diff --git a/code/factorial/factorial.s b/code/factorial/factorial.s
index c5cc41d..6c243b3 100644
--- a/code/factorial/factorial.s
+++ b/code/factorial/factorial.s
@@ -1,5 +1,5 @@
 .psx
-.create "factorial.bin", 0x80010000
+.create "./build/factorial.bin", 0x80010000
 
 ; Entry Point of Code
 .org 0x80010000
diff --git a/code/graphics_system/dsl.s b/code/graphics_system/dsl.s
new file mode 100644
index 0000000..d27b766
--- /dev/null
+++ b/code/graphics_system/dsl.s
@@ -0,0 +1,44 @@
+; Symbol Alias Table
+
+; Instructions
+; Load
+load_imm   equ li  ; dst_reg, immeidate value (signed)
+load_uimm  equ lui ; dst_reg, immediate value (unsigned)
+; Store
+store_word equ sw ; src_reg, dst_address 
+; Addition
+add_s  equ add   ; dst_reg, reg_a, reg_b (signed)
+add_u  equ add   ; dst_reg, reg_a, reg_b (unsigned)
+add_si equ addi  ; dst_reg, src_reg, immediate value (signed)
+add_ui equ addiu ; dst_reg, src_reg, immediate value (unsigned)
+; Subtraction
+sub_s equ sub    ; 
+sub_u equ subu   ; 
+; Branch
+branch_equal    equ beq ; reg, value(reg, immediate), dst_label
+branch_gt_equal equ bge ; reg, value(reg, immediate), dst_label
+branch_gt       equ bgt ; reg, value(reg, immediate), dst_label
+branch_lt       equ blt ; reg, value(reg, immediate), dst_label
+; Jump
+jump       equ j   ; address:    immediate
+jump_nlink equ jal ; subroutine: immeidate
+jump_reg   equ jr  ; address:    register
+jump_nreg  equ jrl ; subroutine: register
+
+; Registers
+; Temporaries, may be changed by subroutines
+rtmp_0 equ $t0
+rtmp_1 equ $t1
+rtmp_2 equ $t2
+rtmp_3 equ $t3
+rtmp_4 equ $t4
+; Subroutine arguments
+rarg_0 equ $a0
+rarg_1 equ $a1
+rarg_2 equ $a2
+rarg_3 equ $a3
+; Subroutine return values
+rret_0 equ $v0
+rret_1 equ $v1
+; Subroutine return address when doing a sub
+rret_addr equ $ra
\ No newline at end of file
diff --git a/code/graphics_system/hellogpu.s b/code/graphics_system/hellogpu.s
new file mode 100644
index 0000000..4184c30
--- /dev/null
+++ b/code/graphics_system/hellogpu.s
@@ -0,0 +1,155 @@
+.psx
+.create "./build/hellogpu.bin", 0x80010000
+
+.include "./code/graphics_system/dsl.s"
+
+; Entry Point of Code
+.org 0x80010000
+
+; IO PORT
+IO_BASE_ADDR equ 0x1F80 ; IO Ports Memory map base address
+
+; GPU Registers
+gpio_port0 equ 0x1810 ; 1F801810h-Write GP0: Send GP0 Commands/Packets (Rendering and VRAM Access)
+gpio_port1 equ 0x1814 ; 1F801814h-Write GP1: Send GP1 Commands (Display Control) (and DMA Control)
+
+; GPU Display Control Command Format: [7:8] Command (8-bit), [0:6] Paraemter (24-bit)
+
+gcmd_offset equ 24
+
+; On:  0x0
+; Off: 0x1
+gp_DisplayEnabled                 equ (0x03 << gcmd_offset)  | 0x0
+gp_DisplayDisabled                equ (0x03 << gcmd_offset)  | 0x1
+
+; GP1(08h) - Display mode
+; 0-1   Horizontal Resolution 1     (0=256, 1=320, 2=512, 3=640) ;GPUSTAT.17-18
