Commit: 15d3766712528225397183e84aa5cb144fd65590
Author: Vi Grey
Date: 2018-11-29 07:18 UTC
Summary: Initial Commit

 .gitignore               |    2 +
 LICENSE                  |   24 +
 Makefile                 |   58 ++
 README.md                |   80 +++
 SHA256SUMS.txt           |    5 +
 src/brainfu.asm          | 2633 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/graphics/tileset.chr |  Bin 0 -> 8186 bytes
 7 files changed, 2802 insertions(+)


diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c745919
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+bin
+build
diff --git a/LICENSE b/LICENSE
new file mode 100755
index 0000000..d1a09f3
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,24 @@
+Copyright (C) 2018, Vi Grey
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
diff --git a/Makefile b/Makefile
new file mode 100755
index 0000000..9b2f94a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,58 @@
+# Copyright (C) 2018, Vi Grey
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+
+PKG_NAME := brainfu
+CURRENTDIR := $(dir $(realpath $(firstword $(MAKEFILE_LIST))))
+DIRNAME := $(shell basename $(CURRENTDIR))
+
+all:
+	mkdir -p $(CURRENTDIR)bin; \
+  rm -rf -- build/*; \
+	mkdir -p $(CURRENTDIR)build/$(PKG_NAME)/src; \
+  cd $(CURRENTDIR)src; \
+  asm $(PKG_NAME).asm ../bin/$(PKG_NAME).nes; \
+  cd ..; \
+  rm -f -- bin/new.nes; \
+  rm -f -- bin/new.zip; \
+  cp -r src build/$(PKG_NAME); \
+  cp LICENSE build/$(PKG_NAME); \
+  cp Makefile build/$(PKG_NAME); \
+  cp README.md build/$(PKG_NAME); \
+  cp SHA256SUMS.txt build/$(PKG_NAME); \
+  cd build; \
+  zip -r $(PKG_NAME).zip $(PKG_NAME); \
+  cd ..; \
+  ZIPSIZE=$$(stat -L -c %s build/$(PKG_NAME).zip); \
+  head -c $$((24592 - $$ZIPSIZE)) bin/$(PKG_NAME).nes > build/new.nes; \
+  cat build/$(PKG_NAME).zip >> build/new.nes; \
+  zip -F build/new.nes --out build/new.zip; \
+  head -c 40976 bin/$(PKG_NAME).nes | tail -c 16384 >> build/new.zip; \
+  mv build/new.zip bin/$(PKG_NAME).nes; \
+
+
+
+clean:
+	rm -rf -- $(CURRENTDIR)bin; \
+	rm -rf -- $(CURRENTDIR)build; \
diff --git a/README.md b/README.md
new file mode 100755
index 0000000..1cf255f
--- /dev/null
+++ b/README.md
@@ -0,0 +1,80 @@
+# Brain Fu Interpreter NES Cartridge
+
+A brainfu* interpreter written for NES cartridge to be played on real NES hardware.
+
+**_Brain Fu Interpreter NES Cartridge was created by Vi Grey and is licensed under the BSD 2-Clause License._**
+
+### Description:
+This NES game is an interpreter for the brainfu* programming language, a esoteric Turing Complete programming language that uses only 8 instructions.  The standard NES controller is used to create and run programs using only the power of the NES hardware CPU.
+
+### Platforms:
+- GNU/Linux
+
+### Build Dependencies:
+- asm6 _(You'll probably have to build asm6 from source.  Make sure the asm6 binary is named **asm** and that the binary is executable and accessible in your PATH. The source code can be found at **http://3dscapture.com/NES/asm6.zip**)_
+- zip
+- gmake
+
+### Build NES ROM:
+From a terminal, go to the the main directory of this project (the directory this README.md file exists in), you can then build the NES ROM with the following command.
+
+    $ make
+
+The resulting NES ROM will be located at **bin/brainfu.nes**
+
+### Cleaning Build Environment:
+If you used `make` to build the NES ROM, you can run the following command to clean up the build environment.
+
+    $ make clean
+
+### Controls:
+- A + Up: `+`
+- A + Down: `-`
+- A + Left: `<`
+- A + Right: `>`
+- B + Up: `.`
+- B + Down: `,`
+- B + Left: `[`
+- B + Right: `]`
+- Start: `Run`
+- Select: `Backspace`
+
+### Specifications:
+- 1024 Byte Instruction Buffer _($0200-$05FF)_
+- 512 Byte Memory Tape _($0600-$07FF)_
+- 28 x 19 Print Screen Size _(7 bit ASCII Characters)_
+
+### Extras:
+- #### Unzipping the ROM:
+
+  The compiled NES ROM file at **bin/brainfu.nes** will also be a functioning ZIP file that contains its own source code when unzipped.
+
+- #### Identical EPROM data:
+
+  This NES game is created in such a way that both the PRG and CHR EPROMs for an NROM-256 board contain the exact same data.  This means the PRG and CHR EPROMs can be swapped and the game will still function exactly the same.
+
+### License:
+    Copyright (C) 2018, Vi Grey
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+        1. Redistributions of source code must retain the above copyright
+           notice, this list of conditions and the following disclaimer.
+        2. Redistributions in binary form must reproduce the above copyright
+           notice, this list of conditions and the following disclaimer in the
+           documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS \`\`AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
diff --git a/SHA256SUMS.txt b/SHA256SUMS.txt
new file mode 100755
index 0000000..5e55a05
--- /dev/null
+++ b/SHA256SUMS.txt
@@ -0,0 +1,5 @@
+887e1b994f19ba3c4f159ea1e904d8e4785ef63a4fd4a4702956b85e61421c13  LICENSE
+45920c73c4cdaa5531582ed5826441cd6f64c3a0a680d96db89042af51a5e47a  Makefile
+bc1f35c967301a2fd3c5c393a98f4d8152d008e290783bb4df8361690cc85f94  README.md
+a5c8607d136a8804a73a850d63754bc967720400e9ae095a9d1c43fbd753a4e3  src/brainfu.asm
+8f7a7af15a94e4bc6ffea8e63300e1ec2dc383cc537af46e78ecf391ccf41be5  src/graphics/tileset.chr
diff --git a/src/brainfu.asm b/src/brainfu.asm
new file mode 100755
index 0000000..52dc3e9
--- /dev/null
+++ b/src/brainfu.asm
@@ -0,0 +1,2633 @@
+;; Copyright (C) 2018, Vi Grey
+;; All rights reserved.
+;;
+;; Redistribution and use in source and binary forms, with or without
+;; modification, are permitted provided that the following conditions
+;; are met:
+;;
+;; 1. Redistributions of source code must retain the above copyright
+;;    notice, this list of conditions and the following disclaimer.
+;; 2. Redistributions in binary form must reproduce the above copyright
+;;    notice, this list of conditions and the following disclaimer in the
+;;    documentation and/or other materials provided with the distribution.
+;;
+;; THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+;; ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+;; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+;; ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+;; FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+;; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+;; OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+;; HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+;; LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+;; OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+;; SUCH DAMAGE.
+
+
+
+;; NOTE - Pardon how few comments there are in this 6502 assembly code.
+;; I was a bit rushed to get the original batch of cartridges done in
+;; time for DEFCON and haven't had the motivation to go in and add
+;; comments, even when updating this code.
