diff --git a/assemble.sh b/assemble.sh
new file mode 100644
index 0000000..4f3df48
--- /dev/null
+++ b/assemble.sh
@@ -0,0 +1,5 @@
+#! /bin/sh
+
+ca65 src/helloworld.asm
+ca65 src/reset.asm
+ld65 src/reset.o src/helloworld.o -C nes.cfg -o helloworld.nes
diff --git a/helloworld.nes b/helloworld.nes
new file mode 100644
index 0000000..6e3e5ce
Binary files /dev/null and b/helloworld.nes differ
diff --git a/nes.cfg b/nes.cfg
new file mode 100644
index 0000000..12f8cf4
--- /dev/null
+++ b/nes.cfg
@@ -0,0 +1,22 @@
+MEMORY {
+  HEADER: start=$00, size=$10, fill=yes, fillval=$00;
+  ZEROPAGE: start=$10, size=$ff;
+  STACK: start=$0100, size=$0100;
+  OAMBUFFER: start=$0200, size=$0100;
+  RAM: start=$0300, size=$0500;
+  ROM: start=$8000, size=$8000, fill=yes, fillval=$ff;
+  CHRROM: start=$0000, size=$2000;
+}
+
+SEGMENTS {
+  HEADER: load=HEADER, type=ro, align=$10;
+  ZEROPAGE: load=ZEROPAGE, type=zp;
+  STACK: load=STACK, type=bss, optional=yes;
+  OAM: load=OAMBUFFER, type=bss, optional=yes;
+  BSS: load=RAM, type=bss, optional=yes;
+  DMC: load=ROM, type=ro, align=64, optional=yes;
+  CODE: load=ROM, type=ro, align=$0100;
+  RODATA: load=ROM, type=ro, align=$0100;
+  VECTORS: load=ROM, type=ro, start=$FFFA;
+  CHR: load=CHRROM, type=ro, align=16, optional=yes;
+}
\ No newline at end of file
diff --git a/src/background.nam b/src/background.nam
new file mode 100644
index 0000000..bbfc52f
Binary files /dev/null and b/src/background.nam differ
diff --git a/src/constants.inc b/src/constants.inc
new file mode 100644
index 0000000..5acaec0
--- /dev/null
+++ b/src/constants.inc
@@ -0,0 +1,7 @@
+PPUCTRL   = $2000
+PPUMASK   = $2001
+PPUSTATUS = $2002
+PPUADDR   = $2006
+PPUDATA   = $2007
+OAMADDR   = $2003
+OAMDMA    = $4014
\ No newline at end of file
diff --git a/src/header.inc b/src/header.inc
new file mode 100644
index 0000000..fe09113
--- /dev/null
+++ b/src/header.inc
@@ -0,0 +1,8 @@
+.segment "HEADER"
+.byte $4e, $45, $53, $1a ; Magic string that always begins an iNES header
+.byte $02        ; Number of 16KB PRG-ROM banks
+.byte $01        ; Number of 8KB CHR-ROM banks
+.byte %00000001  ; Vertical mirroring, no save RAM, no mapper
+.byte %00000000  ; No special-case flags set, no mapper
+.byte $00        ; No PRG-RAM present
+.byte $00        ; NTSC format
\ No newline at end of file
diff --git a/src/helloworld.asm b/src/helloworld.asm
new file mode 100644
index 0000000..b5ffd6a
--- /dev/null
+++ b/src/helloworld.asm
@@ -0,0 +1,421 @@
+.include "constants.inc"
+.include "header.inc"
+
+.segment "CODE"
+.proc irq_handler
+  RTI
+.endproc
+
+.proc nmi_handler
+  LDA #$00
+  STA OAMADDR
+  LDA #$02
+  STA OAMDMA
+
+  ;Update tiles *after* DMA transfer
+  JSR update_player
+  JSR draw_player
+
+  LDA #$00
+  STA $2005
+  STA $2005
+  RTI
+.endproc
+
+.import reset_handler
+
+
+.proc draw_player
+  ;save registers
+  PHP
+  PHA
+  TXA
+  PHA
+  TYA
+  PHA
+
+  ;write player ship tile numbers
+
+  LDA #$05
+  STA $0201
+  LDA #$06
+  STA $0205
+  LDA #$07
+  STA $0209
+  LDA #$08
+  STA $020D
+
+  ; write player ship tile attributes
+  ; use palette 0
+  LDA #$00
+  STA $0202
+  STA $0206
+  STA $020A
+  STA $020E
+
+  ; store tile locations
