Game 1 Unit 4 of 64 1 hr learning time

The Background

Draw a bordered arena using the nametable.

6% of Neon Nexus

Mark as complete Completed!

What You’re Building

A bordered play area. The player is now confined to an arena.

The Arena

This is the game world taking shape.

The Nametable

The NES background is a 32×30 grid of tile indices. Each byte in the nametable references a tile from the pattern table.

Nametable starts at $2000
960 bytes total (32 × 30)
Each byte = one 8×8 tile

To draw the arena, we fill this grid with border and floor tiles.

Drawing the Arena

draw_arena:
    ; Set PPU address to nametable start
    lda #$20
    sta PPUADDR
    lda #$00
    sta PPUADDR

    ; Draw 30 rows
    ldy #0

@draw_row:
    ; First/last 2 rows are all border
    cpy #0
    beq @border_row
    cpy #1
    beq @border_row
    cpy #28
    beq @border_row
    cpy #29
    beq @border_row

    ; Middle rows: border + floor + border
    jmp @middle_row

The PPU address auto-increments after each write to PPUDATA. Write 960 tiles and you’ve filled the screen.

Tile Layout

We define three tiles in CHR-ROM:

Tile	Purpose	Appearance
0	Empty	Transparent
1	Border	Solid cyan
2	Floor	Black
3	Player	Arrow sprite

The Code

; =============================================================================
; NEON NEXUS - Unit 4: The Background
; =============================================================================
; Add a bordered arena using the nametable.
; =============================================================================

; -----------------------------------------------------------------------------
; 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
TILE_EMPTY  = 0
TILE_BORDER = 1
TILE_FLOOR  = 2
TILE_PLAYER = 3

; Arena boundaries (in pixels, accounting for border)
ARENA_LEFT   = 16    ; 2 border tiles × 8
ARENA_RIGHT  = 232   ; 256 - 16 - 8 (sprite width)
ARENA_TOP    = 16
ARENA_BOTTOM = 208   ; 240 - 16 - 16 (overscan + border)

; Palette
BG_COLOUR = $0F      ; Black background

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

    ; Load palette
    jsr load_palette

    ; Draw the arena
    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 #TILE_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

    ; Reset scroll
    lda #0
    sta PPUSCROLL
    sta PPUSCROLL

    ; Enable rendering
    lda #%10000000    ; NMI on, background and sprites from pattern table 0
    sta PPUCTRL
    lda #%00011110    ; Show sprites and background
    sta PPUMASK

; === Main Loop ===
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
; -----------------------------------------------------------------------------
draw_arena:
    ; Set PPU address to start of nametable ($2000)
    bit PPUSTATUS
    lda #$20
    sta PPUADDR
    lda #$00
    sta PPUADDR

    ; Draw 30 rows
    ldy #0              ; Row counter

@draw_row:
    ; Check if first row, last row, or middle
    cpy #0
    beq @border_row
    cpy #1
    beq @border_row
    cpy #28
    beq @border_row
    cpy #29
    beq @border_row

    ; Middle row: border + floor + border
    jmp @middle_row

@border_row:
    ; All border tiles
    ldx #32
@border_loop:
    lda #TILE_BORDER
    sta PPUDATA
    dex
    bne @border_loop
    jmp @next_row

@middle_row:
    ; Left border (2 tiles)
    lda #TILE_BORDER
    sta PPUDATA
    sta PPUDATA

    ; Floor (28 tiles)
    ldx #28
@floor_loop:
    lda #TILE_FLOOR
    sta PPUDATA
    dex
    bne @floor_loop

    ; Right border (2 tiles)
    lda #TILE_BORDER
    sta PPUDATA
    sta PPUDATA

@next_row:
    iny
    cpy #30
    bne @draw_row

    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:
    ; UP
    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

    ; DMA sprites
    lda #0
    sta OAMADDR
    lda #>oam_buffer
    sta OAMDMA

    ; Update sprite position
    lda player_y
    sta oam_buffer+0
    lda player_x
    sta oam_buffer+3

