Game 1 Unit 5 of 64 1 hr learning time

Custom Tiles

Design better tile graphics for the arena.

8% of Neon Nexus

Mark as complete Completed!

What You’re Building

Custom-designed tiles that make the arena look polished.

Custom Tiles

The border has a brick pattern. The corners have diagonal edges. The floor has a subtle grid.

How NES Tiles Work

Each tile is 8×8 pixels with 4 possible colours. The pattern table stores tiles as two bit-planes:

Low plane: 8 bytes, one per row
High plane: 8 bytes, one per row
Combine bits from both planes: 0-3 selects palette colour

Low bit:  1  High bit: 0  →  Colour 1
Low bit:  0  High bit: 1  →  Colour 2
Low bit:  1  High bit: 1  →  Colour 3
Low bit:  0  High bit: 0  →  Colour 0 (transparent/background)

Designing the Border Tile

A brick pattern alternates between solid rows and rows with gaps:

; Tile 1: Border (brick pattern)
.byte %11111111   ; Row 0: solid
.byte %10000001   ; Row 1: edges only
.byte %10000001   ; Row 2: edges only
.byte %11111111   ; Row 3: solid
.byte %11111111   ; Row 4: solid
.byte %00010001   ; Row 5: offset gaps
.byte %00010001   ; Row 6: offset gaps
.byte %11111111   ; Row 7: solid

The high plane adds colour variation within the tile.

Corner Tiles

Diagonal corners make the arena look less blocky:

; Tile 3: Corner TL (diagonal from top-left)
.byte %11111111   ; Row 0
.byte %11000000   ; Row 1
.byte %10100000   ; Row 2
.byte %10010000   ; Row 3
.byte %10001000   ; Row 4
.byte %10000100   ; Row 5
.byte %10000010   ; Row 6
.byte %10000001   ; Row 7

Four corner tiles (TL, TR, BL, BR) are mirrored versions of each other.

The Floor Tile

A subtle grid pattern adds visual texture without being distracting:

; Tile 2: Floor (subtle grid)
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %10000001   ; Small dots at corners

Drawing Corners

The arena drawing code now places corner tiles at the four corners:

@top_row:
    lda row_counter
    cmp #0
    bne @top_row_inner

    ; Very top row with corners
    lda #TILE_CORNER_TL
    sta PPUDATA
    lda #TILE_BORDER
    ldx #30
@top_fill:
    sta PPUDATA
    dex
    bne @top_fill
    lda #TILE_CORNER_TR
    sta PPUDATA
    jmp @next_row

The Code

; =============================================================================
; NEON NEXUS - Unit 5: Custom Tiles
; =============================================================================
; Design better tile graphics for the arena.
; =============================================================================

; -----------------------------------------------------------------------------
; NES Hardware Addresses
; -----------------------------------------------------------------------------
PPUCTRL   = $2000
PPUMASK   = $2001
PPUSTATUS = $2002
OAMADDR   = $2003
PPUSCROLL = $2005
PPUADDR   = $2006
PPUDATA   = $2007
OAMDMA    = $4014

JOYPAD1   = $4016
JOYPAD2   = $4017

; Controller buttons
BTN_A      = %10000000
BTN_B      = %01000000
BTN_SELECT = %00100000
BTN_START  = %00010000
BTN_UP     = %00001000
BTN_DOWN   = %00000100
BTN_LEFT   = %00000010
BTN_RIGHT  = %00000001

; -----------------------------------------------------------------------------
; Game Constants
; -----------------------------------------------------------------------------
PLAYER_START_X = 124
PLAYER_START_Y = 116
PLAYER_SPEED   = 2

; Tile indices (background)
TILE_EMPTY     = 0
TILE_BORDER    = 1
TILE_FLOOR     = 2
TILE_CORNER_TL = 3   ; Top-left corner
TILE_CORNER_TR = 4   ; Top-right corner
TILE_CORNER_BL = 5   ; Bottom-left corner
TILE_CORNER_BR = 6   ; Bottom-right corner

; Sprite tiles (after background tiles in pattern table 0)
SPRITE_PLAYER  = 7

; Arena boundaries
ARENA_LEFT   = 16
ARENA_RIGHT  = 232
ARENA_TOP    = 16
ARENA_BOTTOM = 208

