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 Post subject: First reproduction help
PostPosted: Fri Oct 14, 2016 6:45 pm 
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Joined: Thu Jun 19, 2014 6:21 pm
Posts: 6
Hello everyone. I have a question. I am looking into doing a tetrastar reproduction.

Will a fighting golf PCB board work as a donor board?

here is some info, but I am still confused.

http://bootgod.dyndns.org:7777/profile.php?id=470

Fighting Golf 128k PRG / 128k CHR H MMC1 (1)
Tetrastar 256k PRG / 256k CHR V MMC3 (4)


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PostPosted: Fri Oct 14, 2016 7:10 pm 
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Joined: Sun Apr 13, 2008 11:12 am
Posts: 6297
Location: Seattle
At the very least, you need to match mapper IC.

Tetrastar is mapper 4, which means it's (very likely) MMC3. You either need a donor with an MMC3 on it, or a board with an MMC3 clone on it.

Additionally, the game might want PRG RAM. Since Tetrastar isn't in NesCartDB, and the game is not battery backed, the only way to determine this is to play for a while in a debugging emulator and see if it reads or writes addresses $6000-$7FFF.


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PostPosted: Sun Oct 16, 2016 6:40 pm 
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Joined: Thu Jun 19, 2014 6:21 pm
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lidnariq wrote:
At the very least, you need to match mapper IC.

Tetrastar is mapper 4, which means it's (very likely) MMC3. You either need a donor with an MMC3 on it, or a board with an MMC3 clone on it.

Additionally, the game might want PRG RAM. Since Tetrastar isn't in NesCartDB, and the game is not battery backed, the only way to determine this is to play for a while in a debugging emulator and see if it reads or writes addresses $6000-$7FFF.



That makes sense. As for EPROMs. since it is listed that the game is 256k for both CHR and PRG shouldn't I go with this?:

http://www.datasheetcatalog.com/datashe ... C020.shtml


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PostPosted: Sun Oct 16, 2016 7:27 pm 
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Location: Seattle
A 27'020 can hold 256 KiB, yes.

There are no new UVEPROMs anymore; only used ones (and rarely new-old-stock). The only still-manufactured DIP 5V memory of this capacity is the SST39SF020A.


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PostPosted: Sun Oct 16, 2016 8:10 pm 
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Joined: Mon Sep 05, 2016 3:33 pm
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I use the 27C2001 EPROMs. Takes a month from China but cheap.


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PostPosted: Wed Nov 09, 2016 5:23 pm 
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Joined: Thu Jun 19, 2014 6:21 pm
Posts: 6
Alright,

So I split the ROM image into a CHR and PRG BIN.
The EPROMs I ended up going with are AM27C040. Since both the CHR and PRG are both 256K and the EPROMS are 512k, I doubled up the CHR and PRG until they were both 512k respectively.

I ended up using BILL ELLIOTT'S NASCAR CHALLENGE as a donor PCB.

Also, I ran tetrastar with a debug emulator and saw that it might be using PRG RAM. It showed values past $6000.

I followed this diagram:

256KB PRG ROM:
Bend up pins 1, 2, 24, 30, and 31.
Connect pin 1 to hole 30
Connect pin 2 to hole 24
Connect pin 24 to pin 16
Connect pin 30 to hole 1
Leave pin 31 disconnected

256KB CHR ROM:
Bend up pins 1, 2, 22, 24, 30, and 31.
Connect pin 1 to hole 30
Connect pin 2 to hole 24
Connect pin 22 to hole 31
Connect pin 24 to hole 2
Connect pin 30 to hole 1
Leave pin 31 disconnected

Image

Image

First time in my life I have soldered.

Does anyone have any suggestions? It still is not working. All I get is a gray screen when I power on the nes.


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PostPosted: Thu Nov 10, 2016 10:39 am 
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Joined: Tue Dec 04, 2012 3:28 pm
Posts: 337
Location: Canada
Judging from the look of the holes on the underside of the board I'd say that you need to solder all of those again. Some of them don't even look like they've been soldered?

One piece of advice, buy solder flux. It will help you a ton, especially if you're inexperienced in this.


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PostPosted: Thu Nov 10, 2016 4:57 pm 
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Joined: Thu Jun 19, 2014 6:21 pm
Posts: 6
Thanks for the reply. I thought the ICs do not need to be completely soldered to be able to read? For example for soldering the corner pins in.


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PostPosted: Thu Nov 10, 2016 5:20 pm 
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Joined: Sun Sep 19, 2004 11:12 pm
Posts: 19116
Location: NE Indiana, USA (NTSC)
Two of the corner pins provide power to the memory. Of course the power pins need to be soldered properly.


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