+
+
+;; INES header setup
+  .db "NES", $1A
+  .db $02 ; $01 will also work for this particular rom
+  .db $01
+  .db $00
+  .db $00
+  .db 0, 0, 0, 0, 0, 0, 0, 0 ; pad header to 16 bytes
+
+;; Initialize Variables
+  enum $00
+powered dsb 4
+edition dsb 1
+background dsb 1
+foreground dsb 1
+reset dsb 1
+addr dsb 2
+cursorframe dsb 1
+cursoraddr dsb 2
+textaddr dsb 2
+printaddr dsb 2
+fps dsb 1
+drawAllowed dsb 1
+tmp dsb 1
+screen dsb 1
+option dsb 1
+slide dsb 1
+input dsb 1
+inputpointer dsb 1
+code dsb 1
+controller1 dsb 1
+controller2 dsb 1
+controller1LastFrame dsb 1
+frames dsb 1
+del dsb 1
+
+twoCt dsb 1
+twoSt dsb 1
+width dsb 1
+widthOffset dsb 1
+height dsb 1
+framelocation dsb 2
+drawAddr dsb 2
+
+instAddr dsb 2
+instAddrOffset dsb 2
+instScreenAddr dsb 2
+row dsb 1
+rowadjusted dsb 1
+col dsb 1
+memoffset dsb 2
+square dsb 2
+interpret dsb 1
+err dsb 1
+
+  ende
+
+BUTTON_A         = 1 << 7
+BUTTON_B         = 1 << 6
+BUTTON_SELECT    = 1 << 5
+BUTTON_START     = 1 << 4
+BUTTON_UP        = 1 << 3
+BUTTON_DOWN      = 1 << 2
+BUTTON_LEFT      = 1 << 1
+BUTTON_RIGHT     = 1 << 0
+BACKGROUND       = $0F
+FOREGROUND       = $10
+EDITION          = $03
+SLIDEQTY         = $0B
+
+  .base $8000
+
+;; Run upon power on or reset
+RESET:
+  sei          ; disable IRQs
+  cld          ; disable decimal mode, meant to make decimal arithmetic "easier"
+  ldx #$40
+  stx $4017    ; disable APU frame IRQ
+  ldx #$FF
+  txs          ; Set up stack
+  inx          ; X overflows back to 0
+  jsr Blank
+  stx $4010    ; disable DMC IRQs
+  ldx #$00 ;reset x back to 0
+  ldy #$00 ;reset y back to 0
+
+;; First vblank wait to make sure PPU is ready
+vwait1:
+  lda $2002 ; wait
+  bpl vwait1
+
+;; Second vblank wait, PPU is ready after this
+;; Region detection code inspired by Damian Yerrick's code,
+;; although his code has better documentation as to why it works
+vwait2:
+  inx
+  bne DoNotIncY
+  iny
+DoNotIncY:
+  lda $2002 ; wait
+  bpl vwait2
+  tya
+  cmp #$10
+  bcc DoNotDiv2
+  lsr
+DoNotDiv2:
+  clc
+  adc #<-$09
+  ldx #50
+  cmp #$00
+  bne Not60fps
+  ldx #60
+Not60fps:
+  stx fps
+
+;; Initialize memory and APU
+Initialize:
+  ldx #$00
+InitializeLoop:
+  ; reset values of $0000 - $01FF and $0300 - $07FF back to 0
+  lda #$00
+  cpx #fps
+  beq InitializeSkipDone
+  cpx #powered
+  beq InitializeSkipDone
+  cpx #(powered + 1)
+  beq InitializeSkipDone
+  cpx #(powered + 2)
+  beq InitializeSkipDone
+  cpx #(powered + 3)
+  beq InitializeSkipDone
+  cpx #background
+  beq InitializeSkipDone
+  cpx #foreground
+  beq InitializeSkipDone
+  sta $0000, x
+InitializeSkipDone:
+  sta $0100, x
+  sta $0200, x
+  sta $0300, x
+  sta $0400, x
+  sta $0500, x
+  sta $0600, x
+  sta $0700, x
+  inx
+  bne InitializeLoop ;repeat until x rolls back to 0
+  ldx #$FF
+  stx controller1
+InitializeDone:
+  jsr ResetCheck
+  ldx #$DC
+  stx powered
+  ldx #$26
+  stx (powered + 1)
+  ldx #$65
+  stx (powered + 2)
+  ldx #$02
+  stx (powered + 3)
+  lda #$00 ;reset A value
+  ldx #$00 ;reset X value
+  ldy #$00 ;reset Y value
+
+;; Load initial palette data and background
+  ldx background
+  cpx #$00
+  bne ForegroundBackgroundSame
+  ldx #BACKGROUND
+  stx background
+  ldy #FOREGROUND
+  sty foreground
+ForegroundBackgroundSame:  
+  ldx background
+  ldy foreground
+  jsr SetPalette
+
+  lda #EDITION
+  sta edition
+
+  jsr DrawTitle
+
+
+;; Loop forever
+Forever:
+  jmp Forever
+
+;; Game NMI loop
+NMI:
+  inc frames
+  ldx drawAllowed
+  cpx #$01
+  bne DrawFinished ; continue if drawAllowed is 1
+  lda $2002 ; wait
+  lda #$00
+  sta $2005
+  sta $2005
+  jsr EnableNMI
+  jsr Draw
+  ldx interpret
+  cpx #$00
+  beq DrawFinished
+  ldx #$00
+  stx err
+  jsr DisableNMI
+  jsr Interpret
+DrawFinished:
+  jsr Update
+  lda frames
+  clc
+  asl
+  cmp fps
+  bne NMIDone
+  jsr BlinkCursor
+  jsr ResetScroll
+  ldx #$00
+  stx frames
+NMIDone:
+  rti ;return from interrupt
+
+;; Check if Reset was hit
+ResetCheck:
+  lda #$01
+  sta reset
+  lda powered
+  cmp #$DC
+  bne NotPowered
+  lda (powered + 1)
+  cmp #$26
+  bne NotPowered
+  lda (powered + 2)
+  cmp #$65
+  bne NotPowered
+  lda (powered + 3)
+  cmp #$02
+  beq ResetCheckDone
+NotPowered:
+  lda #$00
+  sta reset
+  lda #FOREGROUND
+  sta foreground
+  lda #BACKGROUND
+  sta background
+ResetCheckDone:
+  rts
+
+;; Tell both controllers to latch buttons
+LatchController:
+  lda #$01
+  sta $4016
+  lda #$00
+  sta $4016 ; Sending 01 then 00 to $4016 strobes the controllers for input values
+  rts
+
+;;Get button presses from both controllers
+PollController:
+  ldx controller1
+  stx controller1LastFrame
+  ldx #$08 ; 8 buttons total
+PollControllerLoop:
+  lda $4016 ; player 1
+PollController1:
+  lsr A ; shift right
+  rol controller1 ; rotate left button vector in controller1 mem location
+  lda $4017 ; player 2
+PollControllerL2:
+  lsr A
+  rol controller2
+PollControllerEnd:
+  dex
+  bne PollControllerLoop ; repeat loop if x != 0
+  lda controller1
+  cmp #$00
+  bne Controller1Press ; Continue if nothing was pressed on controller 1
+  lda controller2
+  sta controller1 ; Put controller 2's button input into controller1
+Controller1Press:
+  rts
+
+CheckUp:
+  lda controller1
+  cmp #(BUTTON_UP)
+  beq CheckUpProcessStart
+  jsr CheckBlank
+  rts
+CheckUpProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckUpDone
+  cmp #(BUTTON_UP)
+  bne CheckUpContinue
+  rts
+CheckUpContinue:
+  ldx screen
+  cpx #$02
+  bne CheckUpNot2
+  jsr FlipBit
+  jmp CheckUpNotFF
+CheckUpNot2:
+  cpx #$FF
+  bne CheckUpNotFF
+  ldx option
+  cpx #$00
+  beq CheckUpNotFF
+  dec option
+  jsr DrawTitleCursor
+CheckUpNotFF:
+  ldx code
+  cpx #$01
+  beq CheckUpIncCode
+  ldx #$01
+  stx code
+  jmp CheckUpDone
+CheckUpIncCode:
+  inc code
+CheckUpDone:
+  rts
+
+CheckDown:
+  lda controller1
+  cmp #(BUTTON_DOWN)
+  beq CheckDownProcessStart
+  jsr CheckBlank
+  rts
+CheckDownProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckDownDone
+  cmp #(BUTTON_DOWN)
+  bne CheckDownContinue
+  rts
+CheckDownContinue:
+  ldx screen
+  cpx #$02
+  bne CheckDownNot2
+  jsr FlipBit
+  jmp CheckDownNotFF
+CheckDownNot2:
+  cpx #$FF
+  bne CheckDownNotFF
+  ldx option
+  cpx #$02
+  beq CheckDownNotFF
+  inc option
+  jsr DrawTitleCursor
+CheckDownNotFF:
+  ldx code
+  cpx #$02
+  beq CheckDownIncCode
+  cpx #$03
+  bne CheckDownDone
+CheckDownIncCode:
+  inc code
+  rts
+CheckDownDone:
+  ldx #$00
+  stx code
+  rts
+
+CheckLeft:
+  lda controller1
+  cmp #(BUTTON_LEFT)
+  beq CheckLeftProcessStart
+  jsr CheckBlank
+  rts
+CheckLeftProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckLeftDone
+  cmp #(BUTTON_LEFT)
+  bne CheckLeftContinue
+  rts
+CheckLeftContinue:
+  ldx screen
+  cpx #$02
+  bne CheckLeftNot2
+  ldx #$00
+  jsr MoveBit
+CheckLeftNot2:
+  ldx code
+  cpx #$04
+  beq CheckLeftIncCode
+  cpx #$06
+  bne CheckLeftDone
+CheckLeftIncCode:
+  inc code
+  rts
+CheckLeftDone:
+  ldx #$00
+  stx code
+  rts
+
+CheckRight:
+  lda controller1
+  cmp #(BUTTON_RIGHT)
+  beq CheckRightProcessStart
+  jsr CheckBlank
+  rts
+CheckRightProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckRightDone
+  cmp #(BUTTON_RIGHT)
+  bne CheckRightContinue
+  rts
+CheckRightContinue:
+  ldx screen
+  cpx #$02
+  bne CheckRightNot2
+  ldx #$01
+  jsr MoveBit
+CheckRightNot2:
+  ldx code
+  cpx #$05
+  beq CheckRightIncCode
+  cpx #$07
+  bne CheckRightDone
+CheckRightIncCode:
+  inc code
+  rts
+CheckRightDone:
+  ldx #$00
+  stx code
+  rts
+
+CheckB:
+  lda controller1
+  cmp #(BUTTON_B)
+  beq CheckBProcessStart
+  jsr CheckBlank
+  rts
+CheckBProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckBDone
+  cmp #(BUTTON_B)
+  bne CheckBContinue
+  rts
+CheckBContinue:
+  ldx code
+  cpx #$08
+  bne CheckBNotCode
+CheckBIncCode:
+  inc code
+  rts
+CheckBNotCode:
+  ldx screen
+  cpx #$FD
+  bne CheckBNotScreenFD
+  jsr DrawTitle
+  rts
+CheckBNotScreenFD:
+  cpx #$FE
+  bne CheckBDone
+  ldx slide
+  cpx #$00 
+  beq CheckBTutorialFirstSlide
+  dec slide
+  jsr DrawTutorialSlide
+  rts
+CheckBTutorialFirstSlide:
+  jsr DrawTitle
+CheckBDone:
+  ldx #$00
+  stx code
+  rts
+
+CheckA:
+  lda controller1
+  cmp #(BUTTON_A)
+  beq CheckAProcessStart
+  jsr CheckBlank
+  rts
+CheckAProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckADone
+  cmp #(BUTTON_A)
+  bne CheckAContinue
+  rts
+CheckAContinue:
+  cmp #$00
+  bne CheckADone
+  ldx code
+  cpx #$09
+  bne CheckANotCode
+  jsr SwitchColors
+  jmp CheckADone
+CheckANotCode
+  ldx screen
+  cpx #$FF
+  bne CheckANotScreenFF
+  ldx option
+  cpx #$00
+  bne CheckANotOption0
+  jsr DrawInterpreter
+  rts
+CheckANotOption0:
+  cpx #$01
+  bne CheckANotOption1
+  ldx #$00
+  stx slide
+  jsr DrawTutorialSlide
+  rts
+CheckANotOption1:
+  cpx #$02
+  bne CheckADone
+  jsr DrawAbout
+  rts
+CheckANotScreenFF:
+  cpx #$FE
+  bne CheckADone
+  ldx slide
+  cpx #SLIDEQTY 
+  beq CheckATutorialLastSlide
+  inc slide
+  jsr DrawTutorialSlide
+  rts
+CheckATutorialLastSlide:
+  jsr DrawTitle
+CheckADone:
+  ldx #$00
+  stx code
+  rts
+
+CheckAUp:
+  lda controller1
+  cmp #(BUTTON_A + BUTTON_UP)
+  beq CheckAUpProcessStart
+  jmp CheckAUpDone
+CheckAUpProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckAUpDone
+  cmp #(BUTTON_A + BUTTON_UP)
+  beq CheckAUpDone
+  lda #$2B ; +
+  ldx #$00
+  jsr WriteInstruction
+  jsr Inc16InstAddrOffset
+CheckAUpDone:
+  rts
+
+CheckADown:
+  lda controller1
+  cmp #(BUTTON_A + BUTTON_DOWN)
+  beq CheckADownProcessStart
+  jmp CheckADownDone
+CheckADownProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckADownDone
+  cmp #(BUTTON_A + BUTTON_DOWN)
+  beq CheckADownDone
+  lda #$2D ; -
+  ldx #$00
+  jsr WriteInstruction
+  jsr Inc16InstAddrOffset
+CheckADownDone:
+  rts
+
+CheckALeft:
+  lda controller1
+  cmp #(BUTTON_A + BUTTON_LEFT)
+  beq CheckALeftProcessStart
+  jmp CheckALeftDone
+CheckALeftProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckALeftDone
+  cmp #(BUTTON_A + BUTTON_LEFT)
+  beq CheckALeftDone
+  lda #$3C ; <
+  ldx #$00
+  jsr WriteInstruction
+  jsr Inc16InstAddrOffset
+CheckALeftDone:
+  rts
+
+CheckARight:
+  lda controller1
+  cmp #(BUTTON_A + BUTTON_RIGHT)
+  beq CheckARightProcessStart
+  jmp CheckARightDone
+CheckARightProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckARightDone
+  cmp #(BUTTON_A + BUTTON_RIGHT)
+  beq CheckARightDone
+  lda #$3E ; >
+  ldx #$00
+  jsr WriteInstruction
+  jsr Inc16InstAddrOffset
+CheckARightDone:
+  rts
+
+CheckBUp:
+  lda controller1
+  cmp #(BUTTON_B + BUTTON_UP)
+  beq CheckBUpProcessStart
+  jmp CheckBUpDone
+CheckBUpProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckBUpDone
+  cmp #(BUTTON_B + BUTTON_UP)
+  beq CheckBUpDone
+  lda #$2E ; .
+  ldx #$00
+  jsr WriteInstruction
+  jsr Inc16InstAddrOffset
+CheckBUpDone:
+  rts
+
+CheckBDown:
+  lda controller1
+  cmp #(BUTTON_B + BUTTON_DOWN)
+  beq CheckBDownProcessStart
+  jmp CheckBDownDone
+CheckBDownProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckBDownDone
+  cmp #(BUTTON_B + BUTTON_DOWN)
+  beq CheckBDownDone
+  lda #$2C ; ,
+  ldx #$00
+  jsr WriteInstruction
+  jsr Inc16InstAddrOffset
+CheckBDownDone:
+  rts
+
+CheckBLeft:
+  lda controller1
+  cmp #(BUTTON_B + BUTTON_LEFT)
+  beq CheckBLeftProcessStart
+  jmp CheckBLeftDone
+CheckBLeftProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckBLeftDone
+  cmp #(BUTTON_B + BUTTON_LEFT)
+  beq CheckBLeftDone
+  lda #$5B ; [
+  ldx #$00
+  jsr WriteInstruction
+  jsr Inc16InstAddrOffset
+CheckBLeftDone:
+  rts
+
+CheckBRight:
+  lda controller1
+  cmp #(BUTTON_B + BUTTON_RIGHT)
+  beq CheckBRightProcessStart
+  jmp CheckBRightDone
+CheckBRightProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckBRightDone
+  cmp #(BUTTON_B + BUTTON_RIGHT)
+  beq CheckBRightDone
+  lda #$5D ; ]
+  ldx #$00
+  jsr WriteInstruction
+  jsr Inc16InstAddrOffset
+CheckBRightDone:
+  rts
+
+CheckStart:
+  lda controller1
+  cmp #(BUTTON_START)
+  beq CheckStartProcessStart
+  jmp CheckStartDone
+CheckStartProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  bne CheckStartProcessContinue
+  jmp CheckStartDone
+CheckStartProcessContinue:
+  cmp #$00
+  beq CheckStartProcessContinue2
+  jmp CheckStartDone
+CheckStartProcessContinue2:
+  ldx screen
+  cpx #$02
+  bne CheckStartNot2
+  ldx #$00
+  stx screen
+  lda input
+  ldy #$00
+  sta (memoffset), Y
+  jsr Blank
+  lda #<(ProcessingText)
+  sta addr
+  lda #>(ProcessingText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(InstructionBlank)
+  sta addr
+  lda #>(InstructionBlank)
+  sta (addr + 1)
+  jsr NamDecompress
+  jsr ResetScroll
+  ldx #$01
+  stx screen
+  ldx #$02
+  stx interpret
+  jmp CheckStartDone
+CheckStartNot2:
+  cpx #$01
+  bne CheckStartNot1
+  ldx #$00
+  stx screen
+  jsr Blank
+  jsr ClearInstructions
+  lda #<(InstructionData)
+  sta addr
+  lda #>(InstructionData)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(ReadyText)
+  sta addr
+  lda #>(ReadyText)
+  sta (addr + 1)
+  jsr NamDecompress
+  jsr ResetScroll
+  jmp CheckStartDone
+CheckStartNot1:
+  cpx #$00
+  bne CheckStartNot0
+  jsr Blank
+  lda #<(ScreenBlankData)
+  sta addr
+  lda #>(ScreenBlankData)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(ProcessingText)
+  sta addr
+  lda #>(ProcessingText)
+  sta (addr + 1)
+  jsr NamDecompress
+  jsr ResetScroll
+  ldx #$01
+  stx interpret
+  stx screen
+CheckStartNot0:
+  cpx #$FF
+  bne CheckStartNotFF
+  ldx option
+  cpx #$00
+  bne CheckStartNotOption0
+  jsr DrawInterpreter
+  rts
+CheckStartNotFF:
+  cpx #$FD
+  bne CheckStartNotFD
+  jsr DrawTitle
+  rts
+CheckStartNotFD:
+  cpx #$FE
+  bne CheckStartDone:
+  jsr DrawTitle
+  rts
+CheckStartNotOption0:
+  cpx #$01
+  bne CheckStartNotOption1
+  ldx #$00
+  stx slide
+  jsr DrawTutorialSlide
+  rts
+CheckStartNotOption1:
+  cpx #$02
+  bne CheckStartDone
+  jsr DrawAbout
+CheckStartDone:
+  rts
+
+CheckSelect:
+  lda controller1
+  cmp #(BUTTON_SELECT)
+  beq CheckSelectProcessStart
+  ldx #$00
+  stx del
+  rts
+CheckSelectProcessStart:
+  lda controller1LastFrame
+  cmp #$FF
+  beq CheckSelectDone
+  cmp #$00
+  bne CheckSelectLastSelect
+  ldx screen
+  cpx #$FF
+  bne CheckSelectScreenNotFF
+  inc option
+  ldx option
+  cpx #03
+  bne CheckSelectOptionNot2
+  ldx #$00