BG_COLOUR = $0F

; -----------------------------------------------------------------------------
; Memory Layout
; -----------------------------------------------------------------------------
.segment "ZEROPAGE"
player_x:    .res 1
player_y:    .res 1
buttons:     .res 1
temp:        .res 1
row_counter: .res 1

.segment "OAM"
oam_buffer:  .res 256

.segment "BSS"

; -----------------------------------------------------------------------------
; iNES Header
; -----------------------------------------------------------------------------
.segment "HEADER"
    .byte "NES", $1A
    .byte 2
    .byte 1
    .byte $01
    .byte $00
    .byte 0,0,0,0,0,0,0,0

; -----------------------------------------------------------------------------
; Code
; -----------------------------------------------------------------------------
.segment "CODE"

reset:
    sei
    cld
    ldx #$40
    stx $4017
    ldx #$FF
    txs
    inx
    stx PPUCTRL
    stx PPUMASK
    stx $4010

@vblank1:
    bit PPUSTATUS
    bpl @vblank1

    lda #0
@clear_ram:
    sta $0000, x
    sta $0100, x
    sta $0200, x
    sta $0300, x
    sta $0400, x
    sta $0500, x
    sta $0600, x
    sta $0700, x
    inx
    bne @clear_ram

@vblank2:
    bit PPUSTATUS
    bpl @vblank2

    jsr load_palette
    jsr draw_arena

    ; Set up player
    lda #PLAYER_START_X
    sta player_x
    lda #PLAYER_START_Y
    sta player_y

    ; Initialise player sprite
    lda player_y
    sta oam_buffer+0
    lda #SPRITE_PLAYER
    sta oam_buffer+1
    lda #0
    sta oam_buffer+2
    lda player_x
    sta oam_buffer+3

    ; Hide other sprites
    lda #$FF
    ldx #4
@hide_sprites:
    sta oam_buffer, x
    inx
    bne @hide_sprites

    lda #0
    sta PPUSCROLL
    sta PPUSCROLL

    ; Enable rendering - both background and sprites from pattern table 0
    lda #%10000000
    sta PPUCTRL
    lda #%00011110
    sta PPUMASK

main_loop:
    jsr read_controller
    jsr move_player
    jmp main_loop

; -----------------------------------------------------------------------------
; Load Palette
; -----------------------------------------------------------------------------
load_palette:
    bit PPUSTATUS
    lda #$3F
    sta PPUADDR
    lda #$00
    sta PPUADDR

    ldx #0
@loop:
    lda palette_data, x
    sta PPUDATA
    inx
    cpx #32
    bne @loop
    rts

; -----------------------------------------------------------------------------
; Draw Arena (with corner tiles)
; -----------------------------------------------------------------------------
draw_arena:
    bit PPUSTATUS
    lda #$20
    sta PPUADDR
    lda #$00
    sta PPUADDR

    lda #0
    sta row_counter

@draw_row:
    lda row_counter

    ; Row 0: top border with corners
    cmp #0
    beq @top_row
    cmp #1
    beq @top_row

    ; Row 28-29: bottom border with corners
    cmp #28
    beq @bottom_row
    cmp #29
    beq @bottom_row

    ; Middle rows
    jmp @middle_row

@top_row:
    lda row_counter
    cmp #0
    bne @top_row_inner

    ; Very top row with corners
    lda #TILE_CORNER_TL
    sta PPUDATA
    lda #TILE_BORDER
    ldx #30
@top_fill:
    sta PPUDATA
    dex
    bne @top_fill
    lda #TILE_CORNER_TR
    sta PPUDATA
    jmp @next_row

@top_row_inner:
    ; Second row - all border
    lda #TILE_BORDER
    ldx #32
@top_inner_fill:
    sta PPUDATA
    dex
    bne @top_inner_fill
    jmp @next_row

@bottom_row:
    lda row_counter
    cmp #29
    bne @bottom_row_inner

    ; Very bottom row with corners
    lda #TILE_CORNER_BL
    sta PPUDATA
    lda #TILE_BORDER
    ldx #30
@bottom_fill:
    sta PPUDATA
    dex
    bne @bottom_fill
    lda #TILE_CORNER_BR
    sta PPUDATA
    jmp @next_row

