Akira TC0190 questions

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DamienC
Posts: 13
Joined: Fri Apr 29, 2016 8:39 am

Akira TC0190 questions

Post by DamienC » Wed May 11, 2016 1:09 pm

I'd like to apply the fan translation of Akira to my Famicom cart. I already traced out all the pins so I'm not worried about wiring, although there are some things I'm concerned about before I start desoldering:

The fan translation expands the PRG from 128 kilobytes to 256 kilobytes. I'm guessing that this shouldn't be a problem, but I couldn't find a lot of information about this.

Also the game uses two 128 kilobyte CHR mask ROMs, and it looks to be controlled by a 74HC139AP decoder. I'm sort of a layman in terms of how this particular Taito chip handles this, but from what I traced out it appears that the TC0190 sends inputs to the 74HC139AP to decide which CHR ROM chip is currently needed and switches as necessary. This is all guesswork on my part.

What I'd like to know is, could I use a single 256 kilobyte EPROM like a 27C020 and bypass the 74HC139 by soldering leads directly to the TC0190? Or is the program expecting two CHR ROMs and the 74 chip to be in the circuit to function properly?

Finally, assuming I HAVE to use a pair of 128 kilobyte EPROMs for the CHR ROMs, how do I split the CHR file? Every ROM utility I can find spits out a 256 kilobyte CHR bin file, and I didn't want to assume I could just download a generic file splitter program and divide it in two and burn the EPROMs.

lidnariq
Posts: 9766
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Location: Seattle

Re: Akira TC0190 questions

Post by lidnariq » Wed May 11, 2016 1:26 pm

DamienC wrote:The fan translation expands the PRG from 128 kilobytes to 256 kilobytes. I'm guessing that this shouldn't be a problem, but I couldn't find a lot of information about this.
Per http://wiki.nesdev.com/w/index.php/Taito_TC0190_pinout
that should work fine.
DamienC wrote:What I'd like to know is, could I use a single 256 kilobyte EPROM like a 27C020 and bypass the 74HC139 by soldering leads directly to the TC0190?
Yes.

DamienC
Posts: 13
Joined: Fri Apr 29, 2016 8:39 am

Re: Akira TC0190 questions

Post by DamienC » Wed May 11, 2016 1:41 pm

Awesome, I'll try this out tonight with a 27C020 or 27C040 (depending what I have lying around).

Thanks.

DamienC
Posts: 13
Joined: Fri Apr 29, 2016 8:39 am

Re: Akira TC0190 questions

Post by DamienC » Fri May 13, 2016 4:54 am

OK I thought I had it working but apparently it's being flaky. PRG is fine, the game starts and I can hear music perfectly.

CHR is apparently not right. I swear it worked the way I had this wired because I played the game for a good 20 minutes yesterday, but when I got home and tried again the graphics were corrupted.

The 74HC139AP is removed but I'm using some of the holes as solder points for some pins on the CHR.

Currently my EPROM is wired like this:

Pins 1, 2, 30, 31, 32 lifted
Pin 1 float
Pin 2 to hole 24 (A16)
Pin 22 (CHR /CE?) to 74HC139 hole 3 (PPU A13)
Pin 23 (CHR A10) to 74HC139 hole 1 (PPU /RD)
Pin 30 to 74HC139 hole 2 (CHR A17)
Pin 31 float
Pin 32 to +5V (I tied this to CHR1 pin 28 out of convenience)

I'm almost positive that the issue is PPU A13 and PPU /RD as I'm not entirely positive where to wire them, or if I should be wiring them at all. The wiki (http://wiki.nesdev.com/w/index.php/Cartridge_connector) states that CHR /CE is usually tied to A13 so that's why I had it where it is.

Can anyone point me in the right direction?

lidnariq
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Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Akira TC0190 questions

Post by lidnariq » Fri May 13, 2016 10:28 am

PPU /RD and A13 should be connected to ROM /OE and /CE respectively.

CHR A0..A9 should come from the card edge. CHR A10..A18 should come from the TC0190 ... at least, up to the size of the image you're trying to burn/flash.

