Prepare NES machine type

include/crt.c

@@ -131,6 +131,9 @@ lx1:	lda (addr), y
 
 #elif defined(OSCAR_TARGET_BIN)
 
+#elif defined(OSCAR_TARGET_NES)
+		sei
+		cld
 #else		
 		byt	0x0b
 		byt 0x08
@@ -153,6 +156,7 @@ lx1:	lda (addr), y
 		stx spentry
 
 #endif
+
 // Clear BSS Segment
 
 		lda #<BSSStart
@@ -239,6 +243,7 @@ l2:		dey
 #endif
 
 spexit:
+#if !defined(OSCAR_TARGET_NES)
 		lda	#$4c
 		sta	$54
 		lda #0
@@ -248,6 +253,7 @@ l2:		dey
 #if defined(__C128__)
 		lda #0
 		sta 0xff00
+#endif
 #endif
 		rts
 }

include/nes/nes.c

@@ -0,0 +1,2 @@
+#include "nes.h"
+

include/nes/nes.h

@@ -0,0 +1,76 @@
+#ifndef NES_NES_H
+#define NES_NES_H
+
+#include <c64/types.h>
+
+#define PPU_CTRL_NT_2000	0b00000000
+#define PPU_CTRL_NT_2400	0b00000001
+#define PPU_CTRL_NT_2800	0b00000010
+#define PPU_CTRL_NT_2C00	0b00000011
+#define PPU_CTRL_INC_1		0b00000000
+#define PPU_CTRL_INC_32		0b00000100
+#define PPU_CTRL_SPR_0000	0b00000000
+#define PPU_CTRL_SPR_1000	0b00001000
+#define PPU_CTRL_BG_0000	0b00000000
+#define PPU_CTRL_BG_1000	0b00010000
+#define PPU_CTRL_SPR_8X8	0b00000000
+#define PPU_CTRL_SPR_8X16	0b00100000
+#define PPU_CTRL_NMI		0b10000000
+
+#define PPU_MASK_GREYSCALE	0b00000001
+#define PPU_MASK_BG8		0b00000010
+#define PPU_MASK_SPR8		0b00000100
+#define PPU_MASK_BG_ON		0b00001000
+#define PPU_MASK_SPR_ON		0b00010000
+#define PPU_MASK_EM_RED		0b00100000
+#define PPU_MASK_EM_GREEN	0b01000000
+#define PPU_MASK_EM_BLUE	0b10000000
+
+struct PPU
+{
+	volatile byte	control;
+	volatile byte	mask;
+	volatile byte	status;
+	volatile byte	oamaddr;
+	volatile byte	oamdata;
+	volatile byte	scroll;
+	volatile byte	addr;
+	volatile byte	data;	
+};
+
+#define ppu	(*((struct PPU *)0x2000))
+
+struct NESIO
+{
+	volatile byte	sq1_volume;
+	volatile byte	sq1_sweep;
+	volatile word	sq1_freq;
+
+	volatile byte	sq2_volume;
+	volatile byte	sq2_sweep;
+	volatile word	sq2_freq;
+
+	volatile byte	tri_volume;
+	volatile byte	tri_pad;
+	volatile word	tri_freq;
+
+	volatile byte	noise_volume;
+	volatile byte	noise_pad;
+	volatile word	noise_freq;
+
+	volatile byte	dmc_freq;
+	volatile byte	dmc_raw;
+	volatile byte	dmc_start;
+	volatile byte	dmc_length;
+
+	volatile byte	oamdma;
+	volatile byte	channels;
+	volatile byte	input[2];
+};
+
+#define nesio	(*((struct NESIO *)0x4000))
+
+#pragma compile("nes.c")
+
+#endif
+