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PostPosted: Mon May 22, 2017 5:27 pm 
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Hi, I just got a Dynavision 5 and Dynavision 6 consoles, both are NOAC based.
I've done the Castlevania 3 fix on the last and all seems fine on both.

Unfortunatelly none of them seem able to play my 2 in 1 made with a SD74LS74AE, a W49F002U, a 29EE020 and a pirate not marked MMC1 clone.
Sometimes it starts one of the games, but pressing reset to change the game makes it crash.
The flip-flop seems fine, changing its output from 0 to 1 on each reset.
The game plays fine on other discrete IC clone I have.
Can this somehow be fixed??
I just can't understand why the problem... I even added some missing decopling caps (104) but no deal.

Thans in advance.


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PostPosted: Mon May 22, 2017 6:04 pm 
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Fisher wrote:
Sometimes it starts one of the games, but pressing reset to change the game makes it crash.
The flip-flop seems fine, changing its output from 0 to 1 on each reset.
Implies that the flip-flop isn't changing value during reset (while M2 is HiZ), but instead at the end of reset, causing it to fetch a few bytes from one bank before switching to the other.

What're the passives you have hooked up to the 74LS74's input?


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PostPosted: Mon May 22, 2017 6:49 pm 
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A dione (1N4148) and a ceramic capacitor (103).
Code:
M2---|<---+---Flip-flop
   1N4148 |
          = 103
          |
         GND

Would the flip-flop have some problem? I think it was made in 73!! (datecode is: 725F).

I'm using this board:
Soldering side and Component side.


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PostPosted: Mon May 22, 2017 7:04 pm 
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Fisher wrote:
A diode (1N4148) and a ceramic capacitor (103).
Code:
M2---|<---+---Flip-flop
   1N4148 |
          = 103
          |
         GND
A 74LS (also letterless, L, H, F, S) effectively has a pull-up resistor on all input pins because it signals a logic 1 as "current is not flowing" and a logic 0 as "current is flowing".

Quote:
Would the flip-flop have some problem?
I don't see how. When M2 stops oscillating, if M2 is the same as in the 2A03, it'll go high-Z, and the pin will float high. At that point, because the 74'74 latches the D pin on a rising edge, that's when it should change.
Quote:
I think it was made in 73!! (datecode is: 725F).
With an F there it's unlikely it's a 4-digit date code.

I didn't think we had LS series parts as early as 1972? Wikipedia claims 1976.


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PostPosted: Mon May 22, 2017 7:16 pm 
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I found very weird that it just works as-is in a no NOAC clone.
I wish I could mod the NOACs to accept this cartridge as-is, but I don't know if it's even possible.


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PostPosted: Mon May 22, 2017 7:19 pm 
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If it were me, I'd put an oscilloscope on M2, the 74'74's ↑CLK, and the 74'74's D pins and see what happened.
But I don't really have any ideas for diagnosing what's going wrong or how to fix it without that.


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PostPosted: Mon May 22, 2017 7:30 pm 
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I guess that's it...
Until I can get some nice tools to troubleshoot it I'll just accept that this game just don't works.
Maybe I do some videos with the weird bugs I'm finding...
On the stage 2 of Ninja Gaiden 3, Ryu just runs behind the sand... that's odd and hilarious at the same time!!
Seems that the lack of /PA13 is not the only flaw of this chip!!
Thanks!


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PostPosted: Mon May 22, 2017 7:36 pm 
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I mean, if you're in "just fling things at the wall and see what sticks" range, try moving the diode from M2 to instead CPU A0, and replace the 103=10nF capacitor with a 100nF one.


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PostPosted: Tue May 23, 2017 5:05 pm 
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Thanks for the tip, I'll try it as soon as I can.

Just out of curiosity I opened both consoles.
Although their boards are the same size, they're pretty different.

In fact, the Dynavision 5 gave me no problem to run Castlevania 3.
I tested it now with the decoupling capacitors added and it ran the multicart just fine!
The NOAC it uses is an epoxy blob on a small board (I didn't take it of the board, just saw some pics in the web) and is labeled UM6561-A-4.
Externally the console dark gray with yellow power and reset buttons. The cartridge lid is yellow too.

The Dynavision 6 has many bugs, needed a fix to run CV3, don't runs the multicart and has many bugs in Ninja Gaiden 3.
His NOAC is similar to the other, but obviously has a different pinout and is labeled IC6655-2001-11-16.
Externally the console is light gray and blue. The buttons and the lid are gray too.
It has a label with an big X and the word "Dynacom" on the place where the buttons are located.
It has the words Dynavision Xtrene written on the right.

I know some pictures would be nicer but I just don't know why I can't attach them from my phone... maybe it's browser update broke something.

Does anyone know something else about these NOACs?
Maybe I should do some videos with them, I could call it "crappy game play with finicky Famiclones'.:-)

Edit: Looks like FARID has done a nice job building his own UM6561 NOAC Famiclone. That's really cool!!
The UM6561 seems to be a very nice NOAC, while the other one isn't.


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