added code to handle multiple platform rom builds with rom size override

Source/HBIOS/Makefile

@@ -1,4 +1,4 @@
-OBJECTS = ZETA2_std.rom
+OBJECTS = ZETA2_std.rom N8_std.rom
 MOREDIFF = camel80.bin game.bin hbios_rom.bin nascom.bin prefix.bin usrrom.bin \
 	dbgmon.bin hbios_app.bin imgpad0.bin osimg1.bin romldr.bin \
 	eastaegg.bin hbios_img.bin imgpad.bin osimg.bin tastybasic.bin \
@@ -11,8 +11,16 @@ OTHERS =  *.bin *.z80 cpm.sys zsys.sys Build.inc
 include $(TOOLS)/Makefile.inc
 DIFFPATH = $(DIFFTO)/Binary
 
-ZETA2_std.rom:
-	bash Build.sh ZETA2 std 512
+
+ROMSIZE=512
+
+N8_std.rom: ROMSIZE=1024
+
+%.rom:
+	bash Build.sh $(shell echo $* | tr '_' ' ') $(ROMSIZE)
+
+#ZETA2_std.rom:
+#	bash Build.sh ZETA2 std 512
 
 hbios_rom.bin:	hbios.asm
 	$(TASM) -dROMBOOT hbios.asm hbios_rom.bin