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Initial commit

master
Austin Morlan 9 months ago
commit
8767703617
Signed by: austin
GPG Key ID: FD6B27654AF5E348
  1. 10
      README.md
  2. 13
      build.sh
  3. 24
      code/constants.inc
  4. 913
      code/hardware.inc
  5. 731
      code/main.asm
  6. 259
      code/ops.asm
  7. 254
      code/signals.asm
  8. 294
      code/tick.asm

10
README.md

@ -0,0 +1,10 @@
# Breadboard Game Boy
A Game Boy version of the 8-bit computer built by Ben Eater in his [series of videos](https://eater.net/8bit).
[Here is a blog post about it.](https://austinmorlan.com/posts/8bit_breadboard_gameboy/)
![Emulator Demo](https://austinmorlan.com/posts/8bit_breadboard_gameboy/media/count_emu.gif)
![Hardware Demo](https://austinmorlan.com/posts/8bit_breadboard_gameboy/media/count_hw.gif)

13
build.sh

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#!/usr/bin/env bash
CODE_DIR=code
BUILD_DIR=build
TEMP_DIR=$BUILD_DIR/temp
GAME_NAME=8bit
mkdir -p $TEMP_DIR
rgbasm -Weverything -E -i $CODE_DIR -o $TEMP_DIR/$GAME_NAME.obj $CODE_DIR/main.asm
rgblink -n $BUILD_DIR/$GAME_NAME.sym -m $BUILD_DIR/$GAME_NAME.map -o $BUILD_DIR/$GAME_NAME.gb $TEMP_DIR/$GAME_NAME.obj
rgbfix -v -p0 $BUILD_DIR/$GAME_NAME.gb

24
code/constants.inc

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LED_OFF EQU $25
LED_ON EQU $26
CTRL_HT EQU 7
CTRL_MI EQU 6
CTRL_RI EQU 5
CTRL_RO EQU 4
CTRL_IO EQU 3
CTRL_II EQU 2
CTRL_AI EQU 1
CTRL_AO EQU 0
CTRL_EO EQU 7
CTRL_SU EQU 6
CTRL_BI EQU 5
CTRL_OI EQU 4
CTRL_CE EQU 3
CTRL_CO EQU 2
CTRL_JP EQU 1
CTRL_FI EQU 0
FLAG_C EQU 1
FLAG_Z EQU 0

913
code/hardware.inc

@ -0,0 +1,913 @@
;*
;* Gameboy Hardware definitions
;*
;* Based on Jones' hardware.inc
;* And based on Carsten Sorensen's ideas.
;*
;* Rev 1.1 - 15-Jul-97 : Added define check
;* Rev 1.2 - 18-Jul-97 : Added revision check macro
;* Rev 1.3 - 19-Jul-97 : Modified for RGBASM V1.05
;* Rev 1.4 - 27-Jul-97 : Modified for new subroutine prefixes
;* Rev 1.5 - 15-Aug-97 : Added _HRAM, PAD, CART defines
;* : and Nintendo Logo
;* Rev 1.6 - 30-Nov-97 : Added rDIV, rTIMA, rTMA, & rTAC
;* Rev 1.7 - 31-Jan-98 : Added _SCRN0, _SCRN1
;* Rev 1.8 - 15-Feb-98 : Added rSB, rSC
;* Rev 1.9 - 16-Feb-98 : Converted I/O registers to $FFXX format
;* Rev 2.0 - : Added GBC registers
;* Rev 2.1 - : Added MBC5 & cart RAM enable/disable defines
;* Rev 2.2 - : Fixed NR42,NR43, & NR44 equates
;* Rev 2.3 - : Fixed incorrect _HRAM equate
;* Rev 2.4 - 27-Apr-13 : Added some cart defines (AntonioND)
;* Rev 2.5 - 03-May-15 : Fixed format (AntonioND)
;* Rev 2.6 - 09-Apr-16 : Added GBC OAM and cart defines (AntonioND)
;* Rev 2.7 - 19-Jan-19 : Added rPCMXX (ISSOtm)
;* Rev 2.8 - 03-Feb-19 : Added audio registers flags (Álvaro Cuesta)
;* Rev 2.9 - 28-Feb-20 : Added utility rP1 constants
;* Rev 3.0 - 27-Aug-20 : Register ordering, byte-based sizes, OAM additions, general cleanup (Blitter Object)
; If all of these are already defined, don't do it again.
IF !DEF(HARDWARE_INC)
HARDWARE_INC SET 1
rev_Check_hardware_inc : MACRO
;NOTE: REVISION NUMBER CHANGES MUST BE ADDED
;TO SECOND PARAMETER IN FOLLOWING LINE.
IF \1 > 3.0 ;PUT REVISION NUMBER HERE
WARN "Version \1 or later of 'hardware.inc' is required."
ENDC
ENDM
_VRAM EQU $8000 ; $8000->$9FFF
_VRAM8000 EQU _VRAM
_VRAM8800 EQU _VRAM+$800
_VRAM9000 EQU _VRAM+$1000
_SCRN0 EQU $9800 ; $9800->$9BFF
_SCRN1 EQU $9C00 ; $9C00->$9FFF
_SRAM EQU $A000 ; $A000->$BFFF
_RAM EQU $C000 ; $C000->$CFFF / $C000->$DFFF
_RAMBANK EQU $D000 ; $D000->$DFFF
_OAMRAM EQU $FE00 ; $FE00->$FE9F
_IO EQU $FF00 ; $FF00->$FF7F,$FFFF
_AUD3WAVERAM EQU $FF30 ; $FF30->$FF3F
_HRAM EQU $FF80 ; $FF80->$FFFE
; *** MBC5 Equates ***
rRAMG EQU $0000 ; $0000->$1fff
rROMB0 EQU $2000 ; $2000->$2fff
rROMB1 EQU $3000 ; $3000->$3fff - If more than 256 ROM banks are present.
