Hey,

As you know, we don’t have a link cable, or a suitable connector available for the VB. There’s several ways to make a cable that works, but in the end, it’s mostly ugly hacks for development/prototyping. I’ve been trying to come up with a way to make a quality cable that would just plug in… but so far have been unsuccessful.

So… it got me thinking… how about just making a proper cable? I contacted a custom part manufacturer (who I’ve used parts from in the past), and they said they could do it, but of course wouldn’t be “cheap”. I sort of based my design thoughts on the SNES A/V connector, which includes a plastic shell with crimp pins. So, I found some crimp pins which should work, but I didn’t have any way to make a 3D model of the plastic shell.

Well, of course I asked Hedgetrimmer (our resident 3D modeling expert), and he created a GREAT model of a plastic shell to house the pins. With that, I was able to verify with the MFG that it could be made, as well as get an estimate for price.

So, now here’s the question. They were right… it’s not cheap. A complete link cable would cost about $40, since the quantity would be so low. At this price, how many would be interested (and how many)? Would anyone want just the connector/pins?

There’d probably only be about 50 cables made, and this would probably be the only run, since I’m assuming the demand would be low. I don’t mind investing the money (and probably losing quite a bit on this project), since I think it’s a very worthwhile project… but, if I’m the only one that has any interest in it, there’s no point in even considering it further.

But, IMO this seems like a good time to pursue this, since homebrew is continually advancing, and I think linked homebrew has been held down by lack of link cable. Also, I assume some will be buying the new Flashboy, even though they already have an old Flashboy… so with two flash carts, why not have a cable to link the systems?

Of course, if there’s an unanticipated large interest in this, the price would come down… but we’re a pretty small community, and the homebrew crowd is really the only market for this.

Thanks,
DogP

I can’t get over how awesome these are.

morintari wrote:
That is if you will you be able to play multi-player games (greater than 2 player) using the usb link and a multi-usb hub for your computer?

Sure… there’s no reason you couldn’t use more than one USB connected to a computer, or have several connected together over the internet. Of course the games and PC software don’t exist for that yet, but there’s no reason it wouldn’t work.

DogP

Hey DogP I may be totally wrong in suggesting this but if the USB cable will allow you to do a rom dump of the game your playing. is it possible to change flash information(ie change the game your playing) w the FlashBoy while still inserted and not connecting the FlashBoy to the USB directly instead Having the only connection to the flashboy being the Link cable but still being able to change games? W/o removing the cart. If not why not?

morintari wrote:
Hey DogP I may be totally wrong in suggesting this but if the USB cable will allow you to do a rom dump of the game your playing. is it possible to change flash information(ie change the game your playing) w the FlashBoy while still inserted and not connecting the FlashBoy to the USB directly instead Having the only connection to the flashboy being the Link cable but still being able to change games? W/o removing the cart. If not why not?

It’s not particularly practical, but yeah… I’ve reprogrammed my own flash cart over the link cable. I’m not sure if flashing the Flashboy is possible like that though. It’d depend whether the flash /WE (write enable) pin is connected to the /WE on the cartridge edge (probably not, since it’s probably connected to the microcontroller on the cart).

The reason it’s not really practical is because you’re using the VB to write the flash (running the flash writing algorithms on the VB’s CPU), which means you need some sort of bootloader. It’s easy to add that to homebrew, but if you flash a commercial ROM to it, it’ll overwrite the bootloader, and you won’t be able to load it over the link cable again. You could add an extra ROM to the cart just for bootloading, or waste half of the existing flash to do it, but that’s not worth it IMO. It’s also not that fast (it’d take ~1 min to load a Flashboy). And if loading fails, your bootloader may be toast, and you’re back to where you started.

I did come up with a really small loader (48 bytes IIRC) that you could stick in a few interrupt vectors to load from the link (select by holding a button when you turn the VB on), though I never tested it, and I don’t really remember how it worked. It’d still require a modified ROM though, and still be susceptible to corruption.

Oh, and what makes this different than the ROM dumper is that you have a “boot cart” with the ROM dumper, then swap for the other cart you want to dump. You could easily have a boot cart, then swap for a blank cart to flash… but then you need two flash carts (one flashed with the boot cart code), which doesn’t really make sense.

DogP

Does that mean the system won’t explode if you remove the cartridge while it’s running (provided it’s not trying to execute from ROM space)? What happens if you attempt to read a ROM address while no cartridge is inserted?

Guy Perfect wrote:
Does that mean the system won’t explode if you remove the cartridge while it’s running (provided it’s not trying to execute from ROM space)? What happens if you attempt to read a ROM address while no cartridge is inserted?

Yeah, you gotta make sure you’re not accessing the ROM for anything, but it runs just fine without the cart. Reading it without a cart reads just like any other address that has nothing connected to it (like the expansion area, upper 8 bits of the cart RAM, etc)… just random garbage, whatever state the data pins happen to be in with no driver (no pull up/down on the pins).