    ; Reset scroll (important after any PPU access)
    lda #0
    sta PPUSCROLL
    sta PPUSCROLL

    pla
    tay
    pla
    tax
    pla
    rti

irq:
    rti

; -----------------------------------------------------------------------------
; Data
; -----------------------------------------------------------------------------
palette_data:
    ; Background palettes
    .byte BG_COLOUR, $12, $21, $30  ; Palette 0: black, blue, cyan (border), white
    .byte BG_COLOUR, $12, $21, $30  ; Palette 1
    .byte BG_COLOUR, $12, $21, $30  ; Palette 2
    .byte BG_COLOUR, $12, $21, $30  ; Palette 3
    ; Sprite palettes
    .byte BG_COLOUR, $30, $20, $16  ; Palette 0: black, white, red, orange
    .byte BG_COLOUR, $30, $20, $16  ; Palette 1
    .byte BG_COLOUR, $30, $20, $16  ; Palette 2
    .byte BG_COLOUR, $30, $20, $16  ; Palette 3

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

; -----------------------------------------------------------------------------
; CHR-ROM
; -----------------------------------------------------------------------------
.segment "CHARS"

; Tile 0: Empty (transparent)
.byte $00,$00,$00,$00,$00,$00,$00,$00
.byte $00,$00,$00,$00,$00,$00,$00,$00

; Tile 1: Border (solid cyan block)
.byte $00,$00,$00,$00,$00,$00,$00,$00  ; Low plane = 0
.byte $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF  ; High plane = 1 (colour 2 = cyan)

; Tile 2: Floor (empty/dark)
.byte $00,$00,$00,$00,$00,$00,$00,$00
.byte $00,$00,$00,$00,$00,$00,$00,$00

; Tile 3: Player sprite (arrow)
.byte %00011000
.byte %00111100
.byte %01111110
.byte %11111111
.byte %00111100
.byte %00111100
.byte %00111100
.byte %00111100
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000
.byte %00000000

; Fill rest of CHR-ROM
.res 8192 - 64, $00

Build It

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

Move with the D-pad. The player now bounces off the arena walls.

Updated Boundaries

The movement code now uses arena boundaries instead of screen edges:

ARENA_LEFT   = 16    ; 2 border tiles × 8 pixels
ARENA_RIGHT  = 232
ARENA_TOP    = 16
ARENA_BOTTOM = 208

The player can’t escape the play area.

The arena works but looks plain. Unit 5 adds custom tile graphics.

