Is 4200h-42FFh still unused???

80sFREAK · Post by **80sFREAK** » Thu Apr 12, 2012 2:30 am

Googled this question for a while, but found nothing. Is anyone can confirm, that 4200-42FFh still not used in any mapper or other projects.
Thanks in advance for any helpful info

Post by **lidnariq** » Thu Apr 12, 2012 8:55 am

The only addresses I would assume don't collide with any mapper hardware ever are the mirrors of PPU used on the opposite direction. (e.g. reading from $3ff8, writing to $3ffa, &c)

Searching through the Nestopia source found one board ("Fukutake") that has something mapped into $4200-$43FF.

80sFREAK · Post by **80sFREAK** » Fri Apr 13, 2012 8:41 pm

This? http://svn.opennestopia.staulkor.com/Ne ... kutake.cpp

B00daW · Post by **B00daW** » Fri Apr 13, 2012 9:36 pm

This tape device?

http://www.nesworld.com/studybox.php

80sFREAK · Post by **80sFREAK** » Sat Apr 14, 2012 12:07 am

Thanks for the link. Will keep this device in my mind, but this just will not fit my project

Post by **lidnariq** » Sat Apr 14, 2012 12:14 pm

Looking through the wiki, it looks like many other mappers overlap with $42XX also.

80sFREAK · Post by **80sFREAK** » Sat Apr 14, 2012 5:40 pm

lidnariq wrote:Looking through the wiki, it looks like many other mappers overlap with $42XX also.

Official ones? Could you please give me link

Post by **lidnariq** » Sat Apr 14, 2012 6:33 pm

If you're going to restrict it to NES official ones, why bother caring with anything more than MMC1-6 and the discrete mappers? But if you're aiming for Famicom or Famiclone compatibility, I don't think that's reasonable — who knows what unlicensed stuff people will try to run?

80sFREAK · Post by **80sFREAK** » Sat Apr 14, 2012 9:49 pm

NES+Famicom, don't really care about clones and pirate carts, but just in case

80sFREAK · Post by **80sFREAK** » Sun Apr 22, 2012 3:48 am

lidnariq wrote:Looking through the wiki, it looks like many other mappers overlap with $42XX also.

http://wiki.nesdev.com/w/index.php/INES_Mapper_113 This? How about

$4200 does not map to the register, but $4300 does.

http://wiki.nesdev.com/w/index.php/INES_Mapper_079 This? Same.

What else?

Post by **lidnariq** » Mon Apr 23, 2012 12:08 am

in nestopia's source, I found the following:
NstBoardTxc.cpp (0x4120-0x7fff)
NstBoardCneShlz.cpp (0x4020-0x5fff)
NstBoardBtl6035052.cpp (0x4020-0x7fff)
NstBoardBmc150in1.cpp (0x4020-0xffff)
NstBoardBtlSmb2b.cpp (0x4020-0x4040, 0x40a0-0x40c0, 0x4120-0x4140, 0x41a0-0x41c0 ... 0x5fc0)
I already mentioned NstBoardFukutake.cpp

80sFREAK · Post by **80sFREAK** » Mon Apr 23, 2012 8:10 am

lidnariq wrote:in nestopia's source, I found the following:
NstBoardTxc.cpp (0x4120-0x7fff)
NstBoardCneShlz.cpp (0x4020-0x5fff)
NstBoardBtl6035052.cpp (0x4020-0x7fff)
NstBoardBmc150in1.cpp (0x4020-0xffff)

no bother

NstBoardBtlSmb2b.cpp (0x4020-0x4040, 0x40a0-0x40c0, 0x4120-0x4140, 0x41a0-0x41c0 ... 0x5fc0)

this might overlap. Is it official release or hack?

I already mentioned NstBoardFukutake.cpp

out of question - unit will not fit.

3gengames · Post by **3gengames** » Mon Apr 23, 2012 12:15 pm

Does it really matter? C'mon...either accept that basically all parts of memory are used sometime, or don't make a mapper.

chykn · Post by **chykn** » Mon Apr 23, 2012 12:39 pm

Just out of curiosity, what are you looking to do with this address range? Use it to reference an external device?

80sFREAK · Post by **80sFREAK** » Mon Apr 23, 2012 10:22 pm

3gengames wrote:Does it really matter? C'mon...either accept that basically all parts of memory are used sometime, or don't make a mapper.

No, it's not for mapper.

chykn wrote:Use it to reference an external device?

Yes. Well, not exactly external, but device(devices)