+  stx option
+CheckSelectOptionNot2
+  jsr DrawTitleCursor
+  jmp CheckSelectDone
+CheckSelectScreenNotFF:
+  cpx #$00
+  bne CheckSelectDone
+  ldx #$01
+  stx del
+  sta frames
+  jmp CheckSelectLastBlank
+CheckSelectLastSelect:
+  ldx screen
+  cpx #$00
+  bne CheckSelectDone
+  cmp #(BUTTON_SELECT)
+  bne CheckSelectDone
+  ldx del
+  cpx #$01
+  bne CheckSelectDone
+  lda frames
+  clc
+  asl
+  cmp fps
+  bne CheckSelectDone
+  ldx #$01
+  stx cursorframe
+  lda fps
+  clc
+  lsr
+  lsr
+  lsr
+  lsr
+  sta tmp
+  lda frames
+  sec
+  sbc tmp
+  sta frames
+CheckSelectLastBlank:
+  lda #$00
+  ldx #$01
+  jsr WriteInstruction
+  jsr Dec16InstAddrOffset
+  ldx #$00
+  stx cursorframe
+  jsr BlinkCursor
+  jsr ResetScroll
+  lda #$00
+  tay ; Subscribe to @SwiftOnSecurity for Corn Facts
+  sta (instAddrOffset), Y
+CheckSelectDone:
+  rts
+
+CheckBlank:
+  ldx screen
+  cpx #$01
+  beq CheckBlankResetCode
+  cpx #$02
+  beq CheckBlankResetCode
+  ldx controller1
+  cpx #$00
+  beq CheckBlankDone
+CheckBlankUp:
+  cpx #(BUTTON_UP)
+  beq CheckBlankDone
+CheckBlankDown:
+  cpx #(BUTTON_DOWN)
+  beq CheckBlankDone
+CheckBlankLeft:
+  cpx #(BUTTON_LEFT)
+  beq CheckBlankDone
+CheckBlankRight:
+  cpx #(BUTTON_RIGHT)
+  beq CheckBlankDone
+CheckBlankB:
+  cpx #(BUTTON_B)
+  beq CheckBlankDone
+CheckBlankA:
+  cpx #(BUTTON_A)
+  beq CheckBlankDone
+CheckBlankResetCode:
+  ldx #$00
+  stx code
+CheckBlankDone:
+  rts
+
+DetermineTutorialSlide:
+  lda slide
+  asl
+  tay ; Subscribe to @SwiftOnSecurity for Corn Facts
+  lda (SlidesList), Y
+  sta addr
+  iny
+  lda (SlidesList), Y
+  sta (addr + 1)
+  jsr NamDecompress
+  rts
+
+
+DrawTitle:
+  jsr Blank
+  lda #<(BlankMap)
+  sta addr
+  lda #>(BlankMap)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #$00
+  sta option
+  lda #<(TitleBoard)
+  sta addr
+  lda #>(TitleBoard)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(TitleOptions)
+  sta addr
+  lda #>(TitleOptions)
+  sta (addr + 1)
+  jsr NamDecompress
+  ldx #$FF
+  stx screen
+  jsr DrawTitleCursor
+  jsr ResetScroll
+  rts
+
+DrawAbout:
+  jsr Blank
+  lda #<(BlankMap)
+  sta addr
+  lda #>(BlankMap)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(AboutInstructionData)
+  sta addr
+  lda #>(AboutInstructionData)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(FrameData)
+  sta addr
+  lda #>(FrameData)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(AboutData)
+  sta addr
+  lda #>(AboutData)
+  sta (addr + 1)
+  jsr NamDecompress
+  ldx #$FD
+  stx screen
+  jsr ResetScroll
+  rts
+
+DrawTutorialSlide:
+  jsr Blank
+  lda #<(BlankMap)
+  sta addr
+  lda #>(BlankMap)
+  sta (addr + 1)
+  jsr NamDecompress
+  ldx slide
+  cpx #$00
+  bne DrawTutorialNotFirstSlide
+  lda #<(TutorialFirstInstructions)
+  sta addr
+  lda #>(TutorialFirstInstructions)
+  sta (addr + 1)
+  jmp DrawTutorialInstructionsDone
+DrawTutorialNotFirstSlide:
+  cpx #SLIDEQTY
+  bne DrawTutorialNotLastSlide
+  lda #<(TutorialLastInstructions)
+  sta addr
+  lda #>(TutorialLastInstructions)
+  sta (addr + 1)
+  jmp DrawTutorialInstructionsDone
+DrawTutorialNotLastSlide:
+  lda #<(TutorialMiddleInstructions)
+  sta addr
+  lda #>(TutorialMiddleInstructions)
+  sta (addr + 1)
+DrawTutorialInstructionsDone:
+  jsr NamDecompress
+  lda #<(FrameData)
+  sta addr
+  lda #>(FrameData)
+  sta (addr + 1)
+  jsr NamDecompress
+
+  jsr DetermineTutorialSlide
+
+  ldx #$FE
+  stx screen
+  jsr ResetScroll
+  rts
+
+
+DrawTitleCursor:
+  lda #<(TitleCursor)
+  sta addr
+  lda #>(TitleCursor)
+  sta (addr + 1)
+  jsr NamDecompress
+  ldx option
+  lda #$22
+  sta addr
+  lda #$C6
+  sta (addr + 1)
+DrawTitleCursorOptionLoop:
+  cpx #$00
+  beq DrawTitleCursorOptionLoopDone:
+  clc
+  lda (addr + 1)
+  adc #$40
+  sta (addr + 1)
+  lda addr
+  adc #$00
+  sta addr
+  dex
+  jmp DrawTitleCursorOptionLoop
+DrawTitleCursorOptionLoopDone:
+  lda $2002
+  lda addr
+  sta $2006
+  lda (addr + 1)
+  sta $2006
+  lda #$D1
+  sta $2007
+DrawTitleCursorDone:
+  jsr ResetScroll
+  rts
+
+DrawInterpreter:
+  jsr Blank
+  jsr InitializeInstAddrOffset
+  lda #<(BlankMap)
+  sta addr
+  lda #>(BlankMap)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(TopData)
+  sta addr
+  lda #>(TopData)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(InstructionData)
+  sta addr
+  lda #>(InstructionData)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(ReadyText)
+  sta addr
+  lda #>(ReadyText)
+  sta (addr + 1)
+  jsr NamDecompress
+  ldx #$00
+  stx screen
+  jsr ResetCursor
+  jsr ResetScroll
+  rts
+
+
+DrawInput:
+  lda $2002
+  lda #$20
+  sta $2006
+  lda #$A9
+  sta $2006
+  ldx #$00
+  ldy input
+DrawInputLoop:
+  tya
+  and #%10000000
+  beq DrawInputLoopZero:
+  lda #$31
+  jmp DrawInputLoopEnd
+DrawInputLoopZero:
+  lda #$30
+DrawInputLoopEnd:
+  cpx inputpointer
+  bne DrawInputLoopNotSelected
+  clc
+  adc #$C0
+DrawInputLoopNotSelected:
+  sta $2007
+  inx
+  tya
+  asl
+  tay ; Subscribe to @SwiftOnSecurity for Corn Facts
+  cpx #$08
+  bne DrawInputLoop
+DrawInputDone:
+  jsr ResetScroll
+  rts
+
+FlipBit:
+  lda #%10000000
+  ldx #$00
+FlipBitLoop:
+  cpx inputpointer
+  beq FlipBitDone
+  inx
+  clc
+  lsr
+  jmp FlipBitLoop
+FlipBitDone:
+  eor input
+  sta input
+  jsr DrawInput
+  rts
+
+MoveBit:
+  cpx #$00
+  bne MoveBitRight
+  ldx inputpointer
+  cpx #$00
+  beq MoveBitDone
+  dec inputpointer
+  jmp MoveBitDraw
+MoveBitRight:
+  ldx inputpointer
+  cpx #$07
+  beq MoveBitDone
+  inc inputpointer
+MoveBitDraw:
+  jsr DrawInput
+MoveBitDone:
+  rts
+
+SwitchColors:
+  ldx background
+  cpx #$0F
+  beq SwitchColorsBlack
+  ldx #$0F
+  stx background
+  ldy #$10
+  sty foreground
+  jsr SetPalette
+  jmp SwitchColorsDone
+SwitchColorsBlack:
+  ldx #$30
+  stx background
+  ldy #$2D
+  sty foreground
+  jsr SetPalette
+SwitchColorsDone:
+  rts
+
+WriteInstruction:
+  cpx #$01
+  beq WriteInstructionContinue
+  ldx (instAddrOffset + 1)
+  cpx #$06
+  bne WriteInstructionContinue
+  ldx instAddrOffset
+  cpx #$00
+  bne WriteInstructionContinue
+  jmp WriteInstructionDone
+WriteInstructionContinue:
+  ldy #$00
+  sta (instAddrOffset), Y
+  ldx $2002 ;read PPU to reset write toggle
+  ldx (cursoraddr + 1)
+  stx $2006
+  ldx cursoraddr
+  stx $2006
+  sta $2007
+  jsr ResetScroll
+WriteInstructionDone:
+  rts
+
+InitializeInstAddrOffset:
+  lda #$00
+  sta instAddrOffset
+  lda #$02
+  sta (instAddrOffset + 1)
+  rts
+
+Inc16InstAddrOffset:
+  ldx (instAddrOffset + 1)
+  cpx #$06
+  bne Inc16InstAddrOffsetContinue
+  ldx instAddrOffset
+  cpx #$00
+  beq Inc16InstAddrOffsetDone
+Inc16InstAddrOffsetContinue:
+  jsr IncColRow
+  lda instAddrOffset
+  clc
+  adc #$01
+  sta instAddrOffset
+  lda (instAddrOffset + 1)
+  adc #$00
+  sta (instAddrOffset + 1)
+Inc16InstAddrOffsetDone:
+  ldx #$00
+  stx cursorframe
+  stx frames
+  jsr BlinkCursor
+  jsr ResetScroll
+  rts
+
+AdjustCursorAddr:
+  lda col
+  clc
+  adc #$C2
+  sta cursoraddr
+  lda rowadjusted
+  asl
+  asl
+  asl
+  asl
+  asl
+  clc
+  adc cursoraddr
+  sta cursoraddr
+  lda #$00
+  adc #$00
+  tax
+  lda rowadjusted
+  lsr
+  lsr
+  lsr
+  clc
+  adc #$20
+  sta (cursoraddr + 1)