+; 2     Vertical Resolution         (0=240, 1=480, when Bit5=1)  ;GPUSTAT.19
+; 3     Video Mode                  (0=NTSC/60Hz, 1=PAL/50Hz)    ;GPUSTAT.20
+; 4     Display Area Color Depth    (0=15bit, 1=24bit)           ;GPUSTAT.21
+; 5     Vertical Interlace          (0=Off, 1=On)                ;GPUSTAT.22
+; 6     Horizontal Resolution 2     (0=256/320/512/640, 1=368)   ;GPUSTAT.16
+; 7     Flip screen horizontally    (0=Off, 1=On, v1 only)       ;GPUSTAT.14
+; 8-23  Not used (zero)
+@DisplayMode equ 0x08
+gp_DisplayMode_320x240_15bit_NTSC equ @DisplayMode << gcmd_offset | 0x0 << 7 | 0x0 << 6 | 0x0 << 5 | 0x0 << 4 | 0x0 << 3 | 0x0 << 2 | 0x1
+
+; GP1(06h) - Horizontal Display range (on Screen)
+; X2 = X1 + pixels * cycles_per_pix
+; 0  - 11 X1 (260h + 0)       ; 12bit ; \ counted in video clock units,
+; 12 - 23 X2 (260h + 320 * 8) ; 12bit ; / relative to HSYNC
+gp_HorizontalDisplayRange_3168_608 equ 0x06 << gcmd_offset | 0xC60 << 12 | 0x260
+
+; GP1(07h) - Vertical Display range (on Screen)
+; 0  - 9  Y1 (NTSC = 88h - (240 / 2), (PAL = A3h - (288 / 2))  ; \ scanline numbers on screen,
+; 10 - 19 Y2 (NTSC = 88h + (240 / 2), (PAL = A3h + (288 / 2))  ; / relative to VSYNC
+; 20 - 23 Not used (zero)
+gp_VerticalDisplayRange_264_24 equ 0x07 << gcmd_offset | 0x042 << 12 | 0x018
+
+; GPU Draw Comamnd Format: [7:8] Command (8-bit), [0:6] Parameter (24-bit)
+
+;GP0(E1h) - Draw Mode setting (aka "Texpage")
+; 0 - 3   Texture page X Base       (N * 64)  (ie. in 64-halfword steps)                       ; GPUSTAT.0-3
+; 4       Texture page Y Base 1     (N * 256) (ie. 0, 256, 512 or 768)                         ; GPUSTAT.4
+; 5 - 6   Semi-transparency         (0 = B / 2 + F / 2, 1 = B + F, 2 = B - F, 3 = B + F / 4)   ; GPUSTAT.5-6
+; 7 - 8   Texture page colors       (0 = 4 bit, 1 = 8bit, 2 = 15bit, 3 = Reserved)             ; GPUSTAT.7-8
+; 9       Dither 24bit to 15bit     (0=Off / strip LSBs, 1 = Dither Enabled)                   ; GPUSTAT.9
+; 10      Drawing to display area   (0=Prohibited, 1=Allowed)                                  ; GPUSTAT.10
+; 11      Texture page Y Base 2     (N * 512) (only for 2 MB VRAM)                             ; GPUSTAT.15
+; 12      Textured Rectangle X-Flip (BIOS does set this bit on power-up...?)
+; 13      Textured Rectangle Y-Flip (BIOS does set it equal to GPUSTAT.13...?)
+; 14 - 23 Not used (should be 0)
+; 24 - 31 Command  (E1h)
+@gp_ModeSetting_DrawAllowed equ 10
+gp_ModeSetting_DipArea equ 0xE1 << gcmd_offset | 0x1 << @gp_ModeSetting_DrawAllowed
+
+; GP0(E3h) - Set Drawing Area top left (X1,Y1)
+; GP0(E4h) - Set Drawing Area bottom right (X2,Y2)
+; Sets the drawing area corners. The Render commands GP0(20h..7Fh) are automatically clipping any pixels that are outside of this region.
