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PostPosted: Thu May 31, 2018 1:38 am 
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Joined: Thu May 31, 2018 1:29 am
Posts: 7
Hi to this community !
Nice to meet you guys !
First of all thanks for your Channel !

I'm a French beginner Carmtodder and I'm Trying to do a Rockman X2 in French... Many forum in France are not so cool, and i tried to have help but no...

I send you 2 pics :

- cx4.jpg : Are the number correct ?? Because they told me i have to connect two pins after that, but i want to be sure the numbers are in the good places..

Image

- SHVC-ARXJ-JPN.jpg : I want to Replace those two maskroms with 1x 27C160.

Image

I know that it would be preferable to take a Megaman X3 to do this, but i have 2 MMX 2 at home and i want to do it that way....

I would be very grateful if you can help me...

Thanks

Mickael


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PostPosted: Thu May 31, 2018 4:35 am 
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Location: NE Indiana, USA (NTSC)
Moving to Repro forum. (It might be confusing, but Super NES stuff goes there too.)


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PostPosted: Thu May 31, 2018 12:03 pm 
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Posts: 7388
Location: Seattle
Jipeg wrote:
- cx4.jpg : Are the number correct ?? Because they told me i have to connect two pins after that, but i want to be sure the numbers are in the good places..
Yes, the silkscreened numbers are correct. Nocash has a pinout here.

Quote:
- SHVC-ARXJ-JPN.jpg : I want to Replace those two maskroms with 1x 27C160.
The CX4 controls at run-time whether it addresses one 2 MiB ROM or two 1 MiB ROMs. We just had a thread about this here.


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PostPosted: Thu May 31, 2018 3:04 pm 
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lidnariq wrote:
Jipeg wrote:
- cx4.jpg : Are the number correct ?? Because they told me i have to connect two pins after that, but i want to be sure the numbers are in the good places..
Yes, the silkscreened numbers are correct. Nocash has a pinout here.


Thanks to be the first to very help me...

lidnariq wrote:
Quote:
- SHVC-ARXJ-JPN.jpg : I want to Replace those two maskroms with 1x 27C160.
The CX4 controls at run-time whether it addresses one 2 MiB ROM or two 1 MiB ROMs. We just had a thread about this here.
[/quote]

I'm looking to this topic but i don't find the answer... What to do to connect the 27C160 beside the 2 Maskrom...


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PostPosted: Thu May 31, 2018 3:30 pm 
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Joined: Sun Apr 13, 2008 11:12 am
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Location: Seattle
The actual literal contents of the ROM control whether the cart can address two 1 MiB ROMs or one 2 MiB ROM.

MMX2, 1.5MiB, always was on 2 ROMs.
MMX3, 2 MiB, was always on 1 ROM.

The program data in MMX3 configures the CX4 to address one 2 MiB ROM. The data in MMX2 configures the CX4 to address two 1 MiB ROMs.

On the 2DC0N board, the left one (labeled U1) is the "first" one. Both ROMs are connected completely in parallel, EXCEPT that they each have their own chip enable pin.


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PostPosted: Fri Jun 01, 2018 9:24 am 
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lidnariq wrote:
The actual literal contents of the ROM control whether the cart can address two 1 MiB ROMs or one 2 MiB ROM.

MMX2, 1.5MiB, always was on 2 ROMs.
MMX3, 2 MiB, was always on 1 ROM.


I really understand that. But do you agree when i say its possible to use 1 x 27C160 on the PCB of MMX 2 ?

lidnariq wrote:
On the 2DC0N board, the left one (labeled U1) is the "first" one. Both ROMs are connected completely in parallel, EXCEPT that they each have their own chip enable pin.

[/quote]

Sounds interesting ! So i can put my 27C160 in parallele to the 2 maskrom on MMX2 and it will works ?
What Schem do i have to follow ?

Thanks


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PostPosted: Fri Jun 01, 2018 9:48 am 
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Location: Seattle
Jipeg wrote:
I really understand that. But do you agree when i say its possible to use 1 x 27C160 on the PCB of MMX 2 ?
A ROM is just a ROM. However, the specific connections matter.

The CX4 can only address a byte-wide ROM. The 27C160 has to be configured accordingly.

