Making a cart from scratch...

Are you new to 6502, NES, or even programming in general? Post any of your questions here. Remember - the only dumb question is the question that remains unasked.

Moderator: Moderators

the_wizard_666
Posts: 32
Joined: Thu Feb 25, 2021 2:46 pm

Making a cart from scratch...

Post by the_wizard_666 » Thu Feb 25, 2021 2:52 pm

First post! Huzzah!

Anyway, I've recently taken to making repros, and am looking at making a few from scratch rather than using donors (which can get prohibitively expensive for some games). I've managed to source everything for a rate I'm happy with except for one thing - the lockout chip. A batch of them is gonna cost me more than the boards, so I don't feel like that's a worthwhile expense. Can anyone help with a supplier, or possibly a chip type and code that I can use to make them myself? Not really sure where to look, and I'm only getting the same three links every time I search. Thanks for the help!

User avatar
poorstudenthobbyist
Posts: 231
Joined: Fri Jun 24, 2016 4:20 pm

Re: Making a cart from scratch...

Post by poorstudenthobbyist » Thu Feb 25, 2021 3:03 pm

Check out this forum thread:

http://forums.nesdev.com/viewtopic.php? ... 7&start=15

The only barrier to entry is a programmer that can program the ATtiny13. I use a GQ-4x4 but that's at least $100.
Check out my website for NES, SNES, and Genesis tutorials here. And visit my store for some custom tools and boards for making games here.

You can also follow me on Twitter for infrequent updates and bad jokes!

the_wizard_666
Posts: 32
Joined: Thu Feb 25, 2021 2:46 pm

Re: Making a cart from scratch...

Post by the_wizard_666 » Thu Feb 25, 2021 3:25 pm

Awesome! So how can I tell if my programmer can do the job? And is there a functional difference if I were to use an ATtiny13A chip instead of an ATtiny13? I'm basically trying to learn this on the fly, so finding the exact details is like a needle in a haystack :P

EDIT: So according to the documentation on the burner I ordered, it supports the ATtiny series, so I assume I'll have no problem. The only question now is whether the 13A is acceptable or not for an NES cart...sounds like 13 and 13A are pretty close in specs, but I don't wanna order a crapton of chips I can't use :P

User avatar
poorstudenthobbyist
Posts: 231
Joined: Fri Jun 24, 2016 4:20 pm

Re: Making a cart from scratch...

Post by poorstudenthobbyist » Thu Feb 25, 2021 5:30 pm

I use 13A, but they're nearly identical with a few inconsequential changes.
Check out my website for NES, SNES, and Genesis tutorials here. And visit my store for some custom tools and boards for making games here.

You can also follow me on Twitter for infrequent updates and bad jokes!

the_wizard_666
Posts: 32
Joined: Thu Feb 25, 2021 2:46 pm

Re: Making a cart from scratch...

Post by the_wizard_666 » Thu Feb 25, 2021 5:43 pm

Awesome, that's just the confirmation I needed :) Now all I need to figure out is the labels, which is basically finding the right paper and restocking my toner cartridges (don't really want black & white labels :P ).

Thanks for the help man!

User avatar
poorstudenthobbyist
Posts: 231
Joined: Fri Jun 24, 2016 4:20 pm

Re: Making a cart from scratch...

Post by poorstudenthobbyist » Thu Feb 25, 2021 5:46 pm

No problem! Good luck!
(Labels are the worst part lol)
Check out my website for NES, SNES, and Genesis tutorials here. And visit my store for some custom tools and boards for making games here.

You can also follow me on Twitter for infrequent updates and bad jokes!

the_wizard_666
Posts: 32
Joined: Thu Feb 25, 2021 2:46 pm

Re: Making a cart from scratch...

Post by the_wizard_666 » Thu Feb 25, 2021 6:15 pm

Yeah, especially when you need to buy three separate toner cartridges for the printer (recently replaced the black or it'd be even more brutal). Bloody things are around $75 CDN each. At least the lamination is easy enough, although I'd probably want to do two sheets back to back to maximize efficiency. I'm buying enough supplies to make 20 carts. Should be enough for personal use plus a few for friends. Can always order more parts if it goes well.

And don't worry, I absolutely refuse to make repros of games that were commercially released here. I can't in good conscience add more fakes to the market. Just translations, hacks and homebrews here.

the_wizard_666
Posts: 32
Joined: Thu Feb 25, 2021 2:46 pm

Re: Making a cart from scratch...

Post by the_wizard_666 » Tue Mar 09, 2021 10:57 pm

So I have another newbie question. A few of the boards I ordered are VRC2/4 compatible, but unlike the rest of my boards, they don't include mapper chips. Is there somewhere to find the code for the mappers? I'd rather not have to resort to cannibalizing carts to get the mapper chips...I mean, I went with new parts to avoid doing that in the first place :P

lidnariq
Posts: 10435
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Making a cart from scratch...