+  txa
+  adc (cursoraddr + 1)
+  sta (cursoraddr + 1)
+  rts
+
+IncColRow:
+  inc col
+  ldx col
+  cpx #$1C
+  bne IncColRowDone
+  ldx #$00
+  stx col
+  inc row
+  inc rowadjusted
+  ldx interpret
+  cpx #$01
+  beq IncColRowDone
+  ldx row
+  cpx #$13
+  bcc IncColRowDone
+  ldx #$F7
+  ldy #$01
+  jsr RedrawInstructions:
+  ldx #$12
+  stx rowadjusted
+IncColRowDone:
+  jsr AdjustCursorAddr
+  rts
+
+DecColRow:
+  dec col
+  ldx col
+  cpx #$FF
+  bne DecColRowDone
+  ldx #$1B
+  stx col
+  dec row
+  ldx row
+  stx rowadjusted
+  cpx #$12
+  bcc DecColRowDone
+  ldx #$14
+  ldy #$02
+  jsr RedrawInstructions
+  ldx #$12
+  stx rowadjusted
+DecColRowDone:
+  jsr AdjustCursorAddr
+  rts
+
+RedrawInstructions:
+  jsr Blank
+  stx tmp
+  lda instAddrOffset
+  sec
+  sbc tmp
+  sta instAddr
+  sty tmp
+  lda (instAddrOffset + 1)
+  sbc tmp
+  sta (instAddr + 1)
+  lda #$20
+  sta instScreenAddr
+  lda #$C2
+  sta (instScreenAddr + 1)
+  ldx #$1C
+RedrawInstructionsLoop:
+  lda $2002 ;read PPU to reset write toggle
+  lda instScreenAddr
+  sta $2006
+  lda (instScreenAddr + 1)
+  sta $2006
+RedrawInstructionsRowLoop:
+  lda instAddr 
+  cmp instAddrOffset
+  bne RedrawInstructionsContinue
+  lda (instAddr + 1)
+  cmp (instAddrOffset + 1)
+  beq RedrawInstructionsCleanLine
+RedrawInstructionsContinue:
+  ldy #$00
+  lda (instAddr), Y
+  sta $2007
+  lda instAddr
+  clc
+  adc #$01
+  sta instAddr
+  lda (instAddr + 1)
+  adc #$00
+  sta (instAddr + 1)
+  dex
+  cpx #$00
+  bne RedrawInstructionsRowLoop
+  ldx #$1C
+  lda (instScreenAddr + 1)
+  clc
+  adc #$20
+  sta (instScreenAddr + 1)
+  lda instScreenAddr
+  adc #$00
+  sta instScreenAddr
+  jmp RedrawInstructionsLoop
+RedrawInstructionsCleanLine:
+  lda instScreenAddr
+  cmp #$23
+  beq RedrawInstructionsDone
+  lda $2002
+  lda #$23
+  sta $2006
+  lda #$02
+  sta $2006
+  ldx #$1C
+  lda #$00
+RedrawInstructionsCleanLineLoop:
+  sta $2007
+  dex
+  cpx #$00
+  bne RedrawInstructionsCleanLineLoop
+RedrawInstructionsDone:
+  jsr ResetScroll
+  rts
+
+Dec16InstAddrOffset:
+  ldx (instAddrOffset + 1)
+  cpx #$02
+  bne Dec16InstAddrOffsetContinue
+  ldx instAddrOffset
+  cpx #$00
+  beq Dec16InstAddrOffsetDone
+Dec16InstAddrOffsetContinue:
+  jsr DecColRow
+  lda instAddrOffset
+  sec
+  sbc #$01
+  sta instAddrOffset
+  lda (instAddrOffset + 1)
+  sbc #$00
+  sta (instAddrOffset + 1)
+  lda #$00
+  ldx #$00
+  jsr WriteInstruction
+Dec16InstAddrOffsetDone:
+  rts
+
+ClearMemory:
+  ldx #00
+  txa
+ClearMemoryLoop:
+  sta $0600, x
+  sta $0700, x
+  inx
+  bne ClearMemoryLoop ;repeat until x rolls back to 0
+ClearMemoryDone:
+  rts
+
+ClearInstructions:
+  ldx #00
+  txa
+ClearInstructionsLoop:
+  sta $0200, x
+  sta $0300, x
+  sta $0400, x
+  sta $0500, x
+  inx
+  bne ClearInstructionsLoop ;repeat until x rolls back to 0
+ClearInstructionsDone:
+  rts
+
+Interpret:
+  lda interpret
+  cmp #$02
+  beq InterpretLoop
+  lda #$00
+  sta col
+  sta row
+  sta rowadjusted
+  sta instAddrOffset
+  sta memoffset
+  lda #$02
+  sta (instAddrOffset + 1)
+  lda #$06
+  sta (memoffset + 1)
+  jsr ClearMemory
+InterpretLoop:
+  ldy #$00
+  lda (instAddrOffset), Y
+  cmp #$00
+  bne InterpretLoopNotZero
+  jmp InterpretLoopDone
+InterpretLoopNotZero:
+  cmp #$2B
+  bne InterpretNotPlus
+  jsr InterpretPlus
+  jmp InterpretLoopEnd
+InterpretNotPlus:
+  cmp #$2D
+  bne InterpretNotMinus
+  jsr InterpretMinus
+  jmp InterpretLoopEnd
+InterpretNotMinus:
+  cmp #$3C
+  bne InterpretNotLeftAngle
+  jsr InterpretLeftAngle
+  jmp InterpretLoopEnd
+InterpretNotLeftAngle:
+  cmp #$3E
+  bne InterpretNotRightAngle
+  jsr InterpretRightAngle
+  jmp InterpretLoopEnd
+InterpretNotRightAngle:
+  cmp #$5B
+  bne InterpretNotOpen
+  jsr InterpretOpen
+  jmp InterpretLoopEnd
+InterpretNotOpen:
+  cmp #$5D
+  bne InterpretNotClose
+  jsr InterpretClose
+  jmp InterpretLoopEnd
+InterpretNotClose:
+  cmp #$2E
+  bne InterpretNotOutput
+  jsr InterpretOutput
+  jmp InterpretLoopEnd
+InterpretNotOutput
+  cmp #$2C
+  bne InterpretLoopEnd
+  jsr InterpretInput
+  lda instAddrOffset
+  clc
+  adc #$01
+  sta instAddrOffset
+  lda (instAddrOffset + 1)
+  adc #$00
+  sta (instAddrOffset + 1)
+  jmp InterpretDone
+InterpretLoopEnd:
+  ldx err
+  cpx #$01
+  beq InterpretLoopDone
+  lda instAddrOffset
+  clc
+  adc #$01
+  sta instAddrOffset
+  lda (instAddrOffset + 1)
+  adc #$00
+  sta (instAddrOffset + 1)
+  jmp InterpretLoop
+InterpretLoopDone:
+  ldx #$00
+  stx instAddrOffset
+  stx col
+  stx row
+  stx rowadjusted
+  ldx #$02
+  stx (instAddrOffset + 1)
+  ldx err
+  cpx #$01
+  beq InterpretDone
+  ldx #$00
+  stx interpret
+  jsr Blank
+  lda #<(FinishedText)
+  sta addr
+  lda #>(FinishedText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(ContinueText)
+  sta addr
+  lda #>(ContinueText)
+  sta (addr + 1)
+  jsr NamDecompress
+  jsr ResetCursor
+  jsr ResetScroll
+InterpretDone:
+  rts
+
+InterpretPlus:
+  ldy #$00
+  lda (memoffset), Y
+  tax
+  inx
+  txa
+  sta (memoffset), Y
+  rts
+
+InterpretMinus:
+  ldy #$00
+  lda (memoffset), Y
+  tax
+  dex
+  txa
+  sta (memoffset), Y
+  rts
+
+InterpretLeftAngle:
+  lda memoffset
+  sec
+  sbc #$01
+  sta memoffset
+  lda (memoffset + 1)
+  sbc #$00
+  sta (memoffset + 1)
+  cmp #$05
+  bne InterpretLeftDone
+  ldx #$00
+  stx interpret
+  stx instAddrOffset
+  stx col
+  stx row
+  stx rowadjusted
+  ldx #$02
+  stx (instAddrOffset + 1)
+  ldx #$01
+  stx err
+  jsr Blank
+  lda #<(ErrorText)
+  sta addr
+  lda #>(ErrorText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(MemPtrUnderflowText)
+  sta addr
+  lda #>(MemPtrUnderflowText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(ContinueText)
+  sta addr
+  lda #>(ContinueText)
+  sta (addr + 1)
+  jsr NamDecompress
+  jsr ResetCursor
+  jsr ResetScroll
+InterpretLeftDone
+  rts
+
+InterpretRightAngle:
+  lda memoffset
+  clc
+  adc #$01
+  sta memoffset
+  lda (memoffset + 1)
+  adc #$00
+  sta (memoffset + 1)
+  cmp #$08
+  bne InterpretRightDone
+
+  ldx #$00
+  stx interpret
+  stx instAddrOffset
+  stx col
+  stx row
+  stx rowadjusted
+  ldx #$02
+  stx (instAddrOffset + 1)
+  ldx #01
+  stx err
+  jsr Blank
+  lda #<(ErrorText)
+  sta addr
+  lda #>(ErrorText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(MemPtrOverflowText)
+  sta addr
+  lda #>(MemPtrOverflowText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(ContinueText)
+  sta addr
+  lda #>(ContinueText)
+  sta (addr + 1)
+  jsr NamDecompress
+  jsr ResetCursor
+  jsr ResetScroll
+InterpretRightDone
+  rts
+
+InterpretOutput:
+  ldy row
+  cpy #$13
+  beq InterpretOutputDone
+  ldy #$00
+  lda (memoffset), Y
+  clc
+  cmp #$20
+  bcc InterpretOutputLessThan32
+  clc
+  cmp #$7F
+  bcs InterpretOutputGreaterThanEqual127
+  tay ; Subscribe to @SwiftOnSecurity for Corn Facts
+  jmp InterpretOutputPrintChar
+InterpretOutputLessThan32:
+  cmp #$0A
+  bne InterpretOutputNotNL
+  inc row
+  inc rowadjusted
+  lda #$00
+  sta col
+InterpretOutputIncRowDone:
+  jmp InterpretOutputDone
+InterpretOutputNotNL
+  cmp #$0D
+  bne InterpretOutputDone
+  lda #$00
+  sta col
+  jmp InterpretOutputDone