The pin order between the that UVEPROM and the original mask ROM differs dramatically.

Quote:
Sounds interesting ! So i can put my 27C160 in parallel to the 2 maskrom on MMX2 and it will works ?
Yes, but you have to disable the existing ROMs in order to prevent a bus conflict.

Quote:
What Schem do i have to follow ?
Use the pinout of the CX4, the existing ROMs, and that of the M27C160.

Because the 27C160 uses word addresses, you need to connect its A-1 to CX4 A0, 27C160 A0 to CX4 A1, and so on up.

UV EPROM "E" is "CE" or "CS" in other IC naming, and "G" is "OE" or "RD"


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PostPosted: Fri Jun 01, 2018 4:18 pm 
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Thanks again for helping.
Since i'm a beginner i will try to go step by step :

1) I withdraw the 2 maskroms (in red)

Image
delete change account

2) I take my 27C160 :

Image

3) What is the right Pinout About the Maskrom of MMX2 ?
Since they have 32 Pins, i do not find the right one you gave me in the adresse http://problemkaputt.de/fullsnes.htm#sn ... tsromchips

Image

Is this One Correct ?

Image

Thanks..


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PostPosted: Fri Jun 01, 2018 4:36 pm 
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Joined: Sun Apr 13, 2008 11:12 am
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Location: Seattle
I think that copy of Nocash's pinout is correct, but you can cross-check against his pinout of the CX4.

But yes, that's basically the correct instructions.


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PostPosted: Sun Jun 03, 2018 4:08 pm 
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Ok thanks, since i know the pinout is correct, please can you tell me how i connect the 27C160 to the 2 MaskRom (i will withdraw them).
But can you tell me how to connect each other ?
A17 to A17 ? ....


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PostPosted: Sun Jun 03, 2018 4:26 pm 
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Location: Seattle
The 27C160 is a 16-bit ROM; its address lines specify an address in 16-bit words.
The CX4 wants to talk to an 8-bit ROM.

Therefore, tie /BYTE low, and connect
ROM A-1 to CX4 A0
ROM A0 to CX4 A1
ROM A1 to CX4 A2
and so on up.


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PostPosted: Mon Jun 04, 2018 5:50 am 
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thanks, here is my scheme, do you think its a good one ?

A friend of mine told me to just put together the #26 and #27 of the CX4.
Do you think its better if i use 2 x 27C801 ?


Image


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PostPosted: Mon Jun 04, 2018 10:45 am 
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Posts: 7388
Location: Seattle
Jipeg wrote:
thanks, here is my scheme, do you think its a good one ?
No. I said that you had to connect CX4 A12 to 27C160 A11, and so on.

Quote:
A friend of mine told me to just put together the #26 and #27 of the CX4.
Do not short them together. If that even works, it could damage the CX4 and eventually stop working.
Quote:
Do you think its better if i use 2 x 27C801
Well, it makes the rewiring instructions simpler, but I think I've heard they're much more expensive.


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PostPosted: Tue Jun 05, 2018 6:01 am 
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Thanks for the help !
Sounds difficult BUT, i need to find differents way to go !

So, what do you think about this one, if i want to make a MMX2/3 with a MMX3 PCB.

Image

I got 2 x 27C801, how can i do so to make a MM2 with a MMX2 PCB ?


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PostPosted: Tue Jun 05, 2018 9:49 am 
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Posts: 7388
Location: Seattle
Jipeg wrote:
So, what do you think about this one, if i want to make a MMX2/3 with a MMX3 PCB.
First thing first: That's fine for putting MMX3 on an MMX3 board.

However. In the data programmed to the ROM is a command that controls whether the game addresses one ROM or two ROMs. So I think you'll have difficulty if you program MMX2 in and just place that on an MMX3 board.

Quote:
I got 2 x 27C801, how can i do so to make a MM2 with a MMX2 PCB ?
Just connect them, like-named pin to like-named pin. This case should be straightforward.

MMX2 is 1.5MiB, so split it into the first 1 MiB and last 512 KiB; the first 1 MiB go onto the "U1" footprint and the last 512 KiB go onto the "U2" footprint.


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