Reverse engineering 161 in 1 cartridge to change Rom games

raynex · Nov 7, 2023

I'm in the bucket of "I know just enough to be dangerous" group. The soldering and physical work isn't an issue. Just the step by step process of what am I doing first, what programmer I need for all the chips, compiling files/menu (this will probably trip me up) and How and What program to use for programming. That last part is where I'm weakest cause some are no brainers (aka hold button, connect, drop file, disconnect) while others are far more involved (JTAG, to Arduino to PC or something like that). Once the step by step write up is complete, I am going to "attempt" to make one myself. Hope there's a donation jar somewhere cause if I'm successful, I'd like to thank the people who made this happen. Such an amazing project to come to life.

leonk · Nov 7, 2023

Sprinkled through this thread is all the stuff you need to know. @ack pretty much documented all the steps. Search for his name. I always jump to page 15 and move forward.

Start by ordering the cart and the programmer, and take it from there. Make the the PCB daughter board using a company like JLCPCB and components from AliExpress. When you have the tools on hand, the next step will be the actual soldering work. Without the tools, you can't do anything.

nnap · Nov 7, 2023

Funny enough, the hardest part was to solder the 2 wires to the CPLD for the 3G expansion module

rewrite · Nov 7, 2023

leonk said:
The process itself is sprinkled here and there, but there are some things that I don't think we should bother to document.; common sense stuff that anyone attempting this must first master. Like,

- how do you remove the chips or solder them back?
- what is the correct orientation for the chips?
- where are the programming pins for the CPLD?

Anyone who's soldered, programmed, assembled any PCB before will know the answer to this. Making this cart is really next level and should only be attempted by those who have done this before.

[getting off his soap box and running back down to the basement]

I... think this is an awful take. You gain nothing by gatekeeping info, and you don't help anyone learn. There's no need for that here, it doesn't help anyone.

leonk said:
I'm all for people making their own carts; this is an awesome hobby project. I anyone has a technical question about the process, I'll be more than happy to help here.

I mean, a technical question WAS asked. "I've been given a 6 pin pinout, but there are multiple 6-pin headers, which is for reprogramming the CPLDs?". Maybe it's not THE most technically deep question in the world, but it's entirely valid. Then you got on a soapbox instead of answering. Yes, chip orientation is silly, and so would trying to type out how to solder, but the question asked was deserving of an answer since there are several 6 pin headers on each board and a 6 pin pinout was given. But to be honest your statement is a little odd since you DID go on about your method for removing the daughterboards but wouldn't answer a legitimate question.

leonk said:
Let me use another analogy.. I'm good with changing oil and tires on my car, but I wouldn't even think of rebuilding the engine and transmission. What we have here is at the "rebuilding engine" skill level when it comes to PCB work.

This is a terrible take and just holds you back from becoming a more well-rounded person. How do you learn anything in life if you don't decide you are capable of learning, and then learn how to do it? If I'd had that mentality in life I'd never have learned to rebuild engines and transmissions and 1) paid out the nose for work that isn't THAT hard, and 2) missed out on an entire fun hobby.

I bought a little sports car that I got screwed on, engine blew almost immediately. Instead of scrapping it or paying the local shop 4k JUST TO LOOK, I bought the service manual, and about $800 in tools/parts, did research, learned to use them as I went, and that car's got another 100k miles on it since and runs like new. Did the transmission last summer. And I've rebuilt half a dozen other engines since.

Anyway, I certainly don't mean any ill will, I simply don't know why anyone would intentionally hold themselves back, or hold others back from learning. Basically anyone here is capable of anything given the chance, and a little guidance. Take things apart! Try to put them back together! Learn to do new things, make mistakes, it's good for you.

nem said:
Why? it's a Chinese multi cart, not some rare, one-of-a-kind thing. If people end up breaking them, who cares.

Exactly! This is a great "I can solder, but I'm hesitant with SMD" project. 3 different chip packages, really small through-hole stuff, get to work with two different programmers, it's great.

I'd intended on writing up a guide once I started the next one of these, but since @ArcadeTV is on it already, and I suck at writing and formatting things like that, I'm incredibly excited to see his come out!

pluger · Nov 7, 2023

leonk · Nov 7, 2023

Misos · Nov 7, 2023

pluger said:
pro'skit ss-331 desolder station
https://www.amazon.com/dp/B0BYSKPJQX

This brand of desoldering station uses a type of nozzle that is a little bit too wide to fit safely between the pins of the stilt chips.
I would recommend a Yihua or WEP station. It uses a nozzle with a flat base and a thinner tip that barely fits between the pins.

Rom1 · Nov 7, 2023

Misos said:
This brand of desoldering station uses a type of nozzle that is a little bit too wide to fit safely between the pins of the stilt chips.
I would recommend a Yihua or WEP station. It uses a nozzle with a flat base and a thinner tip that barely fits between the pins.

You are right. Even the 1mm nozzle is too big.
You can rework the nozzle using metal file and it should be ok.

darknezz19 · Nov 7, 2023

Misos said:
This brand of desoldering station uses a type of nozzle that is a little bit too wide to fit safely between the pins of the stilt chips.
I would recommend a Yihua or WEP station. It uses a nozzle with a flat base and a thinner tip that barely fits between the pins.