rRAMB EQU $4000 ; $4000->$5fff - Bit 3 enables rumble (if present)
;***************************************************************************
;*
;* Custom registers
;*
;***************************************************************************
; --
; -- P1 ($FF00)
; -- Register for reading joy pad info. (R/W)
; --
rP1 EQU $FF00
P1F_5 EQU %00100000 ; P15 out port, set to 0 to get buttons
P1F_4 EQU %00010000 ; P14 out port, set to 0 to get dpad
P1F_3 EQU %00001000 ; P13 in port
P1F_2 EQU %00000100 ; P12 in port
P1F_1 EQU %00000010 ; P11 in port
P1F_0 EQU %00000001 ; P10 in port
P1F_GET_DPAD EQU P1F_5
P1F_GET_BTN EQU P1F_4
P1F_GET_NONE EQU P1F_4 | P1F_5
; --
; -- SB ($FF01)
; -- Serial Transfer Data (R/W)
; --
rSB EQU $FF01
; --
; -- SC ($FF02)
; -- Serial I/O Control (R/W)
; --
rSC EQU $FF02
; --
; -- DIV ($FF04)
; -- Divider register (R/W)
; --
rDIV EQU $FF04
; --
; -- TIMA ($FF05)
; -- Timer counter (R/W)
; --
rTIMA EQU $FF05
; --
; -- TMA ($FF06)
; -- Timer modulo (R/W)
; --
rTMA EQU $FF06
; --
; -- TAC ($FF07)
; -- Timer control (R/W)
; --
rTAC EQU $FF07
TACF_START EQU %00000100
TACF_STOP EQU %00000000
TACF_4KHZ EQU %00000000
TACF_16KHZ EQU %00000011
TACF_65KHZ EQU %00000010
TACF_262KHZ EQU %00000001
; --
; -- IF ($FF0F)
; -- Interrupt Flag (R/W)
; --
rIF EQU $FF0F
; --
; -- AUD1SWEEP/NR10 ($FF10)
; -- Sweep register (R/W)
; --
; -- Bit 6-4 - Sweep Time
; -- Bit 3 - Sweep Increase/Decrease
; -- 0: Addition (frequency increases???)
; -- 1: Subtraction (frequency increases???)
; -- Bit 2-0 - Number of sweep shift (# 0-7)
; -- Sweep Time: (n*7.8ms)
; --
rNR10 EQU $FF10
rAUD1SWEEP EQU rNR10
AUD1SWEEP_UP EQU %00000000
AUD1SWEEP_DOWN EQU %00001000
; --
; -- AUD1LEN/NR11 ($FF11)
; -- Sound length/Wave pattern duty (R/W)
; --
; -- Bit 7-6 - Wave Pattern Duty (00:12.5% 01:25% 10:50% 11:75%)
; -- Bit 5-0 - Sound length data (# 0-63)
; --
rNR11 EQU $FF11
rAUD1LEN EQU rNR11
; --
; -- AUD1ENV/NR12 ($FF12)
; -- Envelope (R/W)
; --
; -- Bit 7-4 - Initial value of envelope
; -- Bit 3 - Envelope UP/DOWN
; -- 0: Decrease
; -- 1: Range of increase
; -- Bit 2-0 - Number of envelope sweep (# 0-7)
; --
rNR12 EQU $FF12
rAUD1ENV EQU rNR12
; --
; -- AUD1LOW/NR13 ($FF13)
; -- Frequency low byte (W)
; --
rNR13 EQU $FF13
rAUD1LOW EQU rNR13
; --
; -- AUD1HIGH/NR14 ($FF14)
; -- Frequency high byte (W)
; --
; -- Bit 7 - Initial (when set, sound restarts)
; -- Bit 6 - Counter/consecutive selection
; -- Bit 2-0 - Frequency's higher 3 bits
; --
rNR14 EQU $FF14
rAUD1HIGH EQU rNR14
; --
; -- AUD2LEN/NR21 ($FF16)
; -- Sound Length; Wave Pattern Duty (R/W)
; --
; -- see AUD1LEN for info
; --
rNR21 EQU $FF16
rAUD2LEN EQU rNR21
; --
; -- AUD2ENV/NR22 ($FF17)
; -- Envelope (R/W)
; --
; -- see AUD1ENV for info
; --
rNR22 EQU $FF17
rAUD2ENV EQU rNR22
; --
; -- AUD2LOW/NR23 ($FF18)
; -- Frequency low byte (W)
; --
rNR23 EQU $FF18
rAUD2LOW EQU rNR23
; --
; -- AUD2HIGH/NR24 ($FF19)
; -- Frequency high byte (W)
; --
; -- see AUD1HIGH for info
; --
rNR24 EQU $FF19
rAUD2HIGH EQU rNR24
; --
; -- AUD3ENA/NR30 ($FF1A)
; -- Sound on/off (R/W)
; --
; -- Bit 7 - Sound ON/OFF (1=ON,0=OFF)
; --
rNR30 EQU $FF1A
rAUD3ENA EQU rNR30
; --
; -- AUD3LEN/NR31 ($FF1B)
; -- Sound length (R/W)
; --
; -- Bit 7-0 - Sound length
; --
rNR31 EQU $FF1B
rAUD3LEN EQU rNR31
; --
; -- AUD3LEVEL/NR32 ($FF1C)
; -- Select output level
; --
; -- Bit 6-5 - Select output level
; -- 00: 0/1 (mute)
; -- 01: 1/1
; -- 10: 1/2
; -- 11: 1/4
; --
rNR32 EQU $FF1C
rAUD3LEVEL EQU rNR32
; --
; -- AUD3LOW/NR33 ($FF1D)
; -- Frequency low byte (W)
; --
; -- see AUD1LOW for info
; --
rNR33 EQU $FF1D
rAUD3LOW EQU rNR33
; --
; -- AUD3HIGH/NR34 ($FF1E)
; -- Frequency high byte (W)
; --
; -- see AUD1HIGH for info
; --
rNR34 EQU $FF1E
rAUD3HIGH EQU rNR34
; --
; -- AUD4LEN/NR41 ($FF20)
; -- Sound length (R/W)
; --
; -- Bit 5-0 - Sound length data (# 0-63)
; --
rNR41 EQU $FF20
rAUD4LEN EQU rNR41
; --
; -- AUD4ENV/NR42 ($FF21)
; -- Envelope (R/W)
; --
; -- see AUD1ENV for info
; --
rNR42 EQU $FF21
rAUD4ENV EQU rNR42
; --
; -- AUD4POLY/NR43 ($FF22)
; -- Polynomial counter (R/W)
; --
; -- Bit 7-4 - Selection of the shift clock frequency of the (scf)
; -- polynomial counter (0000-1101)
; -- freq=drf*1/2^scf (not sure)
; -- Bit 3 - Selection of the polynomial counter's step
; -- 0: 15 steps
; -- 1: 7 steps
; -- Bit 2-0 - Selection of the dividing ratio of frequencies (drf)
; -- 000: f/4 001: f/8 010: f/16 011: f/24
; -- 100: f/32 101: f/40 110: f/48 111: f/56 (f=4.194304 Mhz)
; --
rNR43 EQU $FF22
rAUD4POLY EQU rNR43
; --
; -- AUD4GO/NR44 ($FF23)
; --
; -- Bit 7 - Inital
; -- Bit 6 - Counter/consecutive selection
; --
rNR44 EQU $FF23
rAUD4GO EQU rNR44
; --
; -- AUDVOL/NR50 ($FF24)
; -- Channel control / ON-OFF / Volume (R/W)
; --
; -- Bit 7 - Vin->SO2 ON/OFF (Vin??)