+; 0  - 9   X-coordinate (0..1023)
+; 10 - 18  Y-coordinate (0..511)   ; \ on v0 GPU (max 1 MB VRAM)
+; 19 - 23  Not used (zero)         ; /
+; 10 - 19  Y-coordinate (0..1023)  ; \ on v2 GPU (max 2 MB VRAM)
+; 20 - 23  Not used (zero)         ; /
+; 24 - 31  Command  (Exh)
+gp_SetArea_XCoord equ 0
+gp_SetArea_YCoord equ 10
+gp_SetArea_TopLeft     equ 0xE3 << gcmd_offset
+gp_SetArea_BottomRight equ 0xE4 << gcmd_offset
+
+; GP0(E5h) - Set Drawing Offset (X,Y)
+; 0-9    X-coordinate (0..1023)
+; 10-18  Y-coordinate (0..511)   ;\on v0 GPU (max 1 MB VRAM)
+; 19-23  Not used (zero)         ;/
+; 10-19  Y-coordinate (0..1023)  ;\on v2 GPU (max 2 MB VRAM)
+; 20-23  Not used (zero)         ;/
+; 24-31  Command  (Exh)
+gp_SetOffset_XCoord equ 0
+gp_SetOffset_YCoord equ 10
+gp_SetOffset equ 0xE5 << gcmd_offset
+
+; GPU Memory Transfer Commands
+
+; GP0(02h) Fill Vram
+; GP0(02h) - Fill Rectangle in VRAM
+; 1st  Color+Command     (CcBbGgRrh)  ;24bit RGB value (see note)
+; 2nd  Top Left Corner   (YyyyXxxxh)  ;Xpos counted in halfwords, steps of 10h
+; 3rd  Width+Height      (YsizXsizh)  ;Xsiz counted in halfwords, steps of 10h
+ ; Fills the area in the frame buffer with the value in RGB. Horizontally the filling is done in 16-pixel (32-bytes) units 
+ ; (see below masking/rounding).
+ ; The "Color" parameter is a 24bit RGB value, however, the actual fill data is 16bit: 
+ ; The hardware automatically converts the 24bit RGB value to 15bit RGB (with bit15=0).
+ ; Fill is NOT affected by the Mask settings (acts as if Mask.Bit0,1 are both zero).
+gvm_FillRect equ 0x02 << gcmd_offset
+
+.macro gp_push_pak, port, packet, reg_scratch
+	load_imm   reg_scratch, packet
+	store_word reg_scratch, port 
+.endmacro
+.macro gcmd_push, port, cmd, reg_scratch
+	load_imm   reg_scratch, cmd
+	store_word reg_scratch, port 
+.endmacro
+
+Color_PS_GoldenPoppy equ 0xF3C300
+
+main:
+	reg_io_offset equ rtmp_0 :: load_uimm rtmp_0, IO_BASE_ADDR
+; Setup Display Control
+; 1. GP1: Reset GPU
+	load_imm   rtmp_1, 0x00000000                 ; 00 = Reset GPU
+	store_word rtmp_1, gpio_port0(reg_io_offset) ; Writing to GP1
+; 2. GP1: Display Enable
+	load_imm   rtmp_1, gp_DisplayEnabled
+	store_word rtmp_1, gpio_port0(reg_io_offset)  ; Write to GP1
+; 3. GP1: Dispaly Mode (320x240, 15-bit, NTSC)
+	load_imm   rtmp_1, gp_DisplayMode_320x240_15bit_NTSC
+	store_word rtmp_1, gpio_port0(reg_io_offset) ; Write to GP1
+; 4. GP1: Horizontal Range
+	load_imm   rtmp_1, gp_HorizontalDisplayRange_3168_608
+	store_word rtmp_1, gpio_port0(reg_io_offset)
+; 5. GP1: Vertical Range
+	load_imm   rtmp_1, gp_VerticalDisplayRange_264_24
+	store_word rtmp_1, gpio_port0(reg_io_offset)
+; Setup VRAM Access
+; 1. GP0: Drawing mode settings
+	load_imm   rtmp_1, gp_ModeSetting_DipArea
+	store_word rtmp_1, gpio_port0(reg_io_offset)
+; 2. GP0: Drawing area Top-Left
+	load_imm   rtmp_1, gp_SetArea_TopLeft | 0x0
+	store_word rtmp_1, gpio_port0(reg_io_offset)
+; 3. GP0: Drawing area Bottom-Right