@bottom_row_inner:
    ; Row 28 - all border
    lda #TILE_BORDER
    ldx #32
@bottom_inner_fill:
    sta PPUDATA
    dex
    bne @bottom_inner_fill
    jmp @next_row

@middle_row:
    ; Left border
    lda #TILE_BORDER
    sta PPUDATA
    sta PPUDATA

    ; Floor
    lda #TILE_FLOOR
    ldx #28
@floor_fill:
    sta PPUDATA
    dex
    bne @floor_fill

    ; Right border
    lda #TILE_BORDER
    sta PPUDATA
    sta PPUDATA

@next_row:
    inc row_counter
    lda row_counter
    cmp #30
    beq @done_drawing
    jmp @draw_row

@done_drawing:
    rts

; -----------------------------------------------------------------------------
; Read Controller
; -----------------------------------------------------------------------------
read_controller:
    lda #1
    sta JOYPAD1
    lda #0
    sta JOYPAD1

    ldx #8
@read_loop:
    lda JOYPAD1
    lsr a
    rol buttons
    dex
    bne @read_loop
    rts

; -----------------------------------------------------------------------------
; Move Player
; -----------------------------------------------------------------------------
move_player:
    lda buttons
    and #BTN_UP
    beq @check_down
    lda player_y
    sec
    sbc #PLAYER_SPEED
    cmp #ARENA_TOP
    bcc @check_down
    sta player_y

@check_down:
    lda buttons
    and #BTN_DOWN
    beq @check_left
    lda player_y
    clc
    adc #PLAYER_SPEED
    cmp #ARENA_BOTTOM
    bcs @check_left
    sta player_y

@check_left:
    lda buttons
    and #BTN_LEFT
    beq @check_right
    lda player_x
    sec
    sbc #PLAYER_SPEED
    cmp #ARENA_LEFT
    bcc @check_right
    sta player_x

@check_right:
    lda buttons
    and #BTN_RIGHT
    beq @done
    lda player_x
    clc
    adc #PLAYER_SPEED
    cmp #ARENA_RIGHT
    bcs @done
    sta player_x

@done:
    rts

; === NMI ===
nmi:
    pha
    txa
    pha
    tya
    pha

    lda #0
    sta OAMADDR
    lda #>oam_buffer
    sta OAMDMA

    lda player_y
    sta oam_buffer+0
    lda player_x
    sta oam_buffer+3

    lda #0
    sta PPUSCROLL
    sta PPUSCROLL

    pla
    tay
    pla
    tax
    pla
    rti

irq:
    rti

; -----------------------------------------------------------------------------
; Data
; -----------------------------------------------------------------------------
palette_data:
    ; Background palettes - neon theme
    .byte BG_COLOUR, $11, $21, $31  ; Blue gradient
    .byte BG_COLOUR, $11, $21, $31
    .byte BG_COLOUR, $11, $21, $31
    .byte BG_COLOUR, $11, $21, $31
    ; Sprite palettes
    .byte BG_COLOUR, $30, $27, $17  ; White, orange, brown
    .byte BG_COLOUR, $30, $27, $17
    .byte BG_COLOUR, $30, $27, $17
    .byte BG_COLOUR, $30, $27, $17

; -----------------------------------------------------------------------------
; Vectors
; -----------------------------------------------------------------------------
.segment "VECTORS"
    .word nmi
    .word reset
    .word irq

; -----------------------------------------------------------------------------
; CHR-ROM - Background Tiles (Pattern Table 0)
; -----------------------------------------------------------------------------
.segment "CHARS"

; Tile 0: Empty
.byte $00,$00,$00,$00,$00,$00,$00,$00
.byte $00,$00,$00,$00,$00,$00,$00,$00

; Tile 1: Border (brick pattern)
.byte %11111111   ; Row 0
.byte %10000001   ; Row 1
.byte %10000001   ; Row 2
.byte %11111111   ; Row 3
.byte %11111111   ; Row 4
.byte %00010001   ; Row 5
.byte %00010001   ; Row 6
.byte %11111111   ; Row 7
; High plane - add colour variation
.byte %00000000
.byte %01111110
.byte %01111110
.byte %00000000
.byte %00000000
.byte %11101110
.byte %11101110
.byte %00000000