What Changed

Unit 3 → Unit 4

+158-67

1	1		`; =============================================================================`
2		-	`; NEON NEXUS - Unit 2: Moving the Player`
	2	+	`; NEON NEXUS - Unit 4: The Background`
3	3		`; =============================================================================`
4		-	`; The player sprite now moves with the D-pad.`
5		-	`; Press Up, Down, Left, Right to move around the screen.`
	4	+	`; Add a bordered arena using the nametable.`
6	5		`; =============================================================================`
7	6
8	7		`; -----------------------------------------------------------------------------`
			...
12	11		`PPUMASK = $2001`
13	12		`PPUSTATUS = $2002`
14	13		`OAMADDR = $2003`
	14	+	`PPUSCROLL = $2005`
15	15		`PPUADDR = $2006`
16	16		`PPUDATA = $2007`
17	17		`OAMDMA = $4014`
18	18
19		-	`JOYPAD1 = $4016 ; Controller 1`
20		-	`JOYPAD2 = $4017 ; Controller 2`
	19	+	`JOYPAD1 = $4016`
	20	+	`JOYPAD2 = $4017`
21	21
22		-	`; Controller button masks`
	22	+	`; Controller buttons`
23	23		`BTN_A = %10000000`
24	24		`BTN_B = %01000000`
25	25		`BTN_SELECT = %00100000`
			...
34	34		`; -----------------------------------------------------------------------------`
35	35		`PLAYER_START_X = 124`
36	36		`PLAYER_START_Y = 116`
37		-	`PLAYER_TILE = 1`
38		-	`BG_COLOUR = $12`
	37	+	`PLAYER_SPEED = 2`
39	38
40		-	`PLAYER_SPEED = 2 ; Pixels per frame (try 1, 2, or 3)`
	39	+	`; Tile indices`
	40	+	`TILE_EMPTY = 0`
	41	+	`TILE_BORDER = 1`
	42	+	`TILE_FLOOR = 2`
	43	+	`TILE_PLAYER = 3`
41	44
42		-	`; Screen boundaries`
43		-	`SCREEN_LEFT = 0`
44		-	`SCREEN_RIGHT = 248 ; 256 - 8 (sprite width)`
45		-	`SCREEN_TOP = 0`
46		-	`SCREEN_BOTTOM = 224 ; 240 - 16 (sprite height + overscan)`
	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	+	`ARENA_TOP = 16`
	49	+	`ARENA_BOTTOM = 208 ; 240 - 16 - 16 (overscan + border)`
	50	+
	51	+	`; Palette`
	52	+	`BG_COLOUR = $0F ; Black background`
47	53
48	54		`; -----------------------------------------------------------------------------`
49	55		`; Memory Layout`
			...
51	57		`.segment "ZEROPAGE"`
52	58		`player_x: .res 1`
53	59		`player_y: .res 1`
54		-	`buttons: .res 1 ; Current button state`
	60	+	`buttons: .res 1`
	61	+	`temp: .res 1`
55	62
56	63		`.segment "OAM"`
57	64		`oam_buffer: .res 256`
			...
63	70		`; -----------------------------------------------------------------------------`
64	71		`.segment "HEADER"`
65	72		`.byte "NES", $1A`
66		-	`.byte 2 ; 32KB PRG-ROM`
67		-	`.byte 1 ; 8KB CHR-ROM`
68		-	`.byte $01 ; Mapper 0, vertical mirroring`
	73	+	`.byte 2`
	74	+	`.byte 1`
	75	+	`.byte $01`
69	76		`.byte $00`
70	77		`.byte 0,0,0,0,0,0,0,0`
71	78
			...
108	115		`bpl @vblank2`
109	116
110	117		`; Load palette`
111		-	`bit PPUSTATUS`
112		-	`lda #$3F`
113		-	`sta PPUADDR`
114		-	`lda #$00`
115		-	`sta PPUADDR`
	118	+	`jsr load_palette`
116	119
117		-	`ldx #0`
118		-	`@load_palette:`
119		-	`lda palette_data, x`
120		-	`sta PPUDATA`
121		-	`inx`
122		-	`cpx #32`
123		-	`bne @load_palette`
	120	+	`; Draw the arena`
	121	+	`jsr draw_arena`
124	122
125	123		`; Set up player`
126	124		`lda #PLAYER_START_X`
			...
131	129		`; Initialise player sprite`
132	130		`lda player_y`
133	131		`sta oam_buffer+0`
134		-	`lda #PLAYER_TILE`
	132	+	`lda #TILE_PLAYER`
135	133		`sta oam_buffer+1`
136	134		`lda #0`