; -- Bit 6-4 - SO2 output level (volume) (# 0-7)
; -- Bit 3 - Vin->SO1 ON/OFF (Vin??)
; -- Bit 2-0 - SO1 output level (volume) (# 0-7)
; --
rNR50 EQU $FF24
rAUDVOL EQU rNR50
AUDVOL_VIN_LEFT EQU %10000000 ; SO2
AUDVOL_VIN_RIGHT EQU %00001000 ; SO1
; --
; -- AUDTERM/NR51 ($FF25)
; -- Selection of Sound output terminal (R/W)
; --
; -- Bit 7 - Output sound 4 to SO2 terminal
; -- Bit 6 - Output sound 3 to SO2 terminal
; -- Bit 5 - Output sound 2 to SO2 terminal
; -- Bit 4 - Output sound 1 to SO2 terminal
; -- Bit 3 - Output sound 4 to SO1 terminal
; -- Bit 2 - Output sound 3 to SO1 terminal
; -- Bit 1 - Output sound 2 to SO1 terminal
; -- Bit 0 - Output sound 0 to SO1 terminal
; --
rNR51 EQU $FF25
rAUDTERM EQU rNR51
; SO2
AUDTERM_4_LEFT EQU %10000000
AUDTERM_3_LEFT EQU %01000000
AUDTERM_2_LEFT EQU %00100000
AUDTERM_1_LEFT EQU %00010000
; SO1
AUDTERM_4_RIGHT EQU %00001000
AUDTERM_3_RIGHT EQU %00000100
AUDTERM_2_RIGHT EQU %00000010
AUDTERM_1_RIGHT EQU %00000001
; --
; -- AUDENA/NR52 ($FF26)
; -- Sound on/off (R/W)
; --
; -- Bit 7 - All sound on/off (sets all audio regs to 0!)
; -- Bit 3 - Sound 4 ON flag (read only)
; -- Bit 2 - Sound 3 ON flag (read only)
; -- Bit 1 - Sound 2 ON flag (read only)
; -- Bit 0 - Sound 1 ON flag (read only)
; --
rNR52 EQU $FF26
rAUDENA EQU rNR52
AUDENA_ON EQU %10000000
AUDENA_OFF EQU %00000000 ; sets all audio regs to 0!
; --
; -- LCDC ($FF40)
; -- LCD Control (R/W)
; --
rLCDC EQU $FF40
LCDCF_OFF EQU %00000000 ; LCD Control Operation
LCDCF_ON EQU %10000000 ; LCD Control Operation
LCDCF_WIN9800 EQU %00000000 ; Window Tile Map Display Select
LCDCF_WIN9C00 EQU %01000000 ; Window Tile Map Display Select
LCDCF_WINOFF EQU %00000000 ; Window Display
LCDCF_WINON EQU %00100000 ; Window Display
LCDCF_BG8800 EQU %00000000 ; BG & Window Tile Data Select
LCDCF_BG8000 EQU %00010000 ; BG & Window Tile Data Select
LCDCF_BG9800 EQU %00000000 ; BG Tile Map Display Select
LCDCF_BG9C00 EQU %00001000 ; BG Tile Map Display Select
LCDCF_OBJ8 EQU %00000000 ; OBJ Construction
LCDCF_OBJ16 EQU %00000100 ; OBJ Construction
LCDCF_OBJOFF EQU %00000000 ; OBJ Display
LCDCF_OBJON EQU %00000010 ; OBJ Display
LCDCF_BGOFF EQU %00000000 ; BG Display
LCDCF_BGON EQU %00000001 ; BG Display
; "Window Character Data Select" follows BG
; --
; -- STAT ($FF41)
; -- LCDC Status (R/W)
; --
rSTAT EQU $FF41
STATF_LYC EQU %01000000 ; LYC=LY Coincidence (Selectable)
STATF_MODE10 EQU %00100000 ; Mode 10
STATF_MODE01 EQU %00010000 ; Mode 01 (V-Blank)
STATF_MODE00 EQU %00001000 ; Mode 00 (H-Blank)
STATF_LYCF EQU %00000100 ; Coincidence Flag
STATF_HBL EQU %00000000 ; H-Blank
STATF_VBL EQU %00000001 ; V-Blank
STATF_OAM EQU %00000010 ; OAM-RAM is used by system
STATF_LCD EQU %00000011 ; Both OAM and VRAM used by system
STATF_BUSY EQU %00000010 ; When set, VRAM access is unsafe
; --
; -- SCY ($FF42)
; -- Scroll Y (R/W)
; --
rSCY EQU $FF42
; --
; -- SCX ($FF43)
; -- Scroll X (R/W)
; --
rSCX EQU $FF43
; --
; -- LY ($FF44)
; -- LCDC Y-Coordinate (R)
; --
; -- Values range from 0->153. 144->153 is the VBlank period.
; --
rLY EQU $FF44
; --
; -- LYC ($FF45)
; -- LY Compare (R/W)
; --
; -- When LY==LYC, STATF_LYCF will be set in STAT
; --
rLYC EQU $FF45
; --
; -- DMA ($FF46)
; -- DMA Transfer and Start Address (W)
; --
rDMA EQU $FF46
; --
; -- BGP ($FF47)
; -- BG Palette Data (W)
; --
; -- Bit 7-6 - Intensity for %11
; -- Bit 5-4 - Intensity for %10
; -- Bit 3-2 - Intensity for %01
; -- Bit 1-0 - Intensity for %00
; --
rBGP EQU $FF47
; --
; -- OBP0 ($FF48)
; -- Object Palette 0 Data (W)
; --
; -- See BGP for info
; --
rOBP0 EQU $FF48
; --
; -- OBP1 ($FF49)
; -- Object Palette 1 Data (W)
; --
; -- See BGP for info
; --
rOBP1 EQU $FF49
; --
; -- WY ($FF4A)
; -- Window Y Position (R/W)
; --
; -- 0 <= WY <= 143
; -- When WY = 0, the window is displayed from the top edge of the LCD screen.