; Tile 2: Floor (subtle grid)
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %10000001
; High plane
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000

; Tile 3: Corner TL
.byte %11111111
.byte %11000000
.byte %10100000
.byte %10010000
.byte %10001000
.byte %10000100
.byte %10000010
.byte %10000001
.byte %00000000
.byte %00111111
.byte %01011111
.byte %01101111
.byte %01110111
.byte %01111011
.byte %01111101
.byte %01111110

; Tile 4: Corner TR
.byte %11111111
.byte %00000011
.byte %00000101
.byte %00001001
.byte %00010001
.byte %00100001
.byte %01000001
.byte %10000001
.byte %00000000
.byte %11111100
.byte %11111010
.byte %11110110
.byte %11101110
.byte %11011110
.byte %10111110
.byte %01111110

; Tile 5: Corner BL
.byte %10000001
.byte %10000010
.byte %10000100
.byte %10001000
.byte %10010000
.byte %10100000
.byte %11000000
.byte %11111111
.byte %01111110
.byte %01111101
.byte %01111011
.byte %01110111
.byte %01101111
.byte %01011111
.byte %00111111
.byte %00000000

; Tile 6: Corner BR
.byte %10000001
.byte %01000001
.byte %00100001
.byte %00010001
.byte %00001001
.byte %00000101
.byte %00000011
.byte %11111111
.byte %01111110
.byte %10111110
.byte %11011110
.byte %11101110
.byte %11110110
.byte %11111010
.byte %11111100
.byte %00000000

; Sprite 0: Player (better ship design) - at tile index 0 in sprite table
; This goes immediately after background tiles
.byte %00011000   ; Row 0
.byte %00011000   ; Row 1
.byte %00111100   ; Row 2
.byte %01111110   ; Row 3
.byte %11111111   ; Row 4
.byte %10111101   ; Row 5
.byte %00100100   ; Row 6
.byte %00100100   ; Row 7
; High plane
.byte %00000000
.byte %00011000
.byte %00011000
.byte %00111100
.byte %01000010
.byte %01000010
.byte %00011000
.byte %00000000

; Fill rest of CHR-ROM (8KB total = 8192 bytes, used 128 so far)
.res 8192 - 128, $00

Build It

ca65 nexus.asm -o nexus.o
ld65 -C nes.cfg nexus.o -o nexus.nes

The arena now has character. Custom tiles transform a functional border into something that looks designed.

The tiles look good but use only one palette. Unit 6 adds colour regions with the attribute table.