DamienC
Posts: 13
Joined: Fri Apr 29, 2016 8:39 am

Re: Akira TC0190 questions

Post by DamienC » Sat May 14, 2016 6:13 am

lidnariq wrote:PPU /RD and A13 should be connected to ROM /OE and /CE respectively.
That's it. I had pin 24 (CHR /OE) tied to GND. I moved it to PPU /RD and now it works perfectly.

Thanks.

Ice Man
Posts: 546
Joined: Fri Jul 04, 2014 2:34 pm

Re: Akira TC0190 questions

Post by Ice Man » Wed Feb 12, 2020 7:40 am

Digging up this topic again because I'm having issues myself.
I have done Akira carts using Akira as a donor just fine but I have a Takeshi no Sengoku Fuuunji now and no matter what I do, the PRG ROM is never dumps correct. CHR does though (I removed the 74'245 and reconneced PPU D0-D7 to CHR D0-D7).

Connected PRG A17 to TC0190 pin 13
Connected PRG A18 to TC0190 pin 14

What I noticed though, pin 31 and pin 35 of TC0190 are tied on Akira. I did that too but it didn't change anything.

Sadly I didn't test the game before so I cannot exclude the defect of a TC0190 either.

I did test the EPROM in 3 different programmers though. Even used a 2nd one. They're clearly not at fault.

Even tested all pins for their connections and all of them are connect. No broken traces either.
Funnily enough the CRC is different sometimes, so I don't know what's going on...


EDIT: I got it working. I had PPU /OE tied to PPU A13 for by mistake. I'm not sure how that would fix the PRG issue but it did. All checksums are matching and the game works.

lidnariq
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Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Akira TC0190 questions

Post by lidnariq » Wed Feb 12, 2020 11:08 am

Ice Man wrote:
Wed Feb 12, 2020 7:40 am
pin 31 and pin 35 of TC0190 are tied on Akira.
Are they also tied to ground? Or does "31-to-35" seem to be an alternative to "35 grounded" ?
I had PPU /OE tied to PPU A13 for by mistake. I'm not sure how that would fix the PRG issue but it did.
What are you using to test the repros? At the very least, the Kazzo ties both PPU and CPU address and data buses together—including PPUA13 and CPUA13—and just uses PPU/A13, PPU/RD, PPU/WR, M2, /ROMSEL, and R/W to control access to each bus.

FrankWDoom
Posts: 243
Joined: Mon Jan 23, 2012 11:27 pm

Re: Akira TC0190 questions

Post by FrankWDoom » Wed Feb 12, 2020 11:08 am

FYI famirom will split bins for situations like this. NES afterburner and action 52 are the other ones I can think of off the top of my head.

Ice Man
Posts: 546
Joined: Fri Jul 04, 2014 2:34 pm

Re: Akira TC0190 questions

Post by Ice Man » Wed Feb 12, 2020 11:56 am

As for pin 31 and 35, they're tied to GND as seen here:
http://bootgod.dyndns.org:7777/profile.php?id=1561

I'm testing my repros using the original Famicom console but dumping the cart using sanni's carteader so I can compare the CRC of PRG and CHR with FamiROM to make sure all bytes are equal.

lidnariq
Posts: 9766
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Akira TC0190 questions

Post by lidnariq » Wed Feb 12, 2020 12:18 pm

Sanni's cart reader makes the same assumption:
https://raw.githubusercontent.com/sanni ... matics.png

krzysiobal
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Location: Poland

Re: Akira TC0190 questions

Post by krzysiobal » Tue Feb 18, 2020 2:32 pm

Pin 31 is the true GND in that chip because a bold track goes to it.
The track from pin 20 goes to a via and then out of the board (probably for gold-plating) and nowhere else.
But after desoldering pins 20 and 31 I can confirm that they are connected internally inside chip so both are GNDs.

Pins 35, 36 are connected to GND in that board, but after desoldering them I don't measure any internal connection between them and any other pin inside the chip (NC)

All PRG & CHR pins are confirmed to work as described on wiki.

Lo-Res
Posts: 8
Joined: Fri Jul 10, 2020 3:02 pm

Re: Akira TC0190 questions

Post by Lo-Res » Fri Jul 10, 2020 3:32 pm

can somebody post the eprom wiring for this cart? I'd like to translate this cart too and I will be using a 256k 27C020 for the PRG and 2x 128k 27C010 for the CHRs

This is the only game I don't know how to wire up :(

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