1 files changed, 132 insertions, 0 deletions
diff --git a/roms/lcd_no_ram.asm b/roms/lcd_no_ram.asm
new file mode 100644
index 0000000..7616dcf
--- /dev/null
+++ b/roms/lcd_no_ram.asm
@@ -0,0 +1,132 @@
+PORTB = $6000
+PORTA = $6001
+DDRB  = $6002
+DDRA  = $6003
+
+E     = %10000000
+RW    = %01000000
+RS    = %00100000
+
+ .org #$f800
+
+reset:
+ lda #%11111111			; set output on all pins of PORTB
+ sta DDRB
+
+ lda #%11100000			; set output on LCD control pins of PORTA
+ sta DDRA
+
+ lda #%00111000			; set 8-bit, 2-line display, 5x8 font
+ sta PORTB
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #E				; clear RS/RW, set E, send instruction
+ sta PORTA
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #%00001110			; display on, cursor on, no blink
+ sta PORTB
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #E				; clear RS/RW, set E, send instruction
+ sta PORTA
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #%00000001			; clear display
+ sta PORTB
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #E				; clear RS/RW, set E, send instruction
+ sta PORTA
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #%00000010			; return home
+ sta PORTB
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #E				; clear RS/RW, set E, send instruction
+ sta PORTA
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #%00000110			; set entry mode: increment, no shift
+ sta PORTB
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #E				; clear RS/RW, set E, send instruction
+ sta PORTA
+
+ lda #$0			; clear RS/RW/E
+ sta PORTA
+
+ lda #'6'			; data to send
+ sta PORTB
+
+ lda #RS			; clear RW, E, set RS for data
+ sta PORTA
+
+ lda #( E | RS )		; clear RW, set E/RS, send data
+ sta PORTA
+
+ lda #RS			; clear RS, E, keep RS
+ sta PORTA
+
+ lda #'5'			; data to send
+ sta PORTB
+
+ lda #RS			; clear RW, E, set RS for data
+ sta PORTA
+
+ lda #( E | RS )		; clear RW, set E/RS, send data
+ sta PORTA
+
+ lda #RS			; clear RS, E, keep RS
+ sta PORTA
+
+ lda #'0'			; data to send
+ sta PORTB
+
+ lda #RS			; clear RW, E, set RS for data
+ sta PORTA
+
+ lda #( E | RS )		; clear RW, set E/RS, send data
+ sta PORTA
+
+ lda #RS			; clear RS, E, keep RS
+ sta PORTA
+
+ lda #'2'			; data to send
+ sta PORTB
+
+ lda #RS			; clear RW, E, set RS for data
+ sta PORTA
+
+ lda #( E | RS )		; clear RW, set E/RS, send data
+ sta PORTA
+
+ lda #RS			; clear RS, E, keep RS
+ sta PORTA
+
+end:
+ jmp end
+
+ .org #$fffc
+ .word reset
+ .word $0000