What Changed

Unit 4 → Unit 5

+235-82

1	1		`; =============================================================================`
2		-	`; NEON NEXUS - Unit 4: The Background`
	2	+	`; NEON NEXUS - Unit 5: Custom Tiles`
3	3		`; =============================================================================`
4		-	`; Add a bordered arena using the nametable.`
	4	+	`; Design better tile graphics for the arena.`
5	5		`; =============================================================================`
6	6
7	7		`; -----------------------------------------------------------------------------`
			...
36	36		`PLAYER_START_Y = 116`
37	37		`PLAYER_SPEED = 2`
38	38
39		-	`; Tile indices`
40		-	`TILE_EMPTY = 0`
41		-	`TILE_BORDER = 1`
42		-	`TILE_FLOOR = 2`
43		-	`TILE_PLAYER = 3`
	39	+	`; Tile indices (background)`
	40	+	`TILE_EMPTY = 0`
	41	+	`TILE_BORDER = 1`
	42	+	`TILE_FLOOR = 2`
	43	+	`TILE_CORNER_TL = 3 ; Top-left corner`
	44	+	`TILE_CORNER_TR = 4 ; Top-right corner`
	45	+	`TILE_CORNER_BL = 5 ; Bottom-left corner`
	46	+	`TILE_CORNER_BR = 6 ; Bottom-right corner`
44	47
45		-	`; Arena boundaries (in pixels, accounting for border)`
46		-	`ARENA_LEFT = 16 ; 2 border tiles × 8`
47		-	`ARENA_RIGHT = 232 ; 256 - 16 - 8 (sprite width)`
	48	+	`; Sprite tiles (after background tiles in pattern table 0)`
	49	+	`SPRITE_PLAYER = 7`
	50	+
	51	+	`; Arena boundaries`
	52	+	`ARENA_LEFT = 16`
	53	+	`ARENA_RIGHT = 232`
48	54		`ARENA_TOP = 16`
49		-	`ARENA_BOTTOM = 208 ; 240 - 16 - 16 (overscan + border)`
	55	+	`ARENA_BOTTOM = 208`
50	56
51		-	`; Palette`
52		-	`BG_COLOUR = $0F ; Black background`
	57	+	`BG_COLOUR = $0F`
53	58
54	59		`; -----------------------------------------------------------------------------`
55	60		`; Memory Layout`
			...
59	64		`player_y: .res 1`
60	65		`buttons: .res 1`
61	66		`temp: .res 1`
	67	+	`row_counter: .res 1`
62	68
63	69		`.segment "OAM"`
64	70		`oam_buffer: .res 256`
			...
114	120		`bit PPUSTATUS`
115	121		`bpl @vblank2`
116	122
117		-	`; Load palette`
118	123		`jsr load_palette`
119		-
120		-	`; Draw the arena`
121	124		`jsr draw_arena`
122	125
123	126		`; Set up player`
			...
129	132		`; Initialise player sprite`
130	133		`lda player_y`
131	134		`sta oam_buffer+0`
132		-	`lda #TILE_PLAYER`
	135	+	`lda #SPRITE_PLAYER`
133	136		`sta oam_buffer+1`
134	137		`lda #0`
135	138		`sta oam_buffer+2`
			...
144	147		`inx`
145	148		`bne @hide_sprites`
146	149
147		-	`; Reset scroll`
148	150		`lda #0`
149	151		`sta PPUSCROLL`
150	152		`sta PPUSCROLL`
151	153
152		-	`; Enable rendering`
153		-	`lda #%10000000 ; NMI on, background and sprites from pattern table 0`
	154	+	`; Enable rendering - both background and sprites from pattern table 0`
	155	+	`lda #%10000000`
154	156		`sta PPUCTRL`
155		-	`lda #%00011110 ; Show sprites and background`
	157	+	`lda #%00011110`
156	158		`sta PPUMASK`
157	159
158		-	`; === Main Loop ===`
159	160		`main_loop:`
160	161		`jsr read_controller`
161	162		`jsr move_player`
			...
181	182		`rts`
182	183
183	184		`; -----------------------------------------------------------------------------`
184		-	`; Draw Arena`
	185	+	`; Draw Arena (with corner tiles)`
185	186		`; -----------------------------------------------------------------------------`