+	load_imm   rtmp_1, gp_SetArea_BottomRight | 239 << gp_SetArea_XCoord | 319 << gp_SetArea_XCoord
+	store_word rtmp_1, gpio_port0(reg_io_offset)
+; 4. GP0: Drawing area offset X & Y
+	load_imm   rtmp_1, gp_SetOffset | 0 << gp_SetOffset_YCoord | 0 << gp_SetOffset_XCoord
+	store_word rtmp_1, gpio_port0(reg_io_offset)
+; TODO: Clear the screen
+; 1. GP0: Fill rectangle on display area
+; TODO: Draw a flat-shaded triangle
+; 1. GP0: Send packets to GP0 to draw a triangle
+
+idle:
+	jump idle :: nop
+
+.close
diff --git a/code/warmup/exercise_1.s b/code/warmup/exercise_1.s
index 5882afd..8c3e261 100644
--- a/code/warmup/exercise_1.s
+++ b/code/warmup/exercise_1.s
@@ -1,5 +1,5 @@
 .psx
-.create "exercise_1.bin", 0x80010000
+.create "./build/exercise_1.bin", 0x80010000
 
 ; Entry Point of Code
 .org 0x80010000
diff --git a/code/warmup/exercise_2.s b/code/warmup/exercise_2.s
index 25361d3..b653310 100644
--- a/code/warmup/exercise_2.s
+++ b/code/warmup/exercise_2.s
@@ -1,5 +1,5 @@
 .psx
-.create "exercise_2.bin", 0x80010000
+.create "./build/exercise_2.bin", 0x80010000
 
 ; Entry Point of Code
 .org 0x80010000
diff --git a/code/warmup/exercise_3.s b/code/warmup/exercise_3.s
index 8232472..5498226 100644
--- a/code/warmup/exercise_3.s
+++ b/code/warmup/exercise_3.s
@@ -1,5 +1,5 @@
 .psx
-.create "exercise_3.bin", 0x80010000
+.create "./build/exercise_3.bin", 0x80010000
 
 ; Entry Point of Code
 .org 0x80010000
diff --git a/docs/Sony-PlayStation-Hardware.pdf b/docs/Sony-PlayStation-Hardware.pdf
new file mode 100644
index 0000000..f11f94c
Binary files /dev/null and b/docs/Sony-PlayStation-Hardware.pdf differ
diff --git a/example.asm b/example.asm
deleted file mode 100644
index fe1933c..0000000
--- a/example.asm
+++ /dev/null
@@ -1,17 +0,0 @@
-; Entry Point of Code
-.org 0x80010000
-
-; Constant declaration
-BASE_ADDR equ 0x0000
-
-Main:
-	li $t0, 0xA000 ; $t0 = 0xA000
-	li $t1, 0xA0FF ; $t1 = 0xA0FF
-	li $t2, 0x11   ; $t2 = 0x11
-
-Loop:
-	sb   $t2, BASE_ADDR($t0) ; $Store byte at 0x0000 + t0
-	addi $t0, $t0, 1         ; ++ t0
-	blt  $t0, $t1, Loop      ; while (t0 < t1) keep looping
-
-.close
diff --git a/fillmem.bin b/fillmem.bin
new file mode 100644
index 0000000..86a9f22
Binary files /dev/null and b/fillmem.bin differ
diff --git a/scripts/build.ps1 b/scripts/build.ps1
index f603d12..779370c 100644
--- a/scripts/build.ps1
+++ b/scripts/build.ps1
@@ -21,10 +21,10 @@ function build-program { param(
 	$bin         = join-path $path_build  "$unit.bin"
 	$exe         = join-path $path_build  "$unit.exe"
 
-	push-location $path_build
+	push-location $root
 	write-host "Assembling: $src`n"
 	& $armips $src
-
+	
 	write-host 'Generating executable..'
 	& lua $bin2exe_lua $bin $exe
 	# & py $bin2exe_py $bin $exe
@@ -36,4 +36,5 @@ function build-program { param(
 # build-program 'warmup' 'exercise_1'
 # build-program 'warmup' 'exercise_2'
 # build-program 'warmup' 'exercise_3'
-build-program 'factorial' 'factorial' 
\ No newline at end of file
+# build-program 'factorial' 'factorial' 
+build-program 'graphics_system' 'hellogpu'