Add NES building and adapt example functions

LibMultiSpacc/neslib/vram_read.s

@@ -0,0 +1,47 @@
+
+.importzp TEMP
+.import popa, popax
+.include "nes.inc"
+.include "zpvars.inc"
+.export _vram_read
+
+;void __fastcall__ vram_read(unsigned char *dst,unsigned int size);
+
+_vram_read:
+
+	sta <TEMP
+	stx <TEMP+1
+
+	jsr popax
+	sta <TEMP+2
+	stx <TEMP+3
+
+	lda PPU_DATA
+
+	ldy #0
+
+@1:
+
+	lda PPU_DATA
+	sta (TEMP+2),y
+	inc <TEMP+2
+	bne @2
+	inc <TEMP+3
+
+@2:
+
+	lda <TEMP
+	bne @3
+	dec <TEMP+1
+
+@3:
+
+	dec <TEMP
+	lda <TEMP
+	ora <TEMP+1
+	bne @1
+
+	rts
+
+
+