+InterpretOutputGreaterThanEqual127:
+  ldy #$7F
+InterpretOutputPrintChar:
+  jsr AdjustPrintAddr
+  jsr Blank
+  sta $2002
+  lda (printaddr + 1)
+  sta $2006
+  lda (printaddr)
+  sta $2006
+  sty $2007
+  jsr IncColRow
+InterpretOutputDone:
+  rts
+
+InterpretInput:
+  lda #$00
+  sta input
+  sta inputpointer
+  sta interpret
+  lda #$02
+  sta screen
+  jsr Blank
+  lda #<(InputText)
+  sta addr
+  lda #>(InputText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(InputInstructionData)
+  sta addr
+  lda #>(InputInstructionData)
+  sta (addr + 1)
+  jsr NamDecompress
+  jsr DrawInput
+  jsr ResetScroll
+  rts 
+
+InterpretOpen:
+  lda #$00
+  sta square
+  sta (square + 1)
+  tay ; Subscribe to @SwiftOnSecurity for Corn Facts
+  lda (memoffset), Y
+  cmp #$00
+  bne InterpretOpenDone
+InterpretOpenLoop:
+  lda instAddrOffset
+  clc
+  adc #$01
+  sta instAddrOffset
+  lda (instAddrOffset + 1)
+  adc #$00
+  sta (instAddrOffset + 1)
+  cmp #$06
+  bne InterpretOpenLoopContinue
+
+  ldx #$00
+  stx interpret
+  stx instAddrOffset
+  stx col
+  stx row
+  stx rowadjusted
+  ldx #$02
+  stx (instAddrOffset + 1)
+  ldx #01
+  stx err
+  jsr Blank
+  lda #<(ErrorText)
+  sta addr
+  lda #>(ErrorText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(NoMatchingRightText)
+  sta addr
+  lda #>(NoMatchingRightText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(ContinueText)
+  sta addr
+  lda #>(ContinueText)
+  sta (addr + 1)
+  jsr NamDecompress
+  jsr ResetCursor
+  jsr ResetScroll
+  jmp InterpretOpenDone
+InterpretOpenLoopContinue:
+  ldy #$00
+  lda (instAddrOffset), Y
+  cmp #$5B
+  bne InterpretOpenLoopNotOpen
+  lda (square + 1)
+  clc
+  adc #$01
+  sta (square + 1)
+  lda square
+  adc #$00
+  sta square
+InterpretOpenLoopNotOpen:
+  cmp #$5D
+  bne InterpretOpenLoop
+  lda (square + 1)
+  sec
+  sbc #$01
+  sta (square + 1)
+  lda square
+  sbc #$00
+  sta square
+  cmp #$FF
+  bne InterpretOpenLoop
+InterpretOpenDone:
+  rts
+
+InterpretClose:
+  lda #$00
+  sta square
+  sta (square + 1)
+InterpretCloseLoop:
+  lda instAddrOffset
+  sec
+  sbc #$01
+  sta instAddrOffset
+  lda (instAddrOffset + 1)
+  sbc #$00
+  sta (instAddrOffset + 1)
+  cmp #$01
+  bne InterpretCloseLoopContinue
+
+  ldx #$00
+  stx interpret
+  stx instAddrOffset
+  stx col
+  stx row
+  stx rowadjusted
+  ldx #$02
+  stx (instAddrOffset + 1)
+  ldx #01
+  stx err
+  jsr Blank
+  lda #<(ErrorText)
+  sta addr
+  lda #>(ErrorText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(NoMatchingLeftText)
+  sta addr
+  lda #>(NoMatchingLeftText)
+  sta (addr + 1)
+  jsr NamDecompress
+  lda #<(ContinueText)
+  sta addr
+  lda #>(ContinueText)
+  sta (addr + 1)
+  jsr NamDecompress
+  jsr ResetCursor
+  jsr ResetScroll
+  jmp InterpretCloseDone
+InterpretCloseLoopContinue:
+  ldy #$00
+  lda (instAddrOffset), Y
+  cmp #$5D
+  bne InterpretCloseLoopNotClose
+  lda (square + 1)
+  clc
+  adc #$01
+  sta (square + 1)
+  lda square
+  adc #$00
+  sta square
+InterpretCloseLoopNotClose:
+  cmp #$5B
+  bne InterpretCloseLoop
+  lda (square + 1)
+  sec
+  sbc #$01
+  sta (square + 1)
+  lda square
+  sbc #$00
+  sta square
+  cmp #$FF
+  bne InterpretCloseLoop
+  lda instAddrOffset
+  sec
+  sbc #$01
+  sta instAddrOffset
+  lda (instAddrOffset + 1)
+  sbc #$00
+  sta (instAddrOffset + 1)
+InterpretCloseDone:
+  rts
+
+AdjustPrintAddr:
+  lda col
+  clc
+  adc #$C2
+  sta printaddr
+  lda rowadjusted
+  asl
+  asl
+  asl
+  asl
+  asl
+  clc
+  adc printaddr
+  sta printaddr
+  lda #$00
+  adc #$00
+  tax
+  lda row
+  lsr
+  lsr
+  lsr
+  clc
+  adc #$20
+  sta (printaddr + 1)
+  txa
+  adc (printaddr + 1)
+  sta (printaddr + 1)
+  rts
+
+;set up and enable NMI
+EnableNMI:
+  lda #%10001000
+  sta $2000
+  rts
+
+;set up the PPU
+Draw:
+  lda #%00001010 ; Disabled sprites
+  sta $2001
+  rts
+
+AllowDraw:
+  lda #$01
+  sta drawAllowed
+  jsr EnableNMI
+  rts
+
+DisableNMI:
+  lda #$00
+  sta drawAllowed
+  sta $2000
+  rts
+
+Blank:
+  lda #$00
+  sta $2001    ; disable rendering
+  sta drawAllowed
+  jsr DisableNMI
+  rts
+
+;Update controller input and chack controller values
+Update:
+  jsr LatchController
+  jsr PollController
+  jsr CheckSelect
+  jsr CheckUp
+  jsr CheckDown
+  jsr CheckLeft
+  jsr CheckRight
+  jsr CheckA
+  jsr CheckB
+  jsr CheckStart
+  ldx screen
+  cpx #$00
+  bne UpdateDone
+  jsr CheckAUp
+  jsr CheckADown
+  jsr CheckALeft
+  jsr CheckARight
+  jsr CheckBUp
+  jsr CheckBDown
+  jsr CheckBLeft
+  jsr CheckBRight
+UpdateDone:
+  rts
+
+ResetScroll:
+  lda #$00
+  sta $2005
+  sta $2005 ;Reset scroll by passing #$0000 to $2005
+  jsr AllowDraw
+  rts
+
+ResetCursor:
+  lda #$C2
+  sta cursoraddr
+  lda #$20
+  sta (cursoraddr) + 1
+  rts
+
+BlinkCursor:
+  ldx screen
+  cpx #$00
+  beq BlinkCursorContinue
+  dec frames
+  jmp BlinkCursorDone
+BlinkCursorContinue
+  lda $2002 ;read PPU to reset write toggle
+  lda (cursoraddr + 1)
+  sta $2006
+  lda cursoraddr
+  sta $2006
+  lda cursorframe
+  cmp #$00
+  bne BlinkCursorNot0
+  lda #$01
+  sta cursorframe
+  jmp BlinkCursorDraw
+BlinkCursorNot0:
+  lda #$00
+  sta cursorframe
+BlinkCursorDraw:
+  sta $2007
+BlinkCursorDone:
+  rts
+
+DrawNewLine:
+  ldx widthOffset
+DrawNewLineLoop:
+  cpx width
+  beq DrawNewLineDone
+  ;; Continue if widthOffset is not width
+  inx
+  lda #$00
+  sta $2007
+  jmp DrawNewLineLoop
+DrawNewLineDone:
+  dex
+  stx widthOffset
+  rts
+
+;; Nametable decompression algorithm
+NamDecompress:
+  lda $2002 ;read PPU to reset write toggle
+  ldy #$00
+  ;; Reinitialize two/Ct/St to 0
+  sty twoCt
+  sty twoSt
+  sty widthOffset
+  lda (addr), y
+  sta width
+  iny
+  lda (addr), y
+  sta height
+  iny
+  lda (addr), y
+  sta drawAddr
+  sta $2006
+  iny
+  lda (addr), y
+  sta (drawAddr + 1)
+  sta $2006
+  iny
+  tya
+  clc
+  adc addr
+  sta addr
+  lda (addr + 1)
+  adc #$00
+  sta (addr + 1)
+NamDecompressLoop:
+  ;; Load instruction pointer to y
+  ldy #$00
+  ;; Load addr[y] to A
+  lda (addr), y
+  cmp #$02
+  bne NamDecompressNot2
+  ;; Continue if A is 2
+  ldx twoSt
+  cpx #$00
+  bne NamDecompress2Back
+  ;; Continue if twoSt is 0
+  iny
+  lda (addr), y
+  cmp #$02
+  bne NamDecompress2Init
+  sta $2007 ;; Print 2
+  jmp NamDecompress2Done
+NamDecompress2Init:
+  dec widthOffset
+  ldx #$01
+  stx twoSt ;; Start two loop
+  lda (addr), y
+  sta twoCt ;; Set two count
+  jmp NamDecompress2Done
+NamDecompress2Back:
+  dec widthOffset
+  dec twoCt
+  ldx twoCt
+  cpx #$00
+  bne NamDecompress2BackLoop
+  ;; Continue if twoCt is 0
+  ldx #$00
+  stx twoSt
+  jmp NamDecompress2Done
+NamDecompress2BackLoop:
+  sec
+  lda addr
+  sbc #$01
+  sta addr
+  lda (addr + 1)
+  sbc #$00
+  sta (addr + 1)
+  lda (addr), y
+  cmp #$02
+  bne NamDecompress2BackLoop
+  ;; Continue if addr[y] is 02
+  iny
+  lda (addr), y
+  jmp NamDecompress2Done
+NamDecompress2Done:
+  jmp NamLoopDone
+NamDecompressNot2:
+  cmp #$00
+  bne NamDecompressPrintValue
+  jsr DrawNewLine
+  jmp NamLoopDone
+NamDecompressPrintValue:
+  sta $2007
+NamLoopDone:
+  iny
+  tya
+  clc
+  adc addr
+  sta addr
+  lda (addr + 1)
+  adc #$00
+  sta (addr + 1)
+  inc widthOffset