Post by lidnariq » Wed Mar 10, 2021 12:20 am

VRC2&4 had third party clone ICs made, which you can sometimes find as part pulls or New Old Stock. But for more specifics it'd help if we knew what circuit board you have.

the_wizard_666
Posts: 32
Joined: Thu Feb 25, 2021 2:46 pm

Re: Making a cart from scratch...

Post by the_wizard_666 » Wed Mar 10, 2021 2:34 pm

I ordered from Muramasa Entertainment, these are the boards in question:

https://www.muramasaentertainment.com/p ... rom-basic/

His MMC1 and MMC3 boards came with the mapper chips, but the VRCs don't. Basically looking to either burn my own mapper chips or find a source that doesn't involve cannibalizing carts if at all possible.

lidnariq
Posts: 10435
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Making a cart from scratch...

Post by lidnariq » Wed Mar 10, 2021 2:54 pm

Ok, standard DIP40 ones. You might be able to find New Old Stock or part pulls by looking for:
VRC2: 23C3662, AX-40G, 23C269, AX5705
VRC4: AX5208P, AX5208C, V4

Otherwise, making a programmable logic clone is going to be fairly involved or involve obsolete parts that may be expensive and/or hard to get.

the_wizard_666
Posts: 32
Joined: Thu Feb 25, 2021 2:46 pm

Re: Making a cart from scratch...

Post by the_wizard_666 » Wed Mar 10, 2021 4:11 pm

Well, after searching for NOS on all of those, I've found one of the VRC4 chips, for $16 US per chip. Being Canadian, that'll be over $20 each. It's probably still my best bet, but I'd be remiss if I don't at least inquire about the process of how to make one myself, as if it's something I can do cheaper, I'd prefer to do that. If the process is too much, that's fine, but at least I'll know I looked into it before settling on a greater expense. Either way, I do appreciate all the help y'all have already provided!

lidnariq
Posts: 10435
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Making a cart from scratch...

Post by lidnariq » Wed Mar 10, 2021 4:43 pm

Well, if NOS or part pulls are that expensive, programmable logic will be cheaper.

The last remaining 5V tolerant programmable logic is Lattice's LC4000 series (or Atmel's native 5V ATF150x-not-V series); you'll need something relatively big to hold a VRC4 (which holds around 110 bits of state).

If you choose any other kind of programmable logic, it'll require extra hardware to keep it from damaging (or being damaged by) the 5V supply inside the NES, which is doable, it just adds to cost and board area.

the_wizard_666
Posts: 32
Joined: Thu Feb 25, 2021 2:46 pm

Re: Making a cart from scratch...

Post by the_wizard_666 » Wed Mar 10, 2021 5:45 pm

Hmmm...I'm having trouble finding those in a DIP40 chip. Everything I find in those two series' comes up as one of the square chips with a ton of contacts around it...definitely not ideal. Also, the programmable DIP40 chips I find are not from those lines. I've only recently come into this, and while I'm not averse to learning, I have no idea where to begin to look to find appropriate specs, or even if my chip burner can burn logic chips in the first place (DIP40 will fit, but I'm not sure if the data itself requires special gear). So yeah, I'll keep looking for those chips, but if you (or anyone else) can point me toward relevant documents (as I don't have time to read through the entire wiki to sift out the relevant information...total needle in a haystack), that'd be fantastic.

I gotta say too, while I can solder well enough, and have had success rewiring and reworking repro carts, this is shaping up to be a bit more of a challenge than I thought it was. And y'know what? I'm rather liking it! I know I pretty much dove into the deep end, but for me that's sometimes the best way for me to learn. Thanks again for helping to teach this old dog a few new tricks!

lidnariq
Posts: 10435
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Making a cart from scratch...

Post by lidnariq » Wed Mar 10, 2021 7:53 pm

the_wizard_666 wrote:
Wed Mar 10, 2021 5:45 pm
Hmmm...I'm having trouble finding those in a DIP40 chip. Everything I find in those two series' comes up as one of the square chips with a ton of contacts around it...definitely not ideal. Also, the programmable DIP40 chips I find are not from those lines.
I can't think of the last time programmable logic came in DIP40s. Not in the past 20 years, anyway. There may never have been a stage after ULAs that did...

I think at best you'll find some older part in PLCC, but most likely I suspect you'll have to accept some kind of QFP.
I've only recently come into this, and while I'm not averse to learning, I have no idea where to begin to look to find appropriate specs, or even if my chip burner can burn logic chips in the first place (DIP40 will fit, but I'm not sure if the data itself requires special gear).
The Minipro programmers don't obviously support any programmable logic. Usually these things use JTAG.
So yeah, I'll keep looking for those chips, but if you (or anyone else) can point me toward relevant documents (as I don't have time to read through the entire wiki to sift out the relevant information...total needle in a haystack), that'd be fantastic.
Well... https://wiki.nesdev.com/w/index.php/VRC2_pinout is probably the only relevant one for now.

If you get to the point where you start designing the actual stuff to program in, then you might need https://wiki.nesdev.com/w/index.php/VRC2_and_VRC4 instead ...

Post Reply