Nichibutsu M68000 (Armed F) FPGA Implementation

FPGA compatible core of Nichibutsu M68000 (Terra Force Based) arcade hardware for MiSTerFPGA written by Darren Olafson. Terra Force PCB (different board revisions) donated by @atrac17 / @djhardrich.

The intent is for this core to be a 1:1 implementation of the Nichibutsu (Terra Force based) 68000 hardware. Currently in an beta state, this core is in active development with assistance from atrac17.

Supported Games

Title	Status	Released	Protection	Unprotected Sets
Terra Force	Implemented	terraf, terrfj, terrafu	NB1414M4	terrafjb, terrafb
Kozure Ōkami	Implemented	kozure	NB1414M4	N/A
Chouji Meikyuu Legion	Implemented	legion, legionj2	NB1414M4	legionjb, legionjb2
Crazy Climber 2	Implemented	cclimbr2, cclimbr2a	NB1414M4	N/A
Armed F	Implemented	armedf, armedff	None	N/A
Tatakae! Big Fighter	Implemented	skyrobo, bigfghtr	i8751	N/A

External Modules

Name	Purpose	Author
fx68k	Motorola 68000 CPU	Jorge Cwik
t80	Zilog Z80 CPU	Daniel Wallner
jtopl2	Yamaha OPL 2	Jose Tejada
jt8751	Intel 8751	Oregano Systems / Jose Tejada
yc_out	Y/C Video Module	Mike Simone

Known Issues / Tasks

• Screen Flip implementation
• Layer priority - Chouji Meikyuu Legion (Japan ver 1.05) [legionj, legionjb]
• Service Menu text layer NB1414M4

PCB Check List

FPGA implementation is based on Terra Force and verified against an authentic Nichibutsu U.S.A Terra Force PCB and bootleg PCB.

Reverse engineering of an authentic Terra Force PCB will be done by Darren Olafson and schematics will be included in the repository.

Clock Information

H-Sync	V-Sync	Source
15.51kHz	59.092993Hz	DSLogic +

Crystal Oscillators

Location	Freq (MHz)	Use
C1 (Top Board)	16.000	M68000
F1 (Bottom Board)	24.000	Z80 / YM3812

Pixel clock: 6.00 MHz

Estimated geometry:

(Terra Force, Kozure Ōkami, Armed F, Tatakae! Big Fighter)

387 pixels/line

262 pixels/line

(Chouji Meikyuu Legion, Crazy Climber 2)

352 pixels/line

248 pixels/line

Main Components

Location	Chip	Use
D1 (Top Board)	Motorola 68000 CPU	Main CPU
H17 (Bottom Board)	Zilog Z80 CPU	Sound CPU
K15 (Bottom Board)	Yamaha YM3812	OPL2
D1 (Daughter Board)	Intel 8751	Protection MCU (Tatakae! Big Fighter)

Nichibutsu Custom Components

Location	Chip	Use	PCB	ROM set
A9 (Top Board)	NB1414M4	Protection IC	Chouji Meikyuu Legion Terra Force Kozure Ōkami Crazy Climber 2	legion, legionj, legionj2 terraf, terrafu, terrafj kozure cclimbr2, cclimbr2a

PCB Features

Debugging Menu

A hidden debug menu can be accessed for all Nichibutsu 68000 (Armed F Based) titles. For more information on each debugging menu per game click here.

Each debug menu has different features to display Character, Object, Scoll, Foreground, Background, Stage Viewer, or Priority tests.

Follow these steps to access the debug menu (OSD or Keyboard):

• Turn on Service Menu in the debug OSD options or press F2. Then turn on Debug Menu or press and hold R, A, S. For Crazy Climber 2 press and hold Up, LCtrl, Spacebar.
  
  
• Toggle the Service Menu option off; then toggle Debug Menu off in the OSD or keep those corresponding keys held and press F2.
  
  Note: Crazy Climber 2 is not accessible in the OSD.
  