186	187		`draw_arena:`
187		-	`; Set PPU address to start of nametable ($2000)`
188	188		`bit PPUSTATUS`
189	189		`lda #$20`
190	190		`sta PPUADDR`
191	191		`lda #$00`
192	192		`sta PPUADDR`
193	193
194		-	`; Draw 30 rows`
195		-	`ldy #0 ; Row counter`
	194	+	`lda #0`
	195	+	`sta row_counter`
196	196
197	197		`@draw_row:`
198		-	`; Check if first row, last row, or middle`
199		-	`cpy #0`
200		-	`beq @border_row`
201		-	`cpy #1`
202		-	`beq @border_row`
203		-	`cpy #28`
204		-	`beq @border_row`
205		-	`cpy #29`
206		-	`beq @border_row`
	198	+	`lda row_counter`
207	199
208		-	`; Middle row: border + floor + border`
	200	+	`; Row 0: top border with corners`
	201	+	`cmp #0`
	202	+	`beq @top_row`
	203	+	`cmp #1`
	204	+	`beq @top_row`
	205	+
	206	+	`; Row 28-29: bottom border with corners`
	207	+	`cmp #28`
	208	+	`beq @bottom_row`
	209	+	`cmp #29`
	210	+	`beq @bottom_row`
	211	+
	212	+	`; Middle rows`
209	213		`jmp @middle_row`
210	214
211		-	`@border_row:`
212		-	`; All border tiles`
	215	+	`@top_row:`
	216	+	`lda row_counter`
	217	+	`cmp #0`
	218	+	`bne @top_row_inner`
	219	+
	220	+	`; Very top row with corners`
	221	+	`lda #TILE_CORNER_TL`
	222	+	`sta PPUDATA`
	223	+	`lda #TILE_BORDER`
	224	+	`ldx #30`
	225	+	`@top_fill:`
	226	+	`sta PPUDATA`
	227	+	`dex`
	228	+	`bne @top_fill`
	229	+	`lda #TILE_CORNER_TR`
	230	+	`sta PPUDATA`
	231	+	`jmp @next_row`
	232	+
	233	+	`@top_row_inner:`
	234	+	`; Second row - all border`
	235	+	`lda #TILE_BORDER`
213	236		`ldx #32`
214		-	`@border_loop:`
	237	+	`@top_inner_fill:`
	238	+	`sta PPUDATA`
	239	+	`dex`
	240	+	`bne @top_inner_fill`
	241	+	`jmp @next_row`
	242	+
	243	+	`@bottom_row:`
	244	+	`lda row_counter`
	245	+	`cmp #29`
	246	+	`bne @bottom_row_inner`
	247	+
	248	+	`; Very bottom row with corners`
	249	+	`lda #TILE_CORNER_BL`
	250	+	`sta PPUDATA`
215	251		`lda #TILE_BORDER`
	252	+	`ldx #30`
	253	+	`@bottom_fill:`
216	254		`sta PPUDATA`
217	255		`dex`
218		-	`bne @border_loop`
	256	+	`bne @bottom_fill`
	257	+	`lda #TILE_CORNER_BR`
	258	+	`sta PPUDATA`
	259	+	`jmp @next_row`
	260	+
	261	+	`@bottom_row_inner:`
	262	+	`; Row 28 - all border`
	263	+	`lda #TILE_BORDER`
	264	+	`ldx #32`
	265	+	`@bottom_inner_fill:`
	266	+	`sta PPUDATA`
	267	+	`dex`
	268	+	`bne @bottom_inner_fill`
219	269		`jmp @next_row`
220	270
221	271		`@middle_row:`
222		-	`; Left border (2 tiles)`
	272	+	`; Left border`
223	273		`lda #TILE_BORDER`
224	274		`sta PPUDATA`
225	275		`sta PPUDATA`
226	276
227		-	`; Floor (28 tiles)`
228		-	`ldx #28`
229		-	`@floor_loop:`
	277	+	`; Floor`
230	278		`lda #TILE_FLOOR`
	279	+	`ldx #28`
	280	+	`@floor_fill:`
231	281		`sta PPUDATA`
232	282		`dex`
233		-	`bne @floor_loop`
	283	+	`bne @floor_fill`
234	284
235		-	`; Right border (2 tiles)`
	285	+	`; Right border`
236	286		`lda #TILE_BORDER`
237	287		`sta PPUDATA`
238	288		`sta PPUDATA`
239	289
240	290		`@next_row:`
241		-	`iny`
242		-	`cpy #30`
243		-	`bne @draw_row`
	291	+	`inc row_counter`
	292	+	`lda row_counter`
	293	+	`cmp #30`
	294	+	`beq @done_drawing`
	295	+	`jmp @draw_row`
244	296
	297	+	`@done_drawing:`
245	298		`rts`
246	299
247	300		`; -----------------------------------------------------------------------------`
			...
266	319		`; Move Player`