+  ; top left tile:
+  LDA player_y
+  STA $0200
+  LDA player_x
+  STA $0203
+
+  ;top right tile (x+8):
+  LDA player_y
+  STA $0204
+  LDA player_x
+  CLC
+  ADC #$08
+  STA $0207
+
+  ;bottom left tile (y+8)
+  LDA player_y
+  CLC
+  ADC #$08
+  STA $0208
+  LDA player_x
+  STA $020B
+
+  ;bottom right tile (x+8, y+8)
+  LDA player_y
+  CLC
+  ADC #$08
+  STA $020C
+  LDA player_x
+  CLC
+  ADC #$08
+  STA $020F
+
+  ; restore registers and return
+  PLA
+  TAY
+  PLA
+  TAX
+  PLA
+  PLP
+  RTS
+.endproc
+
+.proc update_player
+  PHP
+  PHA
+  TXA
+  PHA
+  TYA
+  PHA
+
+  LDA player_x
+  CMP #$e0
+  BCC not_at_right_edge
+  ; if BCC is not taken, we are greater than $e0
+  LDA #$00
+  STA player_dir    ; start moving left
+  JMP direction_set ; we already chose a direction,
+                    ; so we can skip the left side check
+not_at_right_edge:
+  LDA player_x
+  CMP #$10
+  BCS direction_set
+  ; if BCS not taken, we are less than $10
+  LDA #$01
+  STA player_dir ; start moving right
+direction_set:
+  ; now, actually update player_x
+  LDA player_dir
+  CMP #$01
+  BEQ move_right
+  ; if player_dir minus $01 is not zero,
+  ; that means player_dir was $00 and
+  ; we need to move left
+  DEC player_x
+  JMP exit_subroutine
+move_right:
+  INC player_x
+exit_subroutine:
+  ; all done, clean up an return
+  PLA
+  TAY
+  PLA
+  TAX
+  PLA
+  PLP 
+  RTS
+.endproc
+
+.export main
+.proc main
+
+  LDX PPUSTATUS
+  LDX #$3f
+  STX PPUADDR
+  LDX #$00
+  STX PPUADDR
+
+  LDX #$00
+load_palettes:
+  LDA palettes,X
+  STA PPUDATA
+  INX
+  CPX #$20
+  BNE load_palettes
+
+  LDX #$00
+
+  ; write a nametable
+  ; Big Stars
+
+  LDA PPUSTATUS
+  LDA #$21
+  STA PPUADDR
+  LDA #$72
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$20
+  STA PPUADDR
+  LDA #$68
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$20
+  STA PPUADDR
+  LDA #$74
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$21
+  STA PPUADDR
+  LDA #$5A
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$21
+  STA PPUADDR
+  LDA #$CB
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$21
+  STA PPUADDR
+  LDA #$64
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$22
+  STA PPUADDR
+  LDA #$C7
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$22
+  STA PPUADDR
+  LDA #$55
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$22
+  STA PPUADDR
+  LDA #$B9
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$23
+  STA PPUADDR
+  LDA #$6D
+  STA PPUADDR
+  LDX #$2F
+  STX PPUDATA
+
+  ; write a nametable
+  ; Medium Stars
+
+  LDA PPUSTATUS
+  LDA #$20
+  STA PPUADDR
+  LDA #$64
+  STA PPUADDR
+  LDX #$2D
+  STX PPUDATA
+  
+  LDA PPUSTATUS
+  LDA #$20
+  STA PPUADDR
+  LDA #$4F
+  STA PPUADDR
+  LDX #$2D
+  STX PPUDATA
+  
+  LDA PPUSTATUS
+  LDA #$20
+  STA PPUADDR
+  LDA #$B9
+  STA PPUADDR
+  LDX #$2D
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$20
+  STA PPUADDR
+  LDA #$DD
+  STA PPUADDR
+  LDX #$2D
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$21
+  STA PPUADDR
+  LDA #$4D
+  STA PPUADDR
+  LDX #$2D
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$20
+  STA PPUADDR
+  LDA #$D1
+  STA PPUADDR
+  LDX #$2D
+  STX PPUDATA
+
+  ; write a nametable