  

Character Graphics ROM	Object Graphics ROM	Basic Stage Viewer	Sprite Priority Test

Debugging Features

Chouji Meikyuu Legion	Debugging Features [legion, legionj, legionjb]
	Chouji Meikyuu Legion has hidden debug dipswitches by enabling offsets at 0x000488 and 0x0001d6. Bank 1, switch 8 enables these options on bank 2, switch 7 and 8. This enables P1 and P2 Invunerability and the ability to overclock the games framerate by holding the 2P Start Bttn. The dipswitch information was taken from mame, the overclocked framerate was discovered during core development. These features are enabled in the MRA's for the corresponding sets.
Tatakae! Big Fighter	Debugging Features [skyrobo, bigfghtr]
	There are two dipswitches labeled unused in the in the Tatakae! Big Fighter manual. The dipswitch location for bank 2, switch 6 enables invulnerability and the ability to skip the level by pressing P2 Start Bttn. The dipswitch location on bank 2, switch 8 enables pause in game, this was used for development debugging.

Core Features

Native Y/C Output

• Native Y/C ouput is possible with the analog I/O rev 6.1 pcb. Using the following cables, HD-15 to BNC cable will transmit Y/C over the green and red lines. Choose an appropriate adapter to feed Y/C (S-Video) to your display.

H/V Adjustments

• There are two H/V toggles, H/V-sync positioning adjust and H/V-sync width adjust. Positioning will move the display for centering on CRT display. The sync width adjust can be used to for sync issues (rolling) without modifying the video timings.

Scandoubler Options

• Additional toggle to enable the scandoubler without changing ini settings and new scanline option for 100% is available, this draws a black line every other frame. Below is an example.

Scandoubler Fx	Scanlines 25%	Scanlines 50%	Scanlines 75%	Scanlines 100%

GFX Layer Toggle

• The four graphical layers can be toggled in the OSD under the Debug options or by pressing F7-F10 on the keyboard.

Text Layer	Background Layer	Foreground Layer	Sprite Layer	All Layers

Controls

Game	Joystick	Service Menu	Shared Controls	Dip Default
Armed F	8-Way		Upright	Upright
Chouji Meikyuu Legion	8-Way		Co-Op	Upright
Crazy Climber 2	4-Way		Upright	Upright
Kozure Ōkami	8-Way		Upright	Upright
Terra Force	8-Way		Upright	Upright
Tatakae! Big Fighter	8-Way		Upright	Upright

Note: (Only applies once screen flip is implemented)

Upright cabinets share a 1L3B control panel layout. Players are required to switch controller. If set the cabinet type is set to table, the screen inverts for cocktail mode per player and has multiple controls.

Push button 3 may have no function in game, but corresponds to the original hardware and service menu. Crazy Climber 2 uses two 4-way joysticks and the second stick (right) corresponds to buttons 1 thru 4 for movement.

Keyboard Handler

• Keyboard inputs mapped to mame defaults for all functions.

Services	Coin/Start
Functions Keymap Test F2 Reset F3 Service 9 Pause P	Functions Keymap P1 Start 1 P2 Start 2 P1 Coin 5 P2 Coin 6

Player 1	Player 2
Functions Keymap P1 Up Up P1 Down Down P1 Left Left P1 Right Right P1 Bttn 1 L-Ctrl P1 Bttn 2 L-Alt P1 Bttn 3 Space P1 Bttn 4 L-Shift	Functions Keymap P2 Up R P2 Down F P2 Left D P2 Right G P2 Bttn 1 A P2 Bttn 2 S P2 Bttn 3 Q P2 Bttn 4 W

Debug
Functions Keymap Layer (TXT) F7 Layer (FG) F8 Layer (BG) F9 Layer (SP) F10

Support

Please consider showing support for this and future projects via Darren's Ko-fi and atrac17's Patreon. While it isn't necessary, it's greatly appreciated.

Licensing

Contact the author for special licensing needs. Otherwise follow the GPLv2 license attached.