; --
rWY EQU $FF4A
; --
; -- WX ($FF4B)
; -- Window X Position (R/W)
; --
; -- 7 <= WX <= 166
; -- When WX = 7, the window is displayed from the left edge of the LCD screen.
; -- Values of 0-6 and 166 are unreliable due to hardware bugs.
; --
rWX EQU $FF4B
; --
; -- SPEED ($FF4D)
; -- Select CPU Speed (R/W)
; --
rKEY1 EQU $FF4D
rSPD EQU rKEY1
KEY1F_DBLSPEED EQU %10000000 ; 0=Normal Speed, 1=Double Speed (R)
KEY1F_PREPARE EQU %00000001 ; 0=No, 1=Prepare (R/W)
; --
; -- VBK ($FF4F)
; -- Select Video RAM Bank (R/W)
; --
; -- Bit 0 - Bank Specification (0: Specify Bank 0; 1: Specify Bank 1)
; --
rVBK EQU $FF4F
; --
; -- HDMA1 ($FF51)
; -- High byte for Horizontal Blanking/General Purpose DMA source address (W)
; -- CGB Mode Only
; --
rHDMA1 EQU $FF51
; --
; -- HDMA2 ($FF52)
; -- Low byte for Horizontal Blanking/General Purpose DMA source address (W)
; -- CGB Mode Only
; --
rHDMA2 EQU $FF52
; --
; -- HDMA3 ($FF53)
; -- High byte for Horizontal Blanking/General Purpose DMA destination address (W)
; -- CGB Mode Only
; --
rHDMA3 EQU $FF53
; --
; -- HDMA4 ($FF54)
; -- Low byte for Horizontal Blanking/General Purpose DMA destination address (W)
; -- CGB Mode Only
; --
rHDMA4 EQU $FF54
; --
; -- HDMA5 ($FF55)
; -- Transfer length (in tiles minus 1)/mode/start for Horizontal Blanking, General Purpose DMA (R/W)
; -- CGB Mode Only
; --
rHDMA5 EQU $FF55
HDMA5F_MODE_GP EQU %00000000 ; General Purpose DMA (W)
HDMA5F_MODE_HBL EQU %10000000 ; HBlank DMA (W)
; -- Once DMA has started, use HDMA5F_BUSY to check when the transfer is complete
HDMA5F_BUSY EQU %10000000 ; 0=Busy (DMA still in progress), 1=Transfer complete (R)
; --
; -- RP ($FF56)
; -- Infrared Communications Port (R/W)
; -- CGB Mode Only
; --
rRP EQU $FF56
RPF_ENREAD EQU %11000000
RPF_DATAIN EQU %00000010 ; 0=Receiving IR Signal, 1=Normal
RPF_WRITE_HI EQU %00000001
RPF_WRITE_LO EQU %00000000
; --
; -- BCPS ($FF68)
; -- Background Color Palette Specification (R/W)
; --
rBCPS EQU $FF68
BCPSF_AUTOINC EQU %10000000 ; Auto Increment (0=Disabled, 1=Increment after Writing)
; --
; -- BCPD ($FF69)
; -- Background Color Palette Data (R/W)
; --
rBCPD EQU $FF69
; --
; -- OCPS ($FF6A)
; -- Object Color Palette Specification (R/W)
; --
rOCPS EQU $FF6A
OCPSF_AUTOINC EQU %10000000 ; Auto Increment (0=Disabled, 1=Increment after Writing)
; --
; -- OCPD ($FF6B)
; -- Object Color Palette Data (R/W)
; --
rOCPD EQU $FF6B
; --
; -- SMBK/SVBK ($FF70)
; -- Select Main RAM Bank (R/W)
; --
; -- Bit 2-0 - Bank Specification (0,1: Specify Bank 1; 2-7: Specify Banks 2-7)
; --
rSVBK EQU $FF70
rSMBK EQU rSVBK
; --
; -- PCM12 ($FF76)
; -- Sound channel 1&2 PCM amplitude (R)
; --
; -- Bit 7-4 - Copy of sound channel 2's PCM amplitude
; -- Bit 3-0 - Copy of sound channel 1's PCM amplitude
; --
rPCM12 EQU $FF76
; --
; -- PCM34 ($FF77)
; -- Sound channel 3&4 PCM amplitude (R)
; --
; -- Bit 7-4 - Copy of sound channel 4's PCM amplitude
; -- Bit 3-0 - Copy of sound channel 3's PCM amplitude
; --
rPCM34 EQU $FF77
; --
; -- IE ($FFFF)
; -- Interrupt Enable (R/W)
; --
rIE EQU $FFFF
IEF_HILO EQU %00010000 ; Transition from High to Low of Pin number P10-P13
IEF_SERIAL EQU %00001000 ; Serial I/O transfer end
IEF_TIMER EQU %00000100 ; Timer Overflow
IEF_LCDC EQU %00000010 ; LCDC (see STAT)
IEF_VBLANK EQU %00000001 ; V-Blank
;***************************************************************************
;*
;* Flags common to multiple sound channels
;*
;***************************************************************************
; --
; -- Square wave duty cycle
; --
; -- Can be used with AUD1LEN and AUD2LEN
; -- See AUD1LEN for more info
; --
AUDLEN_DUTY_12_5 EQU %00000000 ; 12.5%
AUDLEN_DUTY_25 EQU %01000000 ; 25%
AUDLEN_DUTY_50 EQU %10000000 ; 50%
AUDLEN_DUTY_75 EQU %11000000 ; 75%
; --
; -- Audio envelope flags
; --
; -- Can be used with AUD1ENV, AUD2ENV, AUD4ENV
; -- See AUD1ENV for more info
; --
AUDENV_UP EQU %00001000
AUDENV_DOWN EQU %00000000
; --
; -- Audio trigger flags
; --
; -- Can be used with AUD1HIGH, AUD2HIGH, AUD3HIGH
; -- See AUD1HIGH for more info
; --
AUDHIGH_RESTART EQU %10000000
AUDHIGH_LENGTH_ON EQU %01000000
AUDHIGH_LENGTH_OFF EQU %00000000
;***************************************************************************
;*
;* CPU values on bootup (a=type, b=qualifier)
;*
;***************************************************************************