137	135		`sta oam_buffer+2`
			...
145	143		`sta oam_buffer, x`
146	144		`inx`
147	145		`bne @hide_sprites`
	146	+
	147	+	`; Reset scroll`
	148	+	`lda #0`
	149	+	`sta PPUSCROLL`
	150	+	`sta PPUSCROLL`
148	151
149	152		`; Enable rendering`
150		-	`lda #%10010000`
	153	+	`lda #%10000000 ; NMI on, background and sprites from pattern table 0`
151	154		`sta PPUCTRL`
152		-	`lda #%00011110`
	155	+	`lda #%00011110 ; Show sprites and background`
153	156		`sta PPUMASK`
154	157
155	158		`; === Main Loop ===`
156	159		`main_loop:`
157		-	`; Read controller`
158	160		`jsr read_controller`
159		-
160		-	`; Move player based on input`
161	161		`jsr move_player`
162		-
163	162		`jmp main_loop`
	163	+
	164	+	`; -----------------------------------------------------------------------------`
	165	+	`; Load Palette`
	166	+	`; -----------------------------------------------------------------------------`
	167	+	`load_palette:`
	168	+	`bit PPUSTATUS`
	169	+	`lda #$3F`
	170	+	`sta PPUADDR`
	171	+	`lda #$00`
	172	+	`sta PPUADDR`
	173	+
	174	+	`ldx #0`
	175	+	`@loop:`
	176	+	`lda palette_data, x`
	177	+	`sta PPUDATA`
	178	+	`inx`
	179	+	`cpx #32`
	180	+	`bne @loop`
	181	+	`rts`
	182	+
	183	+	`; -----------------------------------------------------------------------------`
	184	+	`; Draw Arena`
	185	+	`; -----------------------------------------------------------------------------`
	186	+	`draw_arena:`
	187	+	`; Set PPU address to start of nametable ($2000)`
	188	+	`bit PPUSTATUS`
	189	+	`lda #$20`
	190	+	`sta PPUADDR`
	191	+	`lda #$00`
	192	+	`sta PPUADDR`
	193	+
	194	+	`; Draw 30 rows`
	195	+	`ldy #0 ; Row counter`
	196	+
	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`
	207	+
	208	+	`; Middle row: border + floor + border`
	209	+	`jmp @middle_row`
	210	+
	211	+	`@border_row:`
	212	+	`; All border tiles`
	213	+	`ldx #32`
	214	+	`@border_loop:`
	215	+	`lda #TILE_BORDER`
	216	+	`sta PPUDATA`
	217	+	`dex`
	218	+	`bne @border_loop`
	219	+	`jmp @next_row`
	220	+
	221	+	`@middle_row:`
	222	+	`; Left border (2 tiles)`
	223	+	`lda #TILE_BORDER`
	224	+	`sta PPUDATA`
	225	+	`sta PPUDATA`
	226	+
	227	+	`; Floor (28 tiles)`
	228	+	`ldx #28`
	229	+	`@floor_loop:`
	230	+	`lda #TILE_FLOOR`
	231	+	`sta PPUDATA`
	232	+	`dex`
	233	+	`bne @floor_loop`
	234	+
	235	+	`; Right border (2 tiles)`
	236	+	`lda #TILE_BORDER`
	237	+	`sta PPUDATA`
	238	+	`sta PPUDATA`
	239	+
	240	+	`@next_row:`
	241	+	`iny`
	242	+	`cpy #30`
	243	+	`bne @draw_row`
	244	+
	245	+	`rts`
164	246
165	247		`; -----------------------------------------------------------------------------`
166	248		`; Read Controller`
167	249		`; -----------------------------------------------------------------------------`
168	250		`read_controller:`
169		-	`; Strobe the controller`
170	251		`lda #1`
171	252		`sta JOYPAD1`
172	253		`lda #0`
173	254		`sta JOYPAD1`
174	255
175		-	`; Read 8 buttons into 'buttons' variable`
176	256		`ldx #8`
177	257		`@read_loop:`
178	258		`lda JOYPAD1`
179		-	`lsr a ; Bit 0 -> Carry`
180		-	`rol buttons ; Carry -> buttons`
	259	+	`lsr a`
	260	+	`rol buttons`
181	261		`dex`
182	262		`bne @read_loop`
183		-
184	263		`rts`
185	264
186	265		`; -----------------------------------------------------------------------------`
187	266		`; Move Player`
188	267		`; -----------------------------------------------------------------------------`