+  ldx widthOffset
+  cpx width
+  beq NamDecompressEndOfLine
+  ;; Continue if widthOffset is not width
+  jmp NamDecompressLoop
+NamDecompressEndOfLine:
+  ;; Continue if widthOffset is width
+  lda $2002 ;read PPU to reset write toggle
+  ldx #$00
+  stx widthOffset
+  clc
+  lda (drawAddr + 1)
+  adc #$20
+  sta (drawAddr + 1)
+  lda drawAddr
+  adc #$00
+  sta drawAddr
+  sta $2006
+  lda (drawAddr + 1)
+  sta $2006
+  dec height
+  ldx height
+  cpx #$00
+  beq NamDecompressDone
+  ;; Continue if height is not 0
+  jmp NamDecompressLoop
+NamDecompressDone:
+  rts
+
+SetAttribute:
+  lda $2002 ;read PPU to reset write toggle
+  lda #$23
+  sta $2006
+  lda #$C0
+  sta $2006
+  lda #$00
+  tax
+SetAttributeLoop:
+  sta $2007
+  inx
+  cpx #$20
+  bne SetAttributeLoop
+  rts
+
+SetPalette:
+  lda $2002 ;read PPU to reset write toggle
+  lda #$3f
+  sta $2006
+  lda #$00 ;point $2006 to the nametable (0x3F00)
+  sta $2006
+  txa
+  ldx #$08
+  sty tmp
+SetPaletteLoop:
+  sta $2007
+  sty $2007
+  ldy #$21
+  sty $2007
+  ldy tmp
+  sty $2007
+  dex
+  cpx #$00
+  bne SetPaletteLoop
+  jsr ResetScroll
+  rts
+  
+AttributesSlides:
+  .byte $00, $00, $00, $00, $00, $00, $00, $00
+  .byte $00, $55, $55, $55, $55, $55, $55, $00
+  .byte $00, $55, $55, $55, $55, $55, $55, $00
+  .byte $00, $55, $55, $55, $55, $55, $55, $00
+  .byte $00, $55, $55, $55, $55, $55, $55, $00
+  .byte $00, $55, $55, $55, $55, $55, $55, $00
+  .byte $00, $00, $00, $00, $00, $00, $00, $00
+  .byte $00, $00, $00, $00, $00, $00, $00, $00
+
+BlankMap:
+  .byte $20, $1E, $20, $00
+  .byte $02, $1E, $00, $02
+
+TitleBoard:
+  .byte $1C, $12, $20, $42
+  .byte $03, $02, $1A, $09, $02, $04
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, " ", $BA, $BB, $BC, $BD, $BE, $BF, $CA, $CB, $BA, $CC, " ", $BA, $BD, $CD, $D0, $BA, "  ", $BA, $BA, $CF, $BA, " ", $BA, " ", $08
+  .byte $07, " ", $BA, $D2, $D3, $BD, $D4, $D5, $D6, $D7, $D8, $D9, " ", $BA, $BD, $DA, $DB, $BA, "  ", $BA, $DC, " ", $BA, " ", $BA, " ", $08
+  .byte $07, " ", $BA, $DD, $BA, $BD, $DE, $DF, $E0, $E1, $BA, $BA, $E2, $BA, $BD, $E3, $E4, $BA, "  ", $BA, $E5, " ", $BA, $E6, $BA, " ", $08
+  .byte $07, " ", $E5, $E5, $E8, $E9, $EA, $EB, $EC, $E5, " ", $E5, $ED, $E5, $E9, $EA, $EE, $E5, "  ", $E5, "  ", $EF, $E5, $E8, " ", $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, "   PROGRAMMING LANGUAGE   ", $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, " ", $02, $18, $FF, $02, " ", $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, "  I N T E R P R E T E R   ", $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, " ", $02, $18, $FF, $02, " ", $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $05, $02, $1A, $0A, $02, $06
+  .byte $1A, $1B, $1C, $1D, $1E, $1F, $0C, $0D, $02, $0F, " ", $02, $0B, $0C, $0D, $0E, $0F
+
+TitleOptions:
+  .byte $13, $05, $22, $C8
+  .byte "START INTERPRETER", $00
+  .byte $00
+  .byte "TUTORIAL", $00
+  .byte $00
+  .byte "ABOUT THE DEVELOPER"
+
+TitleCursor:
+  .byte $01, $05, $22, $C6
+  .byte $02, $05, $00, $02
+
+TopData:
+  .byte $1C, $03, $20, $42
+  .byte $A0, $A1, $A2, $A3, $A4, $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, "    ", $10, $11, $12, $13, $14, $15, $16, $17, $18, $16 
+  .byte $B0, $B1, $B2, $B3, $B4, $B5, $B6, $B7, $B8, $B9, $02, $0A, " ", $02, $1A, $1B, $1C, $1D, $1E, $1F, $0C, $0D
+  .byte $C0, $C1, $C2, $C3, $C4, $C5, $C6, $C7, $C8, $C9, $02, $0D, " ", $02, $0B, $0C, $0D, $0E, $0F
+
+FrameData:
+  .byte $1C, $17, $20, $42
+  .byte $03, $02, $1A, $09, $02, $04
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $07, $02, $1A, " ", $02, $08
+  .byte $05, $02, $1A, $0A, $02, $06
+
+Tutorial1:
+  .byte $18, $13, $20, $84
+  .byte "Brain Fu is a Turing", $00
+  .byte "Complete programming", $00
+  .byte "language made up of 8", $00
+  .byte "instructions, which are "
+  .byte "represented by the", $00
+  .byte "following symbols:", $00
+  .byte $00
+  .byte $00
+  .byte "    < > + - , . [ ]", $00
+  .byte $00
+  .byte $00
+  .byte "Each instruction does a "
+  .byte "specific action and", $00
+  .byte "multiple instructions", $00
+  .byte "can be strung together", $00
+  .byte "to create a Brain Fu", $00
+  .byte "program.", $00
+  .byte $00
+  .byte $02, $14, " ", $02, "1/12"
+
+Tutorial2:
+  .byte $18, $13, $20, $84
+  .byte "These instructions are", $00
+  .byte "used to manipulate a", $00
+  .byte "one dimensional tape of "
+  .byte "memory comprised of", $00
+  .byte "memory cells.", $00
+  .byte $00
+  .byte "A memory pointer points "
+  .byte "to the memory cell you", $00
+  .byte "can manipulate.", $00
+  .byte $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $02, $04, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $00
+  .byte $00
+  .byte $00
+  .byte $02, $14, " ", $02, "2/12"
+
+Tutorial3:
+  .byte $18, $13, $20, $84
+  .byte "Brain Fu instructions", $00
+  .byte "are executed one at a", $00
+  .byte "time in order.  There is"
+  .byte "an instruction pointer", $00
+  .byte "that points to the", $00
+  .byte "instruction that will be"
+  .byte "executed.", $00
+  .byte $00
+  .byte $00
+  .byte $00
+  .byte $00
+  .byte " ", $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, " ++[->++]]>-", $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $F5, $F6, " ", $F7, $00
+  .byte $02, $05, $00, $02
+  .byte $02, $14, " ", $02, "3/12"
+
+Tutorial4:
+  .byte $18, $13, $20, $84
+  .byte "+ is used to increment", $00
+  .byte "the current memory cell "
+  .byte "by 1."
+  .byte $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $02, $04, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $00
+  .byte "After applying +, the ", $00
+  .byte "memory cell value", $00
+  .byte "changed from 0 to 1.", $00
+  .byte $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $FE, "1", $02, $03, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $02, $14, " ", $02, "4/12"
+
+Tutorial5:
+  .byte $18, $13, $20, $84
+  .byte "- is used to decrement", $00
+  .byte "the current memory cell "
+  .byte "by 1."
+  .byte $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $FE, "1", $02, $03, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $00
+  .byte "After applying -, the ", $00
+  .byte "memory cell value", $00
+  .byte "changed from 1 to 0.", $00
+  .byte $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $02, $04, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $02, $14, " ", $02, "5/12"
+
+Tutorial6:
+  .byte $18, $13, $20, $84
+  .byte "> is used to move the", $00
+  .byte "memory pointer to the", $00
+  .byte "right by 1."
+  .byte $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $02, $04, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $00
+  .byte "After applying >, the ", $00
+  .byte "memory pointer moved", $00
+  .byte "from the first to the", $00
+  .byte "second memory cell.", $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $02, $04, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "    ", $F7, $00
+  .byte $02, $14, " ", $02, "6/12"
+
+Tutorial7:
+  .byte $18, $13, $20, $84
+  .byte "< is used to move the", $00
+  .byte "memory pointer to the", $00
+  .byte "left by 1."
