Verifying steps needed to replace roms in cart with translation

[keropi]

Hello!

After 80sFreak gave me the idea I decided to go on and create a couple of English translated carts from Akumajou Densetsu (castlevania3) and Red Arremer II (Gargoyle's Quest II) , meaning I will take my original carts, remove the PRG+CHR roms and replace them with the transated versions  
Now for Akumajou Densetsu there is "Akumajou Densetsu (J) [T_Eng1.0_Vice]" and for Red Arremer II there is no translation, just the english Gargoyle's Quest II that are both 256kbytes so I assume it will be fine to swap roms (correct me if I am wrong  on this one...)

From what I read the steps needed are to determine what kind of rom size eproms I need , split the translated rom to PRG and CHR  , burn them and replace them on the actual carts. I will write down the steps that I *think* I need to do, please correct me when I am wrong, I will order parts when I get all "verified"  

So for Akumajo Densetsu I see here that it is made from:

PRG0  256 KB    -> I need a 2mbit eprom like the 27C020
CHR0  128 KB -> I need a 1mbit eprom like the 27C010


and Gargoyle's Quest II with info from here is made from:

PRG0  128 KB    -> I need a 1mbit eprom like the 27C010
CHR0  128 KB -> I need a 1mbit eprom like the 27C010

So assuming I get the eprom chips, split the roms with TNINES (is this the best program for the job btw?) to PRG and CHR and I successfully burn them, then:

for Akumajo Densetsu I just replace the roms and enjoy   wrong, I found info here

for Gargoyle's Quest II since it is a MMC3 game I  follow this diagram to solder the replacement eproms:


How does all that sound? Are the steps correct? Sorry for the long post and thanks in advance for any help!  

[keropi]

Yesterday I "fixed" Gargoyle's Quest 2 (still waiting to receive the 27C020 eproms to do Akumajou Densetsu...) , here are some pics for your viewing pleasure 

   

   

   

[keropi]

thanks!  next one will be better! 

[famifan]

well done. is it hard? i guess no.
keep us informed

[GohanX]

Well done!

I'll finish my Akumajou Densetsu one day! I've redone it like 3 times only to find out later after I had put it on the shelf that the 1 mb rom type I used simply wasn't compatible with FC games.

[keropi]

thanks!

well , the mod was on the easy side I guess... it helps to have a desoldering iron to remove the mask roms, else you need to cut or spend time with wick which is meh
you do need some soldering experience though because you risk damaging tracks

[MaxWar]

Nice!
I certainly would like to try doing this with Lagrange Point. But as far as i know, there is no complete translation right?

[keropi]

... and here is Akumajyou Densetsu , this turns out better 
The cart needed some internal cutting to accommodate the larger CHR eprom, luckily nothing that shows outside 

   

   

   

[GohanX]

If you don't mind me asking, what did you rewire on that CHR chip? I have some notes somewhere from where I took a multimeter to find the pinout of that chip, but you've already got it figured out! Looks like you have Pin 24 grounded, but I can't quite make out what you've done with pins 1-2 and 31-32.

[keropi]

I don't mind at all, all I did is follow the guide here: http://www.callanbrown.com/index.php?option=com_content&view=article&id=74:castlevania-iii-with-full-famicom-sound&catid=36:home-console-projects&Itemid=62

The CHR ROM is a little more complicated. Here's what you have to do:
a. Bend up pins 1, 2, 24, 31 and 32 and clip them a little bit (but not too short, you still need to solder to some of them)
b. Solder a wire into hold on the board where the EPROM's pin 24 will go
c. Now insert the EPROM and solder down all the pins that you didn't bend up
d. Solder your wire from hole 24 to pin 2 of the EPROM
e. Now solder a wire from the bent-up pin 24 to a ground. The spot I normally use is pin 16 of the EPROM which would be the last pin on the left side of the chip.
f. Finally, strip a length of wire about 1cm long and solder a wire that bridges the between pins 30, 31 and 32. This basically gets power to pin 32. Pin 31 is not connected to anything so you can solder across it just fine.

But I am actually having problems, after a while the famicom just goes to back screen. The cart works fine again if I remove it for a while.
I *suspect* that I must not connect pin31 at all since it's "Program Enable Input". Pin30 is not-connected on the datasheet so it just goes vcc to pin32. So basically I will try a connection between pin30+32 , leaving pin31 floating.
Pin1 is "VPP = Program Voltage Input" , so AFAIK it doesn't matter if it's floating...

I have made a thread on nesdev about the problem, if the solution is found I will report back 

[GohanX]

Awesome, thanks! You know, I'm keeping an eye on this thread to see if you needed any help with some of the weirder carts that I've made, and instead you are the one helping me.

Hopefully my baby takes a nice long nap and I can try it out.

[keropi]

I hope it works for you... I will do my testing tomorrow morning, don't have the proper tools at home to tinker with it , good luck 

[FrankWDoom]

I don't mind at all, all I did is follow the guide here: http://www.callanbrown.com/index.php?option=com_content&view=article&id=74:castlevania-iii-with-full-famicom-sound&catid=36:home-console-projects&Itemid=62

The CHR ROM is a little more complicated. Here's what you have to do:
a. Bend up pins 1, 2, 24, 31 and 32 and clip them a little bit (but not too short, you still need to solder to some of them)
b. Solder a wire into hold on the board where the EPROM's pin 24 will go
c. Now insert the EPROM and solder down all the pins that you didn't bend up
d. Solder your wire from hole 24 to pin 2 of the EPROM
e. Now solder a wire from the bent-up pin 24 to a ground. The spot I normally use is pin 16 of the EPROM which would be the last pin on the left side of the chip.
f. Finally, strip a length of wire about 1cm long and solder a wire that bridges the between pins 30, 31 and 32. This basically gets power to pin 32. Pin 31 is not connected to anything so you can solder across it just fine.

But I am actually having problems, after a while the famicom just goes to back screen. The cart works fine again if I remove it for a while.
I *suspect* that I must not connect pin31 at all since it's "Program Enable Input". Pin30 is not-connected on the datasheet so it just goes vcc to pin32. So basically I will try a connection between pin30+32 , leaving pin31 floating.
Pin1 is "VPP = Program Voltage Input" , so AFAIK it doesn't matter if it's floating...

I have made a thread on nesdev about the problem, if the solution is found I will report back  

The proper connection for pin 31 on a 27C020 is 5V. Pin 31 is /PGM, which means "enable programming when low". You are reading, not programming, so you want the opposite, which is 5V. Most of the time you are fine leaving it floating, but 27C101 for example will not work if it's not high.

[80sFREAK]

I hope it works for you... I will do my testing tomorrow morning, don't have the proper tools at home to tinker with it , good luck 

Neat job As about troubleshooting - check manual for exactly the chip. There is usually recommendations about Vpp and /PGM pins in read mode.

[famifan]

As about troubleshooting - check manual for exactly the chip. There is usually recommendations about Vpp and /PGM pins in read mode.

i second that. (had an issue with #PGM on old-fashioned 2764 http://www.famicomworld.com/forum/index.php?topic=7874.0 )