BOOTUP_A_DMG EQU $01 ; Dot Matrix Game
BOOTUP_A_CGB EQU $11 ; Color GameBoy
BOOTUP_A_MGB EQU $FF ; Mini GameBoy (Pocket GameBoy)
; if a=BOOTUP_A_CGB, bit 0 in b can be checked to determine if real CGB or
; other system running in GBC mode
BOOTUP_B_CGB EQU %00000000
BOOTUP_B_AGB EQU %00000001 ; GBA, GBA SP, Game Boy Player, or New GBA SP
;***************************************************************************
;*
;* Cart related
;*
;***************************************************************************
; $0143 Color GameBoy compatibility code
CART_COMPATIBLE_DMG EQU $00
CART_COMPATIBLE_DMG_GBC EQU $80
CART_COMPATIBLE_GBC EQU $C0
; $0146 GameBoy/Super GameBoy indicator
CART_INDICATOR_GB EQU $00
CART_INDICATOR_SGB EQU $03
; $0147 Cartridge type
CART_ROM EQU $00
CART_ROM_MBC1 EQU $01
CART_ROM_MBC1_RAM EQU $02
CART_ROM_MBC1_RAM_BAT EQU $03
CART_ROM_MBC2 EQU $05
CART_ROM_MBC2_BAT EQU $06
CART_ROM_RAM EQU $08
CART_ROM_RAM_BAT EQU $09
CART_ROM_MMM01 EQU $0B
CART_ROM_MMM01_RAM EQU $0C
CART_ROM_MMM01_RAM_BAT EQU $0D
CART_ROM_MBC3_BAT_RTC EQU $0F
CART_ROM_MBC3_RAM_BAT_RTC EQU $10
CART_ROM_MBC3 EQU $11
CART_ROM_MBC3_RAM EQU $12
CART_ROM_MBC3_RAM_BAT EQU $13
CART_ROM_MBC5 EQU $19
CART_ROM_MBC5_BAT EQU $1A
CART_ROM_MBC5_RAM_BAT EQU $1B
CART_ROM_MBC5_RUMBLE EQU $1C
CART_ROM_MBC5_RAM_RUMBLE EQU $1D
CART_ROM_MBC5_RAM_BAT_RUMBLE EQU $1E
CART_ROM_MBC7_RAM_BAT_GYRO EQU $22
CART_ROM_POCKET_CAMERA EQU $FC
CART_ROM_BANDAI_TAMA5 EQU $FD
CART_ROM_HUDSON_HUC3 EQU $FE
CART_ROM_HUDSON_HUC1 EQU $FF
; $0148 ROM size
; these are kilobytes
CART_ROM_32KB EQU $00 ; 2 banks
CART_ROM_64KB EQU $01 ; 4 banks
CART_ROM_128KB EQU $02 ; 8 banks
CART_ROM_256KB EQU $03 ; 16 banks
CART_ROM_512KB EQU $04 ; 32 banks
CART_ROM_1024KB EQU $05 ; 64 banks
CART_ROM_2048KB EQU $06 ; 128 banks
CART_ROM_4096KB EQU $07 ; 256 banks
CART_ROM_8192KB EQU $08 ; 512 banks
CART_ROM_1152KB EQU $52 ; 72 banks
CART_ROM_1280KB EQU $53 ; 80 banks
CART_ROM_1536KB EQU $54 ; 96 banks
; $0149 SRAM size
; these are kilobytes
CART_SRAM_NONE EQU 0
CART_SRAM_2KB EQU 1 ; 1 incomplete bank
CART_SRAM_8KB EQU 2 ; 1 bank
CART_SRAM_32KB EQU 3 ; 4 banks
CART_SRAM_128KB EQU 4 ; 16 banks
CART_SRAM_ENABLE EQU $0A
CART_SRAM_DISABLE EQU $00
; $014A Destination code
CART_DEST_JAPANESE EQU $00
CART_DEST_NON_JAPANESE EQU $01
;***************************************************************************
;*
;* Keypad related
;*
;***************************************************************************
PADF_DOWN EQU $80
PADF_UP EQU $40
PADF_LEFT EQU $20
PADF_RIGHT EQU $10
PADF_START EQU $08
PADF_SELECT EQU $04
PADF_B EQU $02
PADF_A EQU $01
PADB_DOWN EQU $7
PADB_UP EQU $6
PADB_LEFT EQU $5
PADB_RIGHT EQU $4
PADB_START EQU $3
PADB_SELECT EQU $2
PADB_B EQU $1
PADB_A EQU $0
;***************************************************************************
;*
;* Screen related
;*
;***************************************************************************
SCRN_X EQU 160 ; Width of screen in pixels
SCRN_Y EQU 144 ; Height of screen in pixels
SCRN_X_B EQU 20 ; Width of screen in bytes
SCRN_Y_B EQU 18 ; Height of screen in bytes
SCRN_VX EQU 256 ; Virtual width of screen in pixels
SCRN_VY EQU 256 ; Virtual height of screen in pixels
SCRN_VX_B EQU 32 ; Virtual width of screen in bytes
SCRN_VY_B EQU 32 ; Virtual height of screen in bytes
;***************************************************************************
;*
;* OAM related
;*
;***************************************************************************
; OAM attributes
; each entry in OAM RAM is 4 bytes (sizeof_OAM_ATTRS)
RSRESET
OAMA_Y RB 1 ; y pos
OAMA_X RB 1 ; x pos
OAMA_TILEID RB 1 ; tile id
OAMA_FLAGS RB 1 ; flags (see below)
sizeof_OAM_ATTRS RB 0
OAM_COUNT EQU 40 ; number of OAM entries in OAM RAM
; flags
OAMF_PRI EQU %10000000 ; Priority
OAMF_YFLIP EQU %01000000 ; Y flip
OAMF_XFLIP EQU %00100000 ; X flip
OAMF_PAL0 EQU %00000000 ; Palette number; 0,1 (DMG)
OAMF_PAL1 EQU %00010000 ; Palette number; 0,1 (DMG)
OAMF_BANK0 EQU %00000000 ; Bank number; 0,1 (GBC)
OAMF_BANK1 EQU %00001000 ; Bank number; 0,1 (GBC)
OAMF_PALMASK EQU %00000111 ; Palette (GBC)
OAMB_PRI EQU 7 ; Priority
OAMB_YFLIP EQU 6 ; Y flip
OAMB_XFLIP EQU 5 ; X flip
OAMB_PAL1 EQU 4 ; Palette number; 0,1 (DMG)
OAMB_BANK1 EQU 3 ; Bank number; 0,1 (GBC)
;*
;* Nintendo scrolling logo
;* (Code won't work on a real GameBoy)
;* (if next lines are altered.)