+  .byte $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $02, $04, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "    ", $F7, $00
+  .byte $00
+  .byte "After applying <, the ", $00
+  .byte "memory pointer moved", $00
+  .byte "from the second to the", $00
+  .byte "first memory cell.", $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $02, $04, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $02, $14, " ", $02, "7/12"
+
+Tutorial8:
+  .byte $18, $13, $20, $84
+  .byte ", is used to ask the", $00
+  .byte "user for an 8 bit input."
+  .byte "That value is stored in "
+  .byte "the current memory cell."
+  .byte $00
+  .byte $00
+  .byte "  User Input: ", $F0, $F1, $F0, $F0, $F0, $F0, $F0, $F1, $00
+  .byte $00
+  .byte $00
+  .byte "The user input value of "
+  .byte "65 is stored in the", $00
+  .byte "memory cell.", $00
+  .byte $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $FF, $FF, $02, $03, $FC, $FF, $02, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $FE, "65", $02, $03, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $FF, $FF, $02, $03, $FD, $FF, $02, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $02, $14, " ", $02, "8/12"
+
+Tutorial9:
+  .byte $18, $13, $20, $84
+  .byte ". is used to print the", $00
+  .byte "current memory cell", $00
+  .byte "value as a 7 bit ASCII", $00
+  .byte "encoded character.", $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $FF, $FF, $02, $03, $FC, $FF, $02, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $FE, "65", $02, $03, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $FF, $FF, $02, $03, $FD, $FF, $02, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $00
+  .byte $00
+  .byte "The memory cell value of"
+  .byte "65 prints out:", $00
+  .byte $00
+  .byte $00
+  .byte $02, $0B, " ", $02, "A", $00
+  .byte $00
+  .byte $00
+  .byte $02, $14, " ", $02, "9/12"
+
+Tutorial10:
+  .byte $18, $13, $20, $84
+  .byte "[ is used to make the", $00
+  .byte "instruction pointer jump"
+  .byte "past the matching ]", $00
+  .byte "instruction if the ", $00
+  .byte "memory cell value is 0. "
+  .byte "Square brackets can be", $00
+  .byte "nested inside each other"
+  .byte $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, " [->+<]>+", $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $F5, $F6, "  ", $F7, $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $02, $04, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, " [->+<]>+", $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $F5, $F6, "        ", $F7, $00
+  .byte $02, $13, " ", $02, "10/12"
+
+Tutorial11:
+  .byte $18, $13, $20, $84
+  .byte "If [ is used and the", $00
+  .byte "current memory cell", $00
+  .byte "value is not 0, the", $00
+  .byte "instruction pointer will"
+  .byte "move forward by 1 like", $00
+  .byte "usual.", $00
+  .byte $00
+  .byte $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, " +[->+<]>+", $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $F5, $F6, "   ", $F7, $00
+  .byte $00
+  .byte $02, $09, " ", $02, $F8, $02, $03, $FF, $FC, $02, $FF, $F9, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $B8, $B9, " ", $FE, "1", $02, $03, $FE, "0", $02, $FE, $19, $19, $19, $00
+  .byte $02, $09, " ", $02, $FA, $02, $03, $FF, $FD, $02, $FF, $FB, $00
+  .byte "  ", $B4, $B5, $B6, $B7, $F5, $F6, "  ", $F7, $00
+  .byte $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, " +[->+<]>+", $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $F5, $F6, "    ", $F7, $00
+  .byte $02, $13, " ", $02, "11/12"
+
+Tutorial12:
+  .byte $18, $13, $20, $84
+  .byte "] is used to force the", $00
+  .byte "instruction pointer back"
+  .byte "to the matching [", $00
+  .byte "instruction.  This is", $00
+  .byte "used to create loops.", $00
+  .byte $00
+  .byte $00
+  .byte $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, " +[->+<]>+", $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $F5, $F6, "        ", $F7, $00
+  .byte $00
+  .byte $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $AB, $AC, $AD, " +[->+<]>+", $00
+  .byte "  ", $A5, $A6, $A7, $A8, $A9, $AA, $F5, $F6, "   ", $F7, $00
+  .byte $00
+  .byte $00
+  .byte $00
+  .byte $00
+  .byte $02, $13, " ", $02, "12/12"
+
+AboutData:
+  .byte $18, $13, $20, $84
+  .byte "Vi Grey is a techology", $00
+  .byte "researcher and software "
+  .byte "engineer with a general "
+  .byte "focus on information", $00
+  .byte "theory research.  He", $00
+  .byte "teaches cryptography", $00
+  .byte "workshops and speaks", $00
+  .byte "about abusing file", $00
+  .byte "format specifications to"
+  .byte "hide information in", $00
+  .byte "unusual ways.", $00
+  .byte $00
+  .byte $00
+  .byte "Visit vigrey.com/blog to"
+  .byte "read about Vi's recent", $00
+  .byte "projects.", $00
+  .byte $00
+  .byte $00
+  .byte "telnet vigrey.com", $00
+
+
+TutorialFirstInstructions:
+  .byte $1A, $02, $23, $43
+  .byte $80, ":", $AE, $AF, $02, $0C, " ", $02, $86, $87, $88, ":", $F2, $F3, $F4, $C7, $C8, $C9
+  .byte $81, ":", $F2, $F3, $F4, $C7, $C8, $C9, $00
+
+TutorialMiddleInstructions:
+  .byte $1A, $02, $23, $43
+  .byte $80, ":", $AE, $AF, $02, $0C, " ", $02, $86, $87, $88, ":", $F2, $F3, $F4, $C7, $C8, $C9
+  .byte $81, ":", $9E, $9F, $00
+
+TutorialLastInstructions:
+  .byte $1A, $02, $23, $43
+  .byte $80, ":", $F2, $F3, $F4, $C7, $C8, $C9, $02, $08, " ", $02, $86, $87, $88, ":", $F2, $F3, $F4, $C7, $C8, $C9
+  .byte $81, ":", $9E, $9F, $00
+
+AboutInstructionData:
+  .byte $1A, $01, $23, $43
+  .byte $81, ":", $F2, $F3, $F4, $C7, $C8, $C9, $02, $08, " ", $02, $86, $87, $88, ":", $F2, $F3, $F4, $C7, $C8, $C9
+
+InstructionData:
+  .byte $1A, $02, $23, $43
+  .byte $80, $82, ":+ ", $80, $83, ":- ", $80, $84, ":< ", $80, $85, ":>"
+  .byte " ", $86, $87, $88, ":", $90, $91
+  .byte $81, $82, ":. ", $81, $83, ":, ", $81, $84, ":[ ", $81, $85, ":]"
+  .byte " ", $89, $8A, $8B, ":", $92, $93
+
+InputInstructionData:
+  .byte $1A, $02, $23, $43
+  .byte $82, "/", $83, ":", $8C, $8D, $8E, $8F
+  .byte $02, $0A, " ", $02, $86, $87, $88, ":", $94, $95, $96, $97
+  .byte $84, "/", $85, ":", $9C, $9D, $8E, $8F, $00
+
+ReadyText:
+  .byte $1C, $14, $20, $A2
+  .byte "READY", $02, $14, $00, $02
+
+InputText:
+  .byte $1C, $01, $20, $A2
+  .byte "INPUT:", $00
+
+FinishedText:
+  .byte $1C, $01, $20, $A2
+  .byte "FINISHED", $00
+
+ContinueText:
+  .byte $1C, $02, $23, $42
+  .byte $02, $13, " ", $02
+  .byte $86, $87, $88, ":", $94, $98, $99, $9A, " ", $00
+
+ScreenBlankData:
+  .byte $1C, $16, $20, $C2
+  .byte $02, $16, $00, $02
+
+InstructionBlank:
+  .byte $1A, $02, $23, $43
+  .byte $00, $00
+
+ProcessingText:
+  .byte $1C, $01, $20, $A2
+  .byte "PROCESSING", $02, $17, $00, $02
+
+ErrorText:
+  .byte $1C, $01, $20, $A2
+  .byte "ERROR", $00
+
+NoMatchingLeftText:
+  .byte $1C, $13, $20, $C2
+  .byte "NO MATCHING [ INSTRUCTION", $02, $13, $00, $02
+
+NoMatchingRightText:
+  .byte $1C, $13, $20, $C2
+  .byte "NO MATCHING ] INSTRUCTION", $02, $13, $00, $02
+
+MemPtrUnderflowText:
+  .byte $1C, $13, $20, $C2
+  .byte "MEMORY POINTER OUT OF BOUNDS"
+  .byte "(-1)", $02, $12, $00, $02
+
+MemPtrOverflowText:
+  .byte $1C, $13, $20, $C2
+  .byte "MEMORY POINTER OUT OF BOUNDS"
+  .byte "(513)", $02, $12, $00, $02
+
+SlidesList:
+  .dw Tutorial1
+  .dw Tutorial2
+  .dw Tutorial3
+  .dw Tutorial4
+  .dw Tutorial5
+  .dw Tutorial6
+  .dw Tutorial7
+  .dw Tutorial8
+  .dw Tutorial9
+  .dw Tutorial10
+  .dw Tutorial11
+  .dw Tutorial12
+
+  .pad  $E000
+
+  .incbin "graphics/tileset.chr"
+
+  .dw   NMI
+  .dw   RESET
+  .dw   0
+
+  .base $0000
+
+  .incbin "graphics/tileset.chr"
+
+  .dw   NMI
+  .dw   RESET
+  .dw   0
diff --git a/src/graphics/tileset.chr b/src/graphics/tileset.chr
new file mode 100755
index 0000000..2908de1
Binary files /dev/null and b/src/graphics/tileset.chr differ