I used one of these China stations. Handled removing the daughter board flash chips. Had it for 2 years and hasn't let me down yet. Feels like a crime for how cheap it is.

opt2not · Nov 7, 2023

Vortex said:
Forgot to mention.
I also significantly improved the quality of the PCM sound of the cartridge by throwing out the stock 3.3v (actually 3.2 volts stabilizers and installing my own in its place, adjusted to exactly 3.58 volts (the CPLDs are 5 volts tolerant while the maximum voltage on flash memory is 3.6 volts). The logic "1" level rise-up of 0.3 volts (10%), coupled with the correct (improved) timings in the CPLD, gave rock-solid stability. No more distorted or absent sounds in ANY game.

I do not intend to make any profit from my research. If the Chinese copy my work, I think we will all be happy.

Perhaps later I will compile and release a new (third) set of cartridge entirely consisting of homebrew games and other useful utilities. If you have something to share, you are welcome.

Is this similar to the PCM fix that GadgetUK put out?

View: https://youtu.be/jwHHIpLcjdE?si=ay5-o-zsCiUI7iiW

I’ve done this fix to my 120-in-1 cart and it vastly improved the music quality. Volume changes was the biggest problem.

pluger · Nov 7, 2023

Location of Jtag on 161 in 1 board

rewrite · Nov 7, 2023

pluger said:
Location of Jtag on 161 in 1 board

Thank you. I got so worked up about the idea of people not trying to embrace a culture of learning and improving I forgot to answer the question @Rg111 asked T_T

I learned about pogo pins last night while chatting with @theoddtech on the phone. And you don't have to populate those headers, you can just use pogo pins. I bought some on what looks like a chip bag clip so it'll hold itself in place (just be mindful of pinout orientation).

https://www.adafruit.com/product/5433

pluger · Nov 7, 2023

rewrite said:
Thank you. I got so worked up about the idea of people not trying to embrace a culture of learning and improving I forgot to answer the question @Rg111 asked T_T

I learned about pogo pins last night while chatting with @theoddtech on the phone. And you don't have to populate those headers, you can just use pogo pins. I bought some on what looks like a chip bag clip so it'll hold itself in place (just be mindful of pinout orientation).

https://www.adafruit.com/product/5433

I have soldered on the back of the pcb

ack · Nov 7, 2023

rewrite said:
Thank you. I got so worked up about the idea of people not trying to embrace a culture of learning and improving I forgot to answer the question @Rg111 asked T_T

I learned about pogo pins last night while chatting with @theoddtech on the phone. And you don't have to populate those headers, you can just use pogo pins. I bought some on what looks like a chip bag clip so it'll hold itself in place (just be mindful of pinout orientation).

https://www.adafruit.com/product/5433

You can also use a male dupont connector with the pins (not soldered) in the holes at an angle so they are touching the sides of the holes.

rewrite · Nov 7, 2023

ack said:
You can also use a male dupont connector with the pins (not soldered) in the holes at an angle so they are touching the sides of the holes.

Ahhh, see, this is smart. I soldered wires on one, then decided it was quicker to solder connectors onto each header and put a connector on the programmer wires and plug and play. Leave the connectors on in case I ever needed to re-program.

But this and the pogo ones are great ideas that save a ton of time/work. If I hadn't already paid for the pogo things I'd just use the dupont lol.

GumGum · Nov 8, 2023

@ArcadeTV Would it be possible to create submenu for Hack version of certain games?
Something like, choose the game, if the game has HACK variation then just display it out on screen

rewrite · Nov 8, 2023

@ack you had mentioned that some update on VTXCart changed the sizing of things enough to afford the entire library on your dual daughterboard.

Is this update reflected in the python version, but not the exe as of the current github release? Perhaps @Fluffy can answer?

With an identical gamelist:

If I run _run.bat I get "Error: ROM\crom is full!"

If I run _run_py.bat I do not (and I've peeked at the code, it IS capable of providing the error).

ack · Nov 8, 2023

rewrite said:
@ack you had mentioned that some update on VTXCart changed the sizing of things enough to afford the entire library on your dual daughterboard.

Is this update reflected in the python version, but not the exe as of the current github release? Perhaps @Fluffy can answer?

With an identical gamelist:

If I run _run.bat I get "Error: ROM\crom is full!"

If I run _run_py.bat I do not (and I've peeked at the code, it IS capable of providing the error).

Check the comments in the bat file. Enabling 3G crom support requires the 'c3g' argument be added when running vtxcart.exe.

rewrite · Nov 8, 2023

ack said:
Check the comments in the bat file. Enabling 3G crom support requires the 'c3g' argument be added when running vtxcart.exe.

Thank you. I missed this entirely. Thought enough to dig into the python file, but not the bat....

GumGum · Nov 8, 2023

also does anyone still remember about the very cool menu UI/HUD mockup for Pick'n'Mix mode from Unibios before we have the final version?
I remember it has some cool MAI shiranui sprites, some animated background and preview thumbnail. I just could not find the video anymore

Search

Search

Reverse engineering 161 in 1 cartridge to change Rom games

raynex

leonk

nnap

rewrite

Multi Boyz Litigator

pluger

leonk

Misos

Rom1

darknezz19

opt2not

Multi Boyz Pixeler

pluger

rewrite

Multi Boyz Litigator

pluger

ack

rewrite

Multi Boyz Litigator

GumGum

rewrite

Multi Boyz Litigator

ack

rewrite

Multi Boyz Litigator

GumGum