,16,16,16,0,16 ; ' i'
.db 0,8,8,8,0,40,8,16 ; ' j'
.db 32,40,32,48,32,40,38,38 ; ' k'
.db 32,32,32,32,32,18,32,12 ; ' l'
.db 0,180,0,218,0,146,0,146 ; ' m'
.db 0,44,0,50,0,34,0,34 ; ' n'
.db 0,24,0,36,0,36,0,24 ; ' o'
.db 0,26,0,26,0,20,20,16 ; ' p'
.db 0,76,0,76,0,52,52,4 ; ' q'
.db 0,50,0,32,0,32,44,32 ; ' r'
.db 0,48,0,8,24,36,36,24 ; ' s'
.db 32,32,32,32,32,18,120,12 ; ' t'
.db 0,34,0,34,0,38,34,26 ; ' u'
.db 0,34,0,20,0,20,34,8 ; ' v'
.db 0,129,0,90,0,90,129,36 ; ' w'
.db 0,40,0,16,0,40,68,68 ; ' x'
.db 0,36,0,28,0,4,36,4 ; ' y'
.db 0,8,0,16,0,36,124,124 ; ' z'
.db 12,48,8,8,8,8,48,12 ; '0'
.db 8,8,8,8,8,8,8,8 ; '|'
.db 24,6,8,8,8,8,6,24 ; '}'
.db 0,74,0,132,0,0,49,0 ; '~'
;
; ============================================
;    D I S P L A Y   T E X T   E E P R O M     
; ============================================
;
.eseg ; Start of EEPROM segment
;  bytes 128..254: set speed to (value-128),
;     if rotate-in is selected: (value-128) / 8
;  byte 0xFF to stop and restart sequence
.org $0000
;
Text0:
.db 4+0x80,' ',0,1,2,3,2,1,0 ; explode and implode
.db 16+0x80,4,5,6,5,4,0,' ' ; cross
.db 4+0x80,7,8,9,10,11,12,13,14,7,' ' ; rotate 
.db 16+0x80,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30 ; spiral
.db 32+0x80,29,28,27,26,25,24,23,22,21,20,19,18,17,16,' ' ; spiral back
.db 0xFF
Text1:
.db 32+0x80,"Gerhard Schmidt, Kastanienallee 20, 64289 Darmstadt",0xFF
Text2:
.db 40+0x80,"Welcome to LED grave by DG4FAC, version 1 ",0xFF
Text3:
.db 64+0x80,"Text unprogrammed ",0xFF
;
; End of EEPROM segment
.cseg
;
; End of source code
; Copyright info
.db "(C)2010 by Gerhard Schmidt  " ; menschenlesbar
.db "C(2)10 0ybG reahdrS hcimtd  " ; wortgerecht
;