267	320		`; -----------------------------------------------------------------------------`
268	321		`move_player:`
269		-	`; UP`
270	322		`lda buttons`
271	323		`and #BTN_UP`
272	324		`beq @check_down`
			...
321	373		`tya`
322	374		`pha`
323	375
324		-	`; DMA sprites`
325	376		`lda #0`
326	377		`sta OAMADDR`
327	378		`lda #>oam_buffer`
328	379		`sta OAMDMA`
329	380
330		-	`; Update sprite position`
331	381		`lda player_y`
332	382		`sta oam_buffer+0`
333	383		`lda player_x`
334	384		`sta oam_buffer+3`
335	385
336		-	`; Reset scroll (important after any PPU access)`
337	386		`lda #0`
338	387		`sta PPUSCROLL`
339	388		`sta PPUSCROLL`
			...
352	401		`; Data`
353	402		`; -----------------------------------------------------------------------------`
354	403		`palette_data:`
355		-	`; Background palettes`
356		-	`.byte BG_COLOUR, $12, $21, $30 ; Palette 0: black, blue, cyan (border), white`
357		-	`.byte BG_COLOUR, $12, $21, $30 ; Palette 1`
358		-	`.byte BG_COLOUR, $12, $21, $30 ; Palette 2`
359		-	`.byte BG_COLOUR, $12, $21, $30 ; Palette 3`
	404	+	`; Background palettes - neon theme`
	405	+	`.byte BG_COLOUR, $11, $21, $31 ; Blue gradient`
	406	+	`.byte BG_COLOUR, $11, $21, $31`
	407	+	`.byte BG_COLOUR, $11, $21, $31`
	408	+	`.byte BG_COLOUR, $11, $21, $31`
360	409		`; Sprite palettes`
361		-	`.byte BG_COLOUR, $30, $20, $16 ; Palette 0: black, white, red, orange`
362		-	`.byte BG_COLOUR, $30, $20, $16 ; Palette 1`
363		-	`.byte BG_COLOUR, $30, $20, $16 ; Palette 2`
364		-	`.byte BG_COLOUR, $30, $20, $16 ; Palette 3`
	410	+	`.byte BG_COLOUR, $30, $27, $17 ; White, orange, brown`
	411	+	`.byte BG_COLOUR, $30, $27, $17`
	412	+	`.byte BG_COLOUR, $30, $27, $17`
	413	+	`.byte BG_COLOUR, $30, $27, $17`
365	414
366	415		`; -----------------------------------------------------------------------------`
367	416		`; Vectors`
			...
372	421		`.word irq`
373	422
374	423		`; -----------------------------------------------------------------------------`
375		-	`; CHR-ROM`
	424	+	`; CHR-ROM - Background Tiles (Pattern Table 0)`
376	425		`; -----------------------------------------------------------------------------`
377	426		`.segment "CHARS"`
378		-
379		-	`; Tile 0: Empty (transparent)`
380		-	`.byte $00,$00,$00,$00,$00,$00,$00,$00`
381		-	`.byte $00,$00,$00,$00,$00,$00,$00,$00`
382		-
383		-	`; Tile 1: Border (solid cyan block)`
384		-	`.byte $00,$00,$00,$00,$00,$00,$00,$00 ; Low plane = 0`
385		-	`.byte $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF ; High plane = 1 (colour 2 = cyan)`
386	427
387		-	`; Tile 2: Floor (empty/dark)`
	428	+	`; Tile 0: Empty`
388	429		`.byte $00,$00,$00,$00,$00,$00,$00,$00`
389	430		`.byte $00,$00,$00,$00,$00,$00,$00,$00`
390	431
391		-	`; Tile 3: Player sprite (arrow)`
392		-	`.byte %00011000`
393		-	`.byte %00111100`
	432	+	`; Tile 1: Border (brick pattern)`
	433	+	`.byte %11111111 ; Row 0`
	434	+	`.byte %10000001 ; Row 1`
	435	+	`.byte %10000001 ; Row 2`
	436	+	`.byte %11111111 ; Row 3`
	437	+	`.byte %11111111 ; Row 4`
	438	+	`.byte %00010001 ; Row 5`
	439	+	`.byte %00010001 ; Row 6`
	440	+	`.byte %11111111 ; Row 7`
	441	+	`; High plane - add colour variation`
	442	+	`.byte %00000000`
394	443		`.byte %01111110`
395		-	`.byte %11111111`