+  ; Small Stars
+  LDA PPUSTATUS
+  LDA #$20
+  STA PPUADDR
+  LDA #$3A
+  STA PPUADDR
+  LDX #$2E
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$20
+  STA PPUADDR
+  LDA #$B9
+  STA PPUADDR
+  LDX #$2E
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$21
+  STA PPUADDR
+  LDA #$4D
+  STA PPUADDR
+  LDX #$2E
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$21
+  STA PPUADDR
+  LDA #$4D
+  STA PPUADDR
+  LDX #$2E
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$21
+  STA PPUADDR
+  LDA #$F0
+  STA PPUADDR
+  LDX #$2E
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$22
+  STA PPUADDR
+  LDA #$26
+  STA PPUADDR
+  LDX #$2E
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$22
+  STA PPUADDR
+  LDA #$E4
+  STA PPUADDR
+  LDX #$2E
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$22
+  STA PPUADDR
+  LDA #$CE
+  STA PPUADDR
+  LDX #$2E
+  STX PPUDATA
+
+  LDA PPUSTATUS
+  LDA #$23
+  STA PPUADDR
+  LDA #$36
+  STA PPUADDR
+  LDX #$2E
+  STX PPUDATA
+
+  ; finally, attribute table
+	LDA PPUSTATUS
+	LDA #$23
+	STA PPUADDR
+	LDA #$D4
+	STA PPUADDR
+	LDA #%01110000
+	STA PPUDATA
+
+vblankwait: ; wait for another vblank before continuing
+  BIT PPUSTATUS 
+  BPL vblankwait
+
+  LDA #%10010000 ; turn on NMIs, sprites use first pattern table
+  STA PPUCTRL
+  LDA #%00011110 ; turn on screen
+  STA PPUMASK
+forever:
+  JMP forever
+.endproc
+
+.segment "ZEROPAGE"
+player_x: .res 1
+player_y: .res 1
+player_dir: .res 1
+.exportzp player_x, player_y
+
+.segment "RODATA"
+palettes:
+  .byte $0f, $12, $23, $27
+  .byte $0f, $2b, $3c, $39
+  .byte $0f, $0c, $07, $13
+  .byte $0f, $19, $09, $29
+
+  .byte $0f, $2d, $10, $15
+  .byte $0f, $19, $09, $29
+  .byte $0f, $19, $09, $29
+  .byte $0f, $19, $09, $29
+
+sprite:
+  .byte $70, $05, $00, $80
+  .byte $70, $06, $00, $88
+  .byte $78, $07, $00, $80
+  .byte $78, $08, $00, $88
+
+.segment "VECTORS"
+.addr nmi_handler, reset_handler, irq_handler
+
+.segment "CHR"
+.incbin "starfield.chr"
\ No newline at end of file
diff --git a/src/helloworld.o b/src/helloworld.o
new file mode 100644
index 0000000..c0e2b20
Binary files /dev/null and b/src/helloworld.o differ
diff --git a/src/reset.asm b/src/reset.asm
new file mode 100644
index 0000000..cd67c3c
--- /dev/null
+++ b/src/reset.asm
@@ -0,0 +1,43 @@
+.include "constants.inc"
+
+.segment "ZEROPAGE"
+.importzp player_x, player_y
+
+.segment "CODE"
+.import main
+.export reset_handler
+.proc reset_handler
+  SEI
+  CLD
+  LDX #$40
+  STX $4017
+  LDX #$FF
+  TXS
+  INX
+  STX PPUCTRL
+  STX PPUMASK
+  STX $4010
+  BIT PPUSTATUS
+vblankwait:
+  BIT PPUSTATUS
+  BPL vblankwait
+
+  LDX #$00
+  LDA #$FF
+clear_oam:
+  STA $0200, X
+  INX
+  INX
+  INX
+  INX
+  BNE clear_oam
+vblankwait2:
+  BIT PPUSTATUS
+  BPL vblankwait2
+  ; initialize zero-page values
+  LDA #$80
+  STA player_x
+  LDA #$a0
+  STA player_y
+  JMP main
+.endproc
\ No newline at end of file
diff --git a/src/reset.o b/src/reset.o
new file mode 100644
index 0000000..0e5078a
Binary files /dev/null and b/src/reset.o differ
diff --git a/src/starfield.chr b/src/starfield.chr
new file mode 100644
index 0000000..6562607
Binary files /dev/null and b/src/starfield.chr differ