189	268		`move_player:`
190		-	`; Check UP`
	269	+	`; UP`
191	270		`lda buttons`
192	271		`and #BTN_UP`
193	272		`beq @check_down`
194		-
195	273		`lda player_y`
196	274		`sec`
197	275		`sbc #PLAYER_SPEED`
198		-	`cmp #SCREEN_TOP`
199		-	`bcc @check_down ; Don't go above top`
	276	+	`cmp #ARENA_TOP`
	277	+	`bcc @check_down`
200	278		`sta player_y`
201	279
202	280		`@check_down:`
203	281		`lda buttons`
204	282		`and #BTN_DOWN`
205	283		`beq @check_left`
206		-
207	284		`lda player_y`
208	285		`clc`
209	286		`adc #PLAYER_SPEED`
210		-	`cmp #SCREEN_BOTTOM`
211		-	`bcs @check_left ; Don't go below bottom`
	287	+	`cmp #ARENA_BOTTOM`
	288	+	`bcs @check_left`
212	289		`sta player_y`
213	290
214	291		`@check_left:`
215	292		`lda buttons`
216	293		`and #BTN_LEFT`
217	294		`beq @check_right`
218		-
219	295		`lda player_x`
220	296		`sec`
221	297		`sbc #PLAYER_SPEED`
222		-	`cmp #SCREEN_LEFT`
223		-	`bcc @check_right ; Don't go past left edge`
	298	+	`cmp #ARENA_LEFT`
	299	+	`bcc @check_right`
224	300		`sta player_x`
225	301
226	302		`@check_right:`
227	303		`lda buttons`
228	304		`and #BTN_RIGHT`
229	305		`beq @done`
230		-
231	306		`lda player_x`
232	307		`clc`
233	308		`adc #PLAYER_SPEED`
234		-	`cmp #SCREEN_RIGHT`
235		-	`bcs @done ; Don't go past right edge`
	309	+	`cmp #ARENA_RIGHT`
	310	+	`bcs @done`
236	311		`sta player_x`
237	312
238	313		`@done:`
			...
252	327		`lda #>oam_buffer`
253	328		`sta OAMDMA`
254	329
255		-	`; Update sprite from player position`
	330	+	`; Update sprite position`
256	331		`lda player_y`
257	332		`sta oam_buffer+0`
258	333		`lda player_x`
259	334		`sta oam_buffer+3`
	335	+
	336	+	`; Reset scroll (important after any PPU access)`
	337	+	`lda #0`
	338	+	`sta PPUSCROLL`
	339	+	`sta PPUSCROLL`
260	340
261	341		`pla`
262	342		`tay`
			...
272	352		`; Data`
273	353		`; -----------------------------------------------------------------------------`
274	354		`palette_data:`
275		-	`.byte BG_COLOUR, $00, $10, $20`
276		-	`.byte BG_COLOUR, $00, $10, $20`
277		-	`.byte BG_COLOUR, $00, $10, $20`
278		-	`.byte BG_COLOUR, $00, $10, $20`
279		-	`.byte BG_COLOUR, $30, $20, $0F`
280		-	`.byte BG_COLOUR, $30, $16, $0F`
281		-	`.byte BG_COLOUR, $30, $12, $0F`
282		-	`.byte BG_COLOUR, $30, $14, $0F`
	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`
	360	+	`; 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`
283	365
284	366		`; -----------------------------------------------------------------------------`
285	367		`; Vectors`
			...
294	376		`; -----------------------------------------------------------------------------`
295	377		`.segment "CHARS"`
296	378
297		-	`; Tile 0: Empty`
	379	+	`; Tile 0: Empty (transparent)`
298	380		`.byte $00,$00,$00,$00,$00,$00,$00,$00`
299	381		`.byte $00,$00,$00,$00,$00,$00,$00,$00`
300	382
301		-	`; Tile 1: Player sprite`
	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	+
	387	+	`; Tile 2: Floor (empty/dark)`
	388	+	`.byte $00,$00,$00,$00,$00,$00,$00,$00`
	389	+	`.byte $00,$00,$00,$00,$00,$00,$00,$00`
	390	+
	391	+	`; Tile 3: Player sprite (arrow)`
302	392		`.byte %00011000`
303	393		`.byte %00111100`
304	394		`.byte %01111110`
			...
316	406		`.byte %00000000`
317	407		`.byte %00000000`
318	408
319		-	`.res 8192 - 32, $00`
	409	+	`; Fill rest of CHR-ROM`
	410	+	`.res 8192 - 64, $00`
320	411