MHROM ?

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MHROM ?
by nintendo2600 on 2009-05-21 (#47095)
Hey,

What can the MHROM smb\DH boards be used for? As in is it compatible with say CNROM or NROM by any chance? I got my hands on a couple
prom chiped smb\dh boards and I would like to put them to use. It was kinda neat coming across them as sooooo many are epoxy drops.

Cheers,

Shawn

by Bregalad on 2009-05-21 (#47098)
MHROM and GNROM is an extension of CNROM which allow for PRG bankswitching. It is fully compatible with CNROM. In addition to that it's fully compatible with regular 27Cxxx EPROMs pinout.

by tokumaru on 2009-05-21 (#47101)
I thought all SMB+DH carts used glop-tops... This is not the case then?

by BootGod on 2009-05-21 (#47116)
Yeah actually they even managed to go thru 5 revisions of the normal MHROM PCB! [url=http://bootgod.dyndns.org:7777/search.php?keywords=&group=cartid&unif=mhrom&unif_op=LIKE%20%60%@%%60&field=9&order=asc]A listing[/url]

by Memblers on 2009-05-21 (#47130)
Most of them are glop-tops, but you can tell which ones have chips because they have all 72 pins on the bottom.

The labels look different on the older ones, easiest to notice there isn't a "Seal of Approval" (oh noes! :)). But those can have any kind of board inside.

I actually used MHROM for Garage Cart #1, however I used RAM for the CHR (needed a wire from the cart edge).

I may be remembering wrong, but the banking seemed able to use 128kB PRG (Nintendo's 28-pin one).

by nintendo2600 on 2009-05-21 (#47136)
Bregalad wrote:
MHROM and GNROM is an extension of CNROM which allow for PRG bankswitching. It is fully compatible with CNROM. In addition to that it's fully compatible with regular 27Cxxx EPROMs pinout.


Thanks for your response! :)

by Bregalad on 2009-05-22 (#47139)
Also it seems European versions are never epoxy blob revision (the more common SMB/Tetris/Nintendo World Cup has epoxy blobs tough).

by mark_k on 2009-05-22 (#47174)
Bregalad wrote:
Also it seems European versions are never epoxy blob revision (the more common SMB/Tetris/Nintendo World Cup has epoxy blobs tough).
I'm not sure how common the blob version is compared to the DIP IC version, but at least some PAL SMB/DH carts have the epoxy blob board. One of the entries in BootGod's database shows it, and I have a UK version cart (label NES-MH-UKV) which uses that type of board too.

-- M

by Bregalad on 2009-05-23 (#47191)
Oh forget what I said then.