NINTENDO_LOGO : MACRO
DB $CE,$ED,$66,$66,$CC,$0D,$00,$0B,$03,$73,$00,$83,$00,$0C,$00,$0D
DB $00,$08,$11,$1F,$88,$89,$00,$0E,$DC,$CC,$6E,$E6,$DD,$DD,$D9,$99
DB $BB,$BB,$67,$63,$6E,$0E,$EC,$CC,$DD,$DC,$99,$9F,$BB,$B9,$33,$3E
ENDM
ENDC ;HARDWARE_INC

731
code/main.asm

@ -0,0 +1,731 @@
include "hardware.inc"
include "constants.inc"
include "signals.asm"
include "ops.asm"
include "tick.asm"
; --------------------------------------------------------------------------------------------------------------------
; Interrupt Vectors
; --------------------------------------------------------------------------------------------------------------------
SECTION "Vblank", ROM0[$0040]
jp UpdateTiles
SECTION "LCDC", ROM0[$0048]
reti
SECTION "Timer", ROM0[$0050]
jp Timer
SECTION "Serial", ROM0[$0058]
reti
SECTION "Joypad", ROM0[$0060]
reti
; Entry point
SECTION "Entry", ROM0[$100]
nop
jp start
; --------------------------------------------------------------------------------------------------------------------
; Header
; --------------------------------------------------------------------------------------------------------------------
SECTION "Header",ROM0[$0104]
; Logo
DB $CE,$ED,$66,$66,$CC,$0D,$00,$0B,$03,$73,$00,$83,$00,$0C,$00,$0D
DB $00,$08,$11,$1F,$88,$89,$00,$0E,$DC,$CC,$6E,$E6,$DD,$DD,$D9,$99
DB $BB,$BB,$67,$63,$6E,$0E,$EC,$CC,$DD,$DC,$99,$9F,$BB,$B9,$33,$3E
; ROM Details
DB "8BIT00000000000" ; $134 - Title (exactly 15 characters)
DB 0 ; $143 - GBC Functionality: No
DB 0,0 ; $144 - Licensee code
DB 0 ; $146 - SGB Support: No
DB 0 ; $147 - Cart type: No MBC (32K ROM only)
DB 0 ; $148 - ROM Size: 32K (No Banking)
DB 0 ; $149 - External ram Size: None
DB 1 ; $14a - Destination: Non-Japan
DB $33 ; $14b - Old Licensee code: must be $33
DB 0 ; $14c - Mask ROM version
DB 0 ; $14d - Complement check (RGBDS will fill)
DW 0 ; $14e - Checksum (RGBDS will fill)
; --------------------------------------------------------------------------------------------------------------------
; Entry Point
; --------------------------------------------------------------------------------------------------------------------
SECTION "Main", ROM0[$150]
start:
di
ld SP, $FFFF
; Turn LCD off
.wait_for_vblank
ldh a, [rLY]
cp 145
jr nz, .wait_for_vblank
ld a, [rLCDC]
xor LCDCF_ON
ld [rLCDC], a
; Load tiles into VRAM
ld hl, _VRAM
ld de, Tiles_Begin
ld bc, Tiles_End-Tiles_Begin
call CopyBytes
; Fill the map
ld hl, _SCRN0
ld de, TileMap_Begin
ld bc, TileMap_End-TileMap_Begin
call CopyBytes
; Set background palette
ld a, %11100100
ld [rBGP], a
; Turn LCD back on
ld a, [rLCDC]
or LCDCF_ON
ld [rLCDC], a
; Set up timer and vblank interrupts
ld a, IEF_TIMER | IEF_VBLANK
ld [rIE], a
; Configure timer
; TODO: Make this adjustable at runtime (clock speed adjust)
ld a, TACF_4KHZ | TACF_START
ld [rTAC], a
xor a
ld [rTMA], a
; Zero all state
ld hl, StateBegin
ld bc, StateEnd-StateBegin
call SetByte
; Zero all values
ld hl, DataBegin
ld bc, DataEnd-DataBegin
call SetByte
; Turn off all LEDs
ld a, LED_OFF
ld hl, LedBegin
ld bc, LedEnd-LedBegin
call SetByte
; Load the program
; TODO: Make this programmable at runtime
ld a, $e0
ld [ram], a ; OUT
ld a, $2f
ld [ram+1], a ; ADD 15
ld a, $74
ld [ram+2], a ; JC 4
ld a, $60
ld [ram+3], a ; JMP 0
ld a, $3f
ld [ram+4], a ; SUB 15
ld a, $e0
ld [ram+5], a ; OUT
ld a, $80
ld [ram+6], a ; JZ 0
ld a, $64
ld [ram+7], a ; JMP 4
xor a
ld [ram+8], a ; NOP
ld [ram+9], a ; NOP
ld [ram+10], a ; NOP
ld [ram+11], a ; NOP
ld [ram+12], a ; NOP
ld [ram+13], a ; NOP
ld [ram+14], a ; NOP
ld a, 15
ld [ram+15], a ; Data
; Load default clock of 1Hz (16 timer interrupts)
ld a, 2
ld [clk], a
ld a, 1
ld [clk_div2], a
; Initialize as running
ld a, 1
ld [running], a
; Tick once before we begin to set the stage
call Tick
ei
.loop
halt
nop
; If we aren't running, loop
ld a, [running]
cp 1
jr nz, .loop
; Check for Button A state
; State is only set once per press; no repeats
call ReadKeys
bit 0, a
jr z, .key_released
.key_pressed:
ld a, LED_ON
ld [clk_led], a
ld a, [button_state]
cp 0
jr z, .tick
jr .loop
.key_released:
xor a
ld [button_state], a
ld a, LED_OFF
ld [clk_led], a
jr .loop
.tick:
; Key press = rising edge
; Key release = falling edge
ld a, 1
ld [button_state], a
call Tick
jr .loop
; [in] de: Source address
; [in] hl: Destination address
; [in] bc: Count