396		-	`.byte %00111100`
397		-	`.byte %00111100`
398		-	`.byte %00111100`
399		-	`.byte %00111100`
	444	+	`.byte %01111110`
	445	+	`.byte %00000000`
	446	+	`.byte %00000000`
	447	+	`.byte %11101110`
	448	+	`.byte %11101110`
	449	+	`.byte %00000000`
	450	+
	451	+	`; Tile 2: Floor (subtle grid)`
	452	+	`.byte %00000000`
	453	+	`.byte %00000000`
	454	+	`.byte %00000000`
	455	+	`.byte %00000000`
	456	+	`.byte %00000000`
	457	+	`.byte %00000000`
	458	+	`.byte %00000000`
	459	+	`.byte %10000001`
	460	+	`; High plane`
400	461		`.byte %00000000`
401	462		`.byte %00000000`
402	463		`.byte %00000000`
			...
406	467		`.byte %00000000`
407	468		`.byte %00000000`
408	469
409		-	`; Fill rest of CHR-ROM`
410		-	`.res 8192 - 64, $00`
	470	+	`; Tile 3: Corner TL`
	471	+	`.byte %11111111`
	472	+	`.byte %11000000`
	473	+	`.byte %10100000`
	474	+	`.byte %10010000`
	475	+	`.byte %10001000`
	476	+	`.byte %10000100`
	477	+	`.byte %10000010`
	478	+	`.byte %10000001`
	479	+	`.byte %00000000`
	480	+	`.byte %00111111`
	481	+	`.byte %01011111`
	482	+	`.byte %01101111`
	483	+	`.byte %01110111`
	484	+	`.byte %01111011`
	485	+	`.byte %01111101`
	486	+	`.byte %01111110`
	487	+
	488	+	`; Tile 4: Corner TR`
	489	+	`.byte %11111111`
	490	+	`.byte %00000011`
	491	+	`.byte %00000101`
	492	+	`.byte %00001001`
	493	+	`.byte %00010001`
	494	+	`.byte %00100001`
	495	+	`.byte %01000001`
	496	+	`.byte %10000001`
	497	+	`.byte %00000000`
	498	+	`.byte %11111100`
	499	+	`.byte %11111010`
	500	+	`.byte %11110110`
	501	+	`.byte %11101110`
	502	+	`.byte %11011110`
	503	+	`.byte %10111110`
	504	+	`.byte %01111110`
	505	+
	506	+	`; Tile 5: Corner BL`
	507	+	`.byte %10000001`
	508	+	`.byte %10000010`
	509	+	`.byte %10000100`
	510	+	`.byte %10001000`
	511	+	`.byte %10010000`
	512	+	`.byte %10100000`
	513	+	`.byte %11000000`
	514	+	`.byte %11111111`
	515	+	`.byte %01111110`
	516	+	`.byte %01111101`
	517	+	`.byte %01111011`
	518	+	`.byte %01110111`
	519	+	`.byte %01101111`
	520	+	`.byte %01011111`
	521	+	`.byte %00111111`
	522	+	`.byte %00000000`
	523	+
	524	+	`; Tile 6: Corner BR`
	525	+	`.byte %10000001`
	526	+	`.byte %01000001`
	527	+	`.byte %00100001`
	528	+	`.byte %00010001`
	529	+	`.byte %00001001`
	530	+	`.byte %00000101`
	531	+	`.byte %00000011`
	532	+	`.byte %11111111`
	533	+	`.byte %01111110`
	534	+	`.byte %10111110`
	535	+	`.byte %11011110`
	536	+	`.byte %11101110`
	537	+	`.byte %11110110`
	538	+	`.byte %11111010`
	539	+	`.byte %11111100`
	540	+	`.byte %00000000`
	541	+
	542	+	`; Sprite 0: Player (better ship design) - at tile index 0 in sprite table`
	543	+	`; This goes immediately after background tiles`
	544	+	`.byte %00011000 ; Row 0`
	545	+	`.byte %00011000 ; Row 1`
	546	+	`.byte %00111100 ; Row 2`
	547	+	`.byte %01111110 ; Row 3`
	548	+	`.byte %11111111 ; Row 4`
	549	+	`.byte %10111101 ; Row 5`
	550	+	`.byte %00100100 ; Row 6`
	551	+	`.byte %00100100 ; Row 7`
	552	+	`; High plane`
	553	+	`.byte %00000000`
	554	+	`.byte %00011000`
	555	+	`.byte %00011000`
	556	+	`.byte %00111100`
	557	+	`.byte %01000010`
	558	+	`.byte %01000010`
	559	+	`.byte %00011000`
	560	+	`.byte %00000000`
	561	+
	562	+	`; Fill rest of CHR-ROM (8KB total = 8192 bytes, used 128 so far)`
	563	+	`.res 8192 - 128, $00`
411	564