Ark Area

Ark Area
Developer: UPL Publisher: UPL Platform: Arcade (UPL Ninja-Kid II Hardware) Released in JP: December 1987 This game has uncompiled source code. This game has hidden developer credits. This game has unused graphics.

Ark Area is a shoot 'em up with a manually scrolling playfield and a dedicated turning button. It also has hilariously bad English translation.

Hidden Credits

There are two hidden artist signatures: One is used as filler in the object graphics ROM, while the other is hidden in the background graphics ROM.

The first is "Toriumi", which doesn't match any known UPL employee.

The second is "Noriko", the family name of UPL background designer Noriko Nihei.

(Source: Original TCRF research)

Early Atomic Robo-Kid Graphics

Early
Final

There's an early version of the "Mecha Pochi" enemy from Atomic Robo-Kid in the background graphics ROM. This early design has different "quills", larger eyes, and three different back sprites, none of which match the one used in the final game.

(Source: Original TCRF research)

Full Ending Message

Used	Full

The ending message is slightly longer than what appears on screen; the copyright year is mistakenly placed below the lower camera boundary.

(Source: MAME Ninja-Kid II driver)

Uncompiled Source Code

There are three chunks of uncompiled code used as filler in the audio CPU. Text starts at 0x24EA:

	 D	A,(OPNWRK+40H*5+1BH)
	AND	38H
	OR	B
	OUT	(FM1DAT),A
	RST	WAIT
	LD	A,0A8H
	OUT	(FM1REG),A
	RST	WAIT
	LD	A,(ZZ+1)
	OUT	(FM1DAT),A
	LD	HL,(OPNWRK+40H*5+1AH)
	LD	A,(OPNWRK+40H*5+3FH)
	BIT	3,A
	JR	Z,??40
	LD	HL,(OPNWRK+40H*5+35H)
??40:	LD	A,H
	AND	7
	LD	H,A
	LD	BC,(XX+20H*1+16H)
	CALL	CHGSUB
	LD	A,0A6H
	OUT	(FM1REG),A
	RST	WAIT
	LD	A,(ZZ+2)
	LD	B,A
	LD	A,(OPNWRK+40H*5+1BH)
	AND	38H
	OR	B
	OUT	(FM1DAT),A
	RST	WAIT
	LD	A,0A2H
	OUT	(FM1REG),A
	RST	WAIT
	LD	A,(ZZ+1)
	OUT	(FM1DAT),A
	RET

;----------------------------------------------------------------------
;	SOUND CHANGE TABL 1
;----------------------------------------------------------------------

CHGTL1:
	DEFB	030H,038H,034H,03CH,040H,048H
	DEFB	044H,04CH,050H,058H,054H,05CH
	DEFB	060H,068H,064H,06CH,070H,078H
	DEFB	074H,07CH,080H,088H,084H,08CH

;----------------------------------------------------------------------
;	SOUND CHANGE TABL 2
;----------------------------------------------------------------------

CHGTL2:
	DEFB	031H,039H,035H,03DH,041H,049H
	DEFB	045H,04DH,051H,059H,055H

	LD	(IX+7),L
	LD	(IX+8),H
	LD	(IX+5),0
	CALL	PSGSET		;PSG TONE SET
	JP	PSGADR

;--------------------------------------------

		 NCRET

;----------------------------------------------------------------------
;	LOOP START POINT		(F7)
;----------------------------------------------------------------------

PSGF7:
	POP	HL
	LD	A,(HL)
	LD	(IX+0DH),A
	INC	HL
	LD	(IX+0BH),L
	LD	(IX+0CH),H
	JP	FNCRET

;----------------------------------------------------------------------
;	LOOP END OPINT		(F8)
;----------------------------------------------------------------------

PSGF8:
	POP	HL
	DEC	(IX+0DH)
	LD	A,(IX+0DH)
	OR	A
	JP	Z,FNCRET
	LD	L,(IX+0BH)
	LD	H,(IX+0CH)
	JP	FNCRET

;----------------------------------------------------------------------
;	SUBROUTIN CALL		(F9)
;----------------------------------------------------------------------

PSGF9:
	POP	HL
	LD	E,(HL)
	INC	HL
	LD	D,(HL)
	INC	HL
	LD	(IX+9),L
	LD	(IX+0AH),H
	EX	DE,HL
	JP	FNCRET

;----------------------------------------------------------------------
;	RETURN			(FA)
;----------------------------------------------------------------------

PSGFA:
	POP	HL
	LD	L,(IX+9)
	LD	H,(IX+0AH)
	JP	FNCRET

;----------------------------------------------------------------------
;	OCTAVE TRNCE POSE		(FB)
;----------------------------------------------------------------------

PSGFB:
	POP	HL
	LD	A,(HL)
	INC	HL
	LD	(IX+10H),A
	JP	FNCRET

;----------------------------------------------------------------------
;	PSG FUNCTION SET	(FC)
;----------------------------------------------------------------------

PSGFC:
	POP	HL
	JP	FNCRET

;----------------------------------------------------------------------
;	PSG FUNCTION SET	(FD)
;----------------------------------------------------------------------

PSGFD:
	POP	HL
	JP	FNCRET

;----------------------------------------------------------------------
;	PSG FUNCTION SET	(FE)
;----------------------------------------------------------------------

PSGFE:
	POP	HL
	JP	FNCRET

;----------------------------------------------------------------------
;	PSG FUNCTION SET	(FF)
;----------------------------------------------------------------------

PSGFF:
	POP	HL
	LD	(IX+0),0
	LD	(IX+0EH),0
	LD	A,(CHANNO)
	SUB	9
	CP	3
	JR	NC,??10		;CH12~CH14
	ADD	A,8
	OUT	(FM1REG),A
	NOP
	NOP
	XOR	A
	OUT	(FM1DAT),A
	RET

??10:	SUB	3		;CH12~CH14
	ADD	A,8
	OUT	(FM2REG),A
	NOP
	NOP
	XOR	A
	OUT	(FM2DAT),A
	RET

;**********************************************************************
;*	PSG SOUND OUT					*
;*	   IN  -
;*	   OUT -
;*		AF BC DE HL IX IY				*
;**********************************************************************

PSGOUT:
	BIT	0,(IX+12H)
	JP	Z,??30
	BIT	1,(IX+12H)
	JP	Z,??20
	RES	1,(IX+12H)
	LD	L,(IX+13H)
	LD	H,(IX+14H)
	LD	E,(IX+19H)
	LD	D,(IX+1AH)
	OR	A
	SBC	HL,DE
	JP	P,??10
	LD	DE,0
	EX	DE,HL
	OR	A
	SBC	HL,DE
	EX	DE,HL
	LD	C,(IX+1BH)
	LD	B,(IX+1CH)
	LD	(IX+1DH),C
	LD	(IX+1EH),B
	CALL	PLTSUB
	LD	HL,0
	LD	DE,(ZZ)
	LD	A,(ZZ+2)
	LD	B,A
	XOR	A
	SBC	HL,DE

(Source: Original TCRF research)