CopyBytes:
; Increment each by one to prevent rolling over when decrementing
inc b
inc c
jr .skip
.loop:
ld a, [de]
ld [hl+], a
inc de
.skip:
dec c
jr nz, .loop
dec b
jr nz, .loop
ret
; [in] a: Byte to set
; [in] hl: Destination address
; [in] bc: Count
SetByte:
; Increment each by one to prevent rolling over when decrementing
inc b
inc c
jr .skip
.loop
ld [hl+], a
.skip:
dec c
jr nz, .loop
dec b
jr nz, .loop
ret
; [out] a: x x x x start select b a
ReadKeys:
ld a, P1F_GET_BTN ;
ld [rP1], a ; joypad info
ld a, [rP1] ;
ld a, [rP1] ; read twice to make sure
and $0f ; low nibble contains buttons
cpl ; low means pressed so we complement for logic purposes
ret
SECTION "Handlers", ROM0
Timer:
push af
ld a, [w_counter]
add a, 1
ld [w_counter], a
ld hl, clk_div2
cp [hl]
jr z, .rising_edge
ld hl, clk
cp [hl]
jr z, .falling_edge
jr .exit
.rising_edge:
ld a, LED_ON
ld [clk_led], a
call Tick
jr .exit
.falling_edge:
ld a, LED_OFF
ld [clk_led], a
xor a
ld [w_counter], a
.exit:
pop af
reti
UpdateTiles:
push af
; CLK
ld hl, _SCRN0 + 4
ld a, [clk_led]
ld [hl], a
; PC
ld hl, _SCRN0 + 13
ld a, [pc_led_3]
ld [hl+], a
ld a, [pc_led_2]
ld [hl+], a
ld a, [pc_led_1]
ld [hl+], a
ld a, [pc_led_0]
ld [hl], a
; OP
ld hl, _SCRN0 + $040 + 14
ld a, [opc_led_2]
ld [hl+], a
ld a, [opc_led_1]
ld [hl+], a
ld a, [opc_led_0]
ld [hl], a
; IR
ld hl, _SCRN0 + $040 + 4
ld a, [ir_led_7]
ld [hl+], a
ld a, [ir_led_6]
ld [hl+], a
ld a, [ir_led_5]
ld [hl+], a
ld a, [ir_led_4]
ld [hl+], a
ld a, [ir_led_3]
ld [hl+], a
ld a, [ir_led_2]
ld [hl+], a
ld a, [ir_led_1]
ld [hl+], a
ld a, [ir_led_0]
ld [hl], a
; MAR
ld hl, _SCRN0 + $080 + 4
ld a, [mar_led_3]
ld [hl+], a
ld a, [mar_led_2]
ld [hl+], a
ld a, [mar_led_1]
ld [hl+], a
ld a, [mar_led_0]
ld [hl], a
; BUS
ld hl, _SCRN0 + $0A0 + 4
ld a, [mem_led_7]
ld [hl+], a
ld a, [mem_led_6]
ld [hl+], a
ld a, [mem_led_5]
ld [hl+], a
ld a, [mem_led_4]
ld [hl+], a
ld a, [mem_led_3]
ld [hl+], a
ld a, [mem_led_2]
ld [hl+], a
ld a, [mem_led_1]
ld [hl+], a
ld a, [mem_led_0]
ld [hl], a
; BUS
ld hl, _SCRN0 + $0E0 + 4
ld a, [bus_led_7]
ld [hl+], a
ld a, [bus_led_6]
ld [hl+], a
ld a, [bus_led_5]
ld [hl+], a
ld a, [bus_led_4]
ld [hl+], a
ld a, [bus_led_3]
ld [hl+], a
ld a, [bus_led_2]
ld [hl+], a
ld a, [bus_led_1]
ld [hl+], a
ld a, [bus_led_0]
ld [hl], a
; A
ld hl, _SCRN0 + $120 + 4
ld a, [a_led_7]
ld [hl+], a
ld a, [a_led_6]
ld [hl+], a
ld a, [a_led_5]
ld [hl+], a
ld a, [a_led_4]
ld [hl+], a
ld a, [a_led_3]
ld [hl+], a
ld a, [a_led_2]
ld [hl+], a
ld a, [a_led_1]
ld [hl+], a
ld a, [a_led_0]
ld [hl], a
; B
ld hl, _SCRN0 + $140 + 4
ld a, [b_led_7]
ld [hl+], a
ld a, [b_led_6]
ld [hl+], a
ld a, [b_led_5]
ld [hl+], a
ld a, [b_led_4]
ld [hl+], a
ld a, [b_led_3]
ld [hl+], a
ld a, [b_led_2]
ld [hl+], a
ld a, [b_led_1]
ld [hl+], a
ld a, [b_led_0]
ld [hl], a
; ALU
ld hl, _SCRN0 + $160 + 4
ld a, [alu_led_7]
ld [hl+], a
ld a, [alu_led_6]
ld [hl+], a
ld a, [alu_led_5]
ld [hl+], a
ld a, [alu_led_4]
ld [hl+], a
ld a, [alu_led_3]
ld [hl+], a
ld a, [alu_led_2]
ld [hl+], a
ld a, [alu_led_1]
ld [hl+], a
ld a, [alu_led_0]
ld [hl], a
; CTRL
ld hl, _SCRN0 + $1A0 + 4
ld a, [ctrl_led_ht]
ld [hl+], a
ld a, [ctrl_led_mi]
ld [hl+], a
ld a, [ctrl_led_ri]
ld [hl+], a
ld a, [ctrl_led_ro]
ld [hl+], a
ld a, [ctrl_led_io]
ld [hl+], a
ld a, [ctrl_led_ii]
ld [hl+], a
ld a, [ctrl_led_ai]
ld [hl+], a
ld a, [ctrl_led_ao]
ld [hl+], a
ld a, [ctrl_led_eo]
ld [hl+], a
ld a, [ctrl_led_su]
ld [hl+], a
ld a, [ctrl_led_bi]
ld [hl+], a
ld a, [ctrl_led_oi]
ld [hl+], a
ld a, [ctrl_led_ce]
ld [hl+], a
ld a, [ctrl_led_co]
ld [hl+], a
ld a, [ctrl_led_jp]
ld [hl+], a
ld a, [ctrl_led_fi]
ld [hl], a
; Flags
ld hl, _SCRN0 + $160 + 13
ld a, [flag_led_c]
ld [hl+], a
ld a, [flag_led_z]
ld [hl], a
; OUT
ld hl, _SCRN0 + $220 + 4
; 100s
ld a, [display]
add a, $1 ; $1 = tile id of 0
ld [hl+], a
; 10s
ld a, [display+1]
add a, $1
ld [hl+], a
; 1s
ld a, [display+2]
add a, $1
ld [hl], a
.exit
pop af
reti
; --------------------------------------------------------------------------------------------------------------------
; Tile Data
; --------------------------------------------------------------------------------------------------------------------
SECTION "Tile Data", ROM0
Tiles_Begin:
DB $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF ; Blank ($00)
DB $83,$83,$7D,$7D,$6D,$6D,$6D,$6D,$6D,$6D,$7D,$7D,$83,$83,$FF,$FF ; 0 ($01)
