Newbie doubts or nes reproduction

playfortoday · Post by **playfortoday** » Thu Oct 14, 2010 2:46 am

Hi everyone!
i know it has been talked a lot but due to my poor knowledge of both english and electronics i have MANY questions! hope someone could help...
Let's start with this:

I would like to have (for example) ducktales 2 for the nes.
I looked at http://bootgod.dyndns.org:7777/profile.php?id=1115
where it says:
LH231GHA Mask ROM 128 KB
CXK5864BPX-12LL SRAM 8 KB (120 ns
if i'm right the second is a RAM (not rom) so i don't have to put 2 eproms, just one, the MASK ROM.
Correct? Which game should i use as donor cart?
I was thinking about Silent Service which is a NES-UNROM too, but the sram chip is different... i mean, the size is the same, the company that made it not.
Is it ok?:/
Thank you in advance

jpx72 · Post by **jpx72** » Thu Oct 14, 2010 4:03 am

Hi!
Silent Service (http://bootgod.dyndns.org:7777/profile.php?id=438) will be ok for you to use, it has the same mapper, even the same 128KB ROM so it makes it perfect donor cart for Duck Tales 2. You don't have to worry about different writings on the chips, what's important are the parameters.
Burn the eprom with ducktales2 rom and replace the original rom in Silent Service and don't forget to do the necessary changes http://nesdev.com/NES%20EPROM%20Conversions.txt

EDIT: you can click on the PCB class name in the bootgods database to see what other games use the same board layout/type/mapper - NES-UNROM

playfortoday · Post by **playfortoday** » Thu Oct 14, 2010 4:12 am

Thank you:)

UNROM (mapper 2):
Bend up pins 1, 2, 24 and 31
Solder pin 2 to hole 22 (A16)
Solder pin 24 to GND (OE)

are these the only things i have to do or there is some implicit rule which i don't know?

Looking at the page you gave me i saw this:
CNROM (mapper 3):
No modifications nessesary
does this means i just have to put the eprom without pin bending and soldering wires? :O

jpx72 · Post by **jpx72** » Thu Oct 14, 2010 4:16 am

I've never done UNROM, CNROM or NROM cartridges, but as far as I know, Yes, no modification is necessary. I've done SLROM and TKROM according to that instructions, and everything went well

EDIT: but I hope you know about prepairing the rom for burning (cutting the header) and using exact type of Eprom. In this case you need 128KB EPROM (27C010), or the instruction would have to be modified.

playfortoday · Post by **playfortoday** » Thu Oct 14, 2010 5:41 am

i think that editing the eprom will be not a problem (at least is hope so). Anyway i'm not at that point, i'm still in the "gaghering info" part

I was thinking that, since i am a beginner, i should start with REPROPAKs... I mean, before tearing apart some good games

but hey, i have questions even here

there are two models: repropak and repropak mmc1.
I'm pretty sure that with the second i can run mmc1 games... but what about the other? there is a table on the site (http://www.retrousb.com/product_info.ph ... 1cec20bc68) that talks about 74HC32 and 74HC161. What are these? How to use them?
I have to say: this topic is really OBSCURE for me... if one good soul will explain really good how repropak works it will be really appreciated!

EDIT: I mean what do i have to do if i want to put ducktales 2 on a repropak? :S

jpx72 · Post by **jpx72** » Thu Oct 14, 2010 10:14 am

Argh read the MANUAL!
You can buy the 74*** IC's just anywhere. They represent the mapper.

playfortoday · Post by **playfortoday** » Thu Oct 14, 2010 10:26 am

yeah i know...but how to use them?i mean, i really can't understand how they work... are they filled with something? or they are just blank chips?

Post by **tepples** » Thu Oct 14, 2010 10:36 am

The 7400-series chips implement simple primitives in binary logic: AND gates, OR gates, latches, etc. You don't program them; they're like mask ROM in this respect. In this case, a 74161 is a set of four latches with a binary counter function, and the 74HC161 is the "high-speed CMOS" version of this. The AOROM, BNROM, CNROM, GNROM, and UNROM boards use the latches to store the current bank number and don't use the binary counter. The other chip is an OR gate, allowing part of the ROM to remain visible to the CPU at all times.

You'd buy a 74HC161, 74HC32, 6264 or 62256 SRAM, and a few 0.1 µF capacitors, and solder them to the appropriate spots on the board. Then you'd buy an appropriately sized 29F series flash chip, program it, and solder it on.

playfortoday · Post by **playfortoday** » Thu Oct 14, 2010 10:54 am

first of all thanks, second: i know i'm boring please be patient :/
Ok now i understand about mappers

the capacitor you are talking about must be put on the board or is optional? not a big deal, just to understand... I mean, it is expected to be there? or it is 'better' if i put it there?
Do you suggest to use flash instead of eprom? if so may i ask why?

playfortoday · Post by **playfortoday** » Fri Oct 15, 2010 4:24 am

i answer myself (i'm really sorry for the question now): the capacitors are needed, depends on which kind of cart/mapper you'll use.

playfortoday · Post by **playfortoday** » Fri Oct 15, 2010 1:32 pm

Here i am again (don't hate me).
Will this be ok to buy? any advice will be appreciated:)

Dual Powered Willem PCB3.5 Programmer

http://cgi.ebay.it/ws/eBayISAPI.dll?Vie ... 244wt_1141

3gengames · Post by **3gengames** » Fri Oct 15, 2010 10:17 pm

On NA, I've heard lots of badddddd stuff about willem or whatever. We have a programmer called the Pocket Programmer....it works well. It does upto 3pin chips, and I'm pretty sure can program over 27C040's....Never errors, okay software. Only bad thing is it's parallel port. They have a PPII and a PPIII I think, might want to look into those as they might have USB support if you need it.

In short: I recommend the Pocket Programmer.

playfortoday · Post by **playfortoday** » Sat Oct 16, 2010 12:39 am

it's just that where i live there is no real choice... i found that for a low price (including shipping). Looking outside europe is out of question, because of shipping and customs. Anyway i still look around for this pocket programmer.
If i can't find one i'll go with that willem, since it can write flash 29F010/20 too, and i think these are better than 27C010/20 because if i'm not mistaken i don't need an uv eraser...am i right?:)

3gengames · Post by **3gengames** » Sat Oct 16, 2010 8:52 am

Ahhh your going to flash? Thats fine. I'll let you know if the PP does that option. And I think I may be mistaken, I think we have a pocket programmer 2. I'll check that later and edit this.

And who knows, maybe you'll get lucky or someone released software for it that actually works good? ^_^

Post by **tepples** » Sat Oct 16, 2010 10:35 am

Why flash?

No UV lightbox needed.
Blargg is working on a solution that involves in-circuit programming on a toploading NES or a frontloader that has had its CIC neutered.