nesdev.parodius.com

kyuusaku · Joined: 27 Sep 2004 Posts: 1354 Location: .ma.us

The ROM is 16-bit wide but file data is addressed sequentially in 8-bit bytes, so the "endianness" determines which byte is placed in the upper and lower 8-bits of the 16-bit word. The circuit is configured for big-endian data (even bytes are D15-8), but there's a good chance the Willem software chose little-endian. But if this is the case, you don't need to reburn the ROM (normally you would), you just need to exchange 139 pins 4 and 5 which in effect swaps bytes.

lunaris · Joined: 03 Jun 2009 Posts: 28

lunaris · Joined: 03 Jun 2009 Posts: 28

What my test cart looks like:

Using SN74LS139AN + (2x)SN74LS245AN + a Zif Socket for 27c322 and a HiRom cart with SRAM and MAD-1.

Extra WIIIIIDE picture

Also, if I want to make a 48mbit game like Tales of Phantasia English Patched... I would need 2 16-bit eproms for the task.. Is it even possible to link up 2 27c322 to 1 snes bus?

X-death · Joined: 03 Jul 2010 Posts: 1

hi,
i would like ton make my personel home made cart for SNES with a 27c322.

can you tell me if my schéma is ok ?

http://sega4ever.power-heberg.com/tutodedev/27c322%20in%20Snes/sh%e9ma%2027c322%20%20in%20Snes%20cart.png

thanks Wink

lunaris · Joined: 03 Jun 2009 Posts: 28

lunaris · Joined: 03 Jun 2009 Posts: 28

Also, and I should probably just PM Kyuusaku for help on this one, but.. I'll try my luck on this thread first.

Would piggybacking another 27c322 onto the first one and connecting the lifted pin 13 (EPROM /OE a.k.a. GVpp) legs to the mad-1 as follows work out fine? I tried it and I didn't get it working.

http://nintendoallstars.w.interia.pl/romlab/mads.htm

So I used that link, connected the /OE's of the eproms to the mad-1 as followed. I also have a 48mbit cart of Tales of Phantasia and that is how they seem to connect it. Would the data lines still function correctly with the 245 setup?

Someone said maybe I should be tying the eprom legs of pin 11 of the 27c322 (/CE a.k.a. E) to the mad-1 instead.

Thanks in advance!

Cheers

kyuusaku · Joined: 27 Sep 2004 Posts: 1354 Location: .ma.us

Yeah you can piggyback, but you must separate the /CEs (everything else should be connected). Don't use ROMLab as a reference, it's all messed up.

Each ROMs is selected by its /CE using a decoder. MAD-1 has a decoder built into it, but it's a little more involved than the 139.

So right now you have one of the two decoders in the 139 selecting a 245 right? Use the other decoder to select which ROM's /CE is active.

You can do this by taking the /CE going to the current ROM, and hooking it to the 2nd decoder's /E input. From there connect the B input to GND and the A input to A22. The Y0 output should connect to the ROM containing the first 32M's /CE, the Y1 output should connect to the last 16M ROM's /CE.

lunaris · Joined: 03 Jun 2009 Posts: 28

^ Just for reference.

Right, my test cart is wired like that now, when i drop a 27c322 into the zif (just 1) it works fine! but when i stick the piggybacked 2 27c322 package with the 11th legs lifted and individually wired to the 74ls139, i dont get anything but a black screen.

EDIT: Got it working, but I grounded the E of the 139 (lol, screw saving energy? at this point)... Yea, only works when Y0 is connected to the ROM /CE of the eprom with 16mbits of data, and Y1 is connected to the ROM /CE of the eprom with 32mbits of data.. lol.

EDIT 2: Tied SNES /OE to E of 139, works!

EDIT 3:
Tested Working.

Leg 11 of 27c322 = EPROM /CE
Leg 13 of 27c322 = EPROM /OE

Pin 24 of Maskrom = SNES /CE
Pin 33 of Maskrom = SNES /OE
Pin 35 of Maskrom = A22

NC = Not Connected

Question for Kyuusaku
Is a 30awg tap for vcc and ground enough for 2 27c322's?

kyuusaku · Joined: 27 Sep 2004 Posts: 1354 Location: .ma.us

Pin 15 is tied to what? Hopefully the MAD-1's /CE output and not the console's /ROMSEL.

The way I told you to wire the 139 you cannot ground E, it's not about energy, it's about only enabling the ROM at the right time. Grounding it would cause one ROM to always be enabled and they will conflict with the console's work RAM (very bad).

The reason why "/OE" works is because it's not /OE! Again, don't use ROMLab as a reference, they have /OE and /CE reversed.

I'm not sure if 30awg is good enough. You can always put multiple wires in parallel if you don't have a better wire. Don't forget to wire in bypass capacitors too..

lunaris · Joined: 03 Jun 2009 Posts: 28

Every game works flawlessly.. (beat Terranigma and I am half way through Tales of Phantasia, Secret of Mana 2, and the ReTranslation of Final Fantasy 6). I have made and tested the saves for Bahamut Lagoon, Final Fantasy 5, Dragon Quest 1/2, 5, 6, Treasure of the Rudras, and a few more..

But Kyuusaku, I am on a venture to build a game that people have problems with - so I may be back lol Smile

. (Did I tell you I love ya?)
Dragon Quest 3 is a 32mbit game, becomes 48mbit with its translation IPS applied. If you look http://www.racketboy.com/forum/viewtopic.php?f=25&t=13416&st=0&sk=t&sd=a&start=400 you can see that these guys have problems saving. I will try it using the same method as Tales of Phantasia (piggybacking 27c322s). I hope it will work for me as that sram issue smells like incompatibility in the mad-1 pinout while using a 74ls138 + 6x8mbit eproms works fine.

Update: works fine for DQ3 according to the replies I got after i posted your 139 pinout lol (http://www.racketboy.com/forum/viewtopic.php?f=25&t=13416&st=0&sk=t&sd=a&start=410)

Random Blabbering:
"Right, MAD pin 13 going to cart pin 48 on the ToP cart, that's A22 on normal Hirom 36 pin carts. You can see the pinout here. It won't work without MAD pin 13 going cart pin 48/A22"
-electrochip (from http://www.racketboy.com/forum/viewtopic.php?f=25&t=13416&st=0&sk=t&sd=a&start=380)

Yeah, I don't mind wiring anything up to the 74ls139 because it has a decoder free. but that method also works where i previously said it did not. i did not notice pin 13 of the mad-1 is not connected to a22 on regular hirom 1 maskrom carts where it is on tales of phantasia.
So you can wire the rom /ce legs to pin 1 and 16 of the mad-1 if you lift leg 13 and wire that to a22 as the quote above said and as the schematics of the original pcb show.

This is definitely the cheapest method to produce any game repro. IMHO It is a very simple job to solder this up - but very time consuming due to a lot of wires being needed. the 29f032 with top40 to dip36 adapter method seems easiest of course - and not that hard to make an adapter, all you need is breadboard, a zif socket, and 3? wires lol..