DB $EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$FF,$FF ; 1 ($02)
DB $07,$07,$FB,$FB,$FB,$FB,$87,$87,$7F,$7F,$7F,$7F,$03,$03,$FF,$FF ; 2 ($03)
DB $03,$03,$FD,$FD,$FD,$FD,$83,$83,$FD,$FD,$FD,$FD,$03,$03,$FF,$FF ; 3 ($04)
DB $7D,$7D,$7D,$7D,$7D,$7D,$81,$81,$FD,$FD,$FD,$FD,$FD,$FD,$FF,$FF ; 4 ($05)
DB $03,$03,$7F,$7F,$7F,$7F,$07,$07,$FB,$FB,$FB,$FB,$07,$07,$FF,$FF ; 5 ($06)
DB $83,$83,$7F,$7F,$7F,$7F,$03,$03,$7D,$7D,$7D,$7D,$83,$83,$FF,$FF ; 6 ($07)
DB $01,$01,$FD,$FD,$FD,$FD,$FD,$FD,$FD,$FD,$FD,$FD,$FD,$FD,$FF,$FF ; 7 ($08)
DB $83,$83,$7D,$7D,$7D,$7D,$83,$83,$7D,$7D,$7D,$7D,$83,$83,$FF,$FF ; 8 ($09)
DB $83,$83,$7D,$7D,$7D,$7D,$81,$81,$FD,$FD,$FD,$FD,$FD,$FD,$FF,$FF ; 9 ($0A)
DB $C7,$C7,$BB,$BB,$7D,$7D,$7D,$7D,$01,$01,$7D,$7D,$7D,$7D,$FF,$FF ; A ($0B)
DB $03,$03,$7D,$7D,$7D,$7D,$03,$03,$7D,$7D,$7D,$7D,$03,$03,$FF,$FF ; B ($0C)
DB $83,$83,$7D,$7D,$7F,$7F,$7F,$7F,$7F,$7F,$7D,$7D,$83,$83,$FF,$FF ; C ($0D)
DB $03,$03,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$03,$03,$FF,$FF ; D ($0E)
DB $83,$83,$7F,$7F,$7F,$7F,$07,$07,$7F,$7F,$7F,$7F,$83,$83,$FF,$FF ; E ($0F)
DB $01,$01,$7F,$7F,$7F,$7F,$03,$03,$7F,$7F,$7F,$7F,$7F,$7F,$FF,$FF ; F ($10)
DB $83,$83,$7D,$7D,$7F,$7F,$61,$61,$7D,$7D,$7D,$7D,$83,$83,$FF,$FF ; G ($11)
DB $7D,$7D,$7D,$7D,$7D,$7D,$01,$01,$7D,$7D,$7D,$7D,$7D,$7D,$FF,$FF ; H ($12)
DB $01,$01,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$01,$01,$FF,$FF ; I ($13)
DB $01,$01,$F7,$F7,$F7,$F7,$F7,$F7,$77,$77,$77,$77,$8F,$8F,$FF,$FF ; J ($14)
DB $7B,$7B,$7B,$7B,$7B,$7B,$07,$07,$7B,$7B,$7B,$7B,$7B,$7B,$FF,$FF ; K ($15)
DB $7F,$7F,$7F,$7F,$7F,$7F,$7F,$7F,$7F,$7F,$7F,$7F,$03,$03,$FF,$FF ; L ($16)
DB $BB,$BB,$55,$55,$6D,$6D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$FF,$FF ; M ($17)
DB $03,$03,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$FF,$FF ; N ($18)
DB $83,$83,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$83,$83,$FF,$FF ; O ($19)
DB $03,$03,$7D,$7D,$7D,$7D,$03,$03,$7F,$7F,$7F,$7F,$7F,$7F,$FF,$FF ; P ($1A)
DB $83,$83,$7D,$7D,$7D,$7D,$7D,$7D,$75,$75,$7B,$7B,$85,$85,$FF,$FF ; Q ($1B)
DB $83,$83,$7D,$7D,$7D,$7D,$03,$03,$7D,$7D,$7D,$7D,$7D,$7D,$FF,$FF ; R ($1C)
DB $81,$81,$7F,$7F,$7F,$7F,$83,$83,$FD,$FD,$FD,$FD,$03,$03,$FF,$FF ; S ($1D)
DB $01,$01,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$EF,$FF,$FF ; T ($1E)
DB $7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$83,$83,$FF,$FF ; U ($1F)
DB $7D,$7D,$7D,$7D,$BB,$BB,$BB,$BB,$D7,$D7,$D7,$D7,$EF,$EF,$FF,$FF ; V ($20)
DB $7D,$7D,$7D,$7D,$7D,$7D,$7D,$7D,$6D,$6D,$55,$55,$BB,$BB,$FF,$FF ; W ($21)
DB $7D,$7D,$BB,$BB,$D7,$D7,$EF,$EF,$D7,$D7,$BB,$BB,$7D,$7D,$FF,$FF ; X ($22)
DB $7D,$7D,$7D,$7D,$BB,$BB,$D7,$D7,$EF,$EF,$EF,$EF,$EF,$EF,$FF,$FF ; Y ($23)
DB $01,$01,$FD,$FD,$FB,$FB,$C7,$C7,$BF,$BF,$7F,$7F,$01,$01,$FF,$FF ; Z ($24)
DB $FF,$83,$83,$7D,$83,$7D,$83,$7D,$83,$7D,$83,$7D,$FF,$83,$FF,$FF ; LED Off ($25)
DB $FF,$83,$83,$01,$83,$01,$83,$01,$83,$01,$83,$01,$FF,$83,$FF,$FF ; LED On ($26)
Tiles_End:
; --------------------------------------------------------------------------------------------------------------------
; Tile Map
; --------------------------------------------------------------------------------------------------------------------
SECTION "Tile Map", ROM0
TileMap_Begin:
DB $0D,$16,$15,$00,$25,$00,$00,$00,$00,$00,$00,$00,$00,$25,$25,$25,$25,$00,$1A,$0D, $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; [$000] CLK PC
DB $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; [$020]
DB $00,$13,$1C,$00,$25,$25,$25,$25,$25,$25,$25,$25,$00,$00,$25,$25,$25,$00,$19,$1A, $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; [$040] IR OP
DB $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; [$060]
DB $17,$0B,$1C,$00,$25,$25,$25,$25,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; [$080] MAR
DB $17,$0F,$17,$00,$25,$25,$25,$25,$25,$25,$25,$25,$00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; [$0A0] MEM
DB $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; [$0C0]
DB $0C,$1F,$1D,$00,$25,$25,$25,$25,$25,$25,$25,$25,$00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; [$0E0] BUS
DB $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; [$100]
DB $00,$00,$0B,$00,$25,$25,$25,$25,$25,$25,$25,$25,$00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00