The one caveat is if you insert a cart with battery backed SRAM while the system is on, the system resets. I forget exactly which pin causes it, but you can lift the pin and it works just fine. I don’t remember if it was hitting an interrupt causing the reset (which could be disabled), or if it was shutting down the system hard. I’d have to dig through my notes.

DogP

DogP wrote:
The one caveat is if you insert a cart with battery backed SRAM while the system is on, the system resets. I forget exactly which pin causes it, but you can lift the pin and it works just fine. I don’t remember if it was hitting an interrupt causing the reset (which could be disabled), or if it was shutting down the system hard. I’d have to dig through my notes.

DogP

That would be the dedicated \RESET pin 7, see Cartridge Pinout.

cYa,

Tauwasser

Tauwasser wrote:
That would be the dedicated \RESET pin 7, see Cartridge Pinout.

Yep, that’s right. I wanted to say pin 7, but couldn’t remember for sure.

DogP

Morintari wrote earlier

If payment can wait till march I’ll want a link cable and 3 USB cables. That is if you will you be able to play multi-player games (greater than 2 player) using the usb link and a multi-usb hub for your computer?

Thanks for your answer DogP But i’m also wondering if it is possible to link up multi VB’s via link cable and USB hub without a computer. Is it possible to write a program and put it on a flash drive so that it automatically executes when plugged into the hub so you could bypass the computer all together?

Count me in for 1, assuming the price is at or near the $40 target price mentioned above.

Thanks!
-Jason

morintari wrote:
Thanks for your answer DogP But i’m also wondering if it is possible to link up multi VB’s via link cable and USB hub without a computer. Is it possible to write a program and put it on a flash drive so that it automatically executes when plugged into the hub so you could bypass the computer all together?

No… if you’re using USB, this will only act as a device, not a host, so there has to be a computer (USB cable can’t talk to USB cable without a computer). You could use a small/cheap computer (like a Raspberry Pi or something similar), as long as it supports USB and you can run your own code on it.

DogP

I can’t believe I haven’t responded to this yet… Absolutely put me down for at least two– one VB<->VB and one raw cable for my own projects. My own homemade cable looks shameful compared to this. Very pro. 🙂

Put me down for a VB to VB and a USB to vb.

Can we get an update on cost per cable type and cost of individual connectors?

Do individual connectors have all six contacts or are there master/slave variants?

cYa,

Tauwasser

I’m really glad there’s still a community for this. I hope to see this used in some quality homebrew.

I’m really interested in this project – as most people are.

But, having said that (typed that ??)..I think it’s a bit pre-mature to ask for prices and talk about pre-orders and how many of what you guys want to pick up :). I think he was just showing a beta and telling people about his progress (WHICH IS AMAZING).

Way to go dogp..and big props from the ..bigmak 🙂 heh

If some of the beta cords or tests cords ARE functional (but don’t fit quite right..short cord ect…), I would love to see a way to get them into the hands of some of the developers (thunderstruck, guy perfect, danb, runnerpack..this could go on..).

Anything I can do to help dogp…just let me know.

-Eric

Tauwasser wrote:
Can we get an update on cost per cable type and cost of individual connectors?

bigmak is right about this… there’s really no way to estimate the costs right now. I just thought I owed you guys an update on the progress. To date, all prototypes have been 3D prints, which are (hopefully) more expensive (per connector) and lower quality (hopefully, as well 😉 ) than the final product will be.

Tauwasser wrote:
Do individual connectors have all six contacts or are there master/slave variants?

Eight contacts? 😉 All connectors will have all 8 pins in them, though a VB<->VB cable will have 6 wires connecting between them (connecting in the correct pinout), and of course a USB cable will only have 4. If anyone wants the raw connectors, it’ll just be a shell and pins (you can choose your own cable type and number of wires).

bigmak wrote:
I would love to see a way to get them into the hands of some of the developers (thunderstruck, guy perfect, danb, runnerpack..this could go on..).

Yeah, once we get a final 3D printed shell design, I’m hoping to offer a few cables with printed shells to developers, so people can start playing around with it while we’re waiting for the final shells (I’d send them replacement shells when they arrive). Of course that depends on how long the final shells will take… if they’d only take a few weeks, then I’d probably just wait for them.

DogP

I’m getting in on this a bit late, but count me in for a VB to VB cable if it’s still an option. I’ve yet to convert my friends to the VB lifestyle but this may help 🙂

Great concept

Quick update… we’ve got a (hopefully) final design, that’s currently in the process of being printed (in red). As soon as that arrives (in the next week or two), I’ll check that the model matches the print and that there aren’t any remaining issues to work out… then it’ll be ready for mass production, so stay tuned.

DogP