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I was thinking about if it was possible to move a whole game to another position in memory. Taking a disassembly and place that after another game and then assemble all the code again…

I have done it with some Fairchild games and it worked out very well. There’s a good disassembler for Fairchild that also replaces all the real addresses with labels instead, so you’re free to move it to any place on the memory map.

If there are absolute addressing in the Virtual Boy game it will of course not work unless these are altered.

Then you could make a menu and have it jump to the right location. This would perhaps make it possible to place all the American released games on one 128 Mbit cartridge.

It looks like it’s possible to cram four 32 Mbit eproms in one cart, when looking at the FlashBoy circuitboard.

You would have to place the smaller games inside the empty space of the large ones to make it fit, but I know nothing about how this work. I have noticed there must be some header last in the cartridge rom, how will this be affected?

Alternatively you could cram all versions of the commercial games into two carts and top them off with the nicest and most practical homebrews. The homebrews would of course be a lot easier to move anywhere on the memory-map, right?

It would be nice if someone with a FlashBoy and programming tools as well as skills could make a test. Disassemble Mario’s Tennis and Panic Bomber, place one after the other in memory, add a tiny “menu” – it doesn’t even require any graphics, just wait for button A or B, pressing A jumps to where Mario’s Tennis starts and pressing B makes a jump to where Panic Bomber starts.

Assemble all of it and try it out…

Perhaps it could even be tested with Reality Boy. I guess the final rom-image of 1MB plus menu code has to be padded to a 2MB rom and header changed appropriately to work with FlashBoy…

Mario’s has a gap from $7DC90 to $75D5F, if there was only a jump added somewhere in the beginning to that address and the menu code was “hidden” in that free space and the final rom was shortened with as many bytes as that initial jump would take you could perhaps even make it work without padding – if run in Reality Boy, or add a 1MB game as well or two more 512kB games – so you could have four games on your FlashBoy at ones – or even more if you crammed in some of those small homebrews.

Possible? Feasible?

If the roms can be freely moved around in memory it seems both possible and feasible to me. It would simplify the hardware side of making a true Multi-Cart. Just put all of it on a large eprom or bank of eproms.

The other way to go would otherwise be a large memory of some kind, most likely not an eprom as there are none large enough at reasonable cost that would hold all games. So let’s say a SD micro card – it’s small, cheap cards will easily hold all available data for the Virtual Boy and there are already finished routines to read and write to them with both PIC-processors and Atmel AVRs.

Then some kind of memory that the selected program would be copied to, perhaps the same type of eprom that the FlashBoy has or if there is large enough ram…

A menu program would be loaded into the active memory when cartridge is inserted – unless it was permanently stored in some other small memory. In the menu you would choose program – in an automated list created by the micro processor after reading the file names of the contents of the SD micro card.

Biggest problem with the second approach is speed, it will take a little time to transfer the data from the card to the eprom/ram.

Any thoughts on this, any constructive critisism?

  • This topic was modified 13 years, 10 months ago by e5frog.
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I’m going down to the city tomorrow and get one of those 2mm connectors and see if I can make it fit… if it does it will be possible to fit the PCB in the middle and have circuits on both sides.

Got it, they didn’t have it in 2×30 so I had to buy 2×40 (probably exists from other sources like farnell.com for example).
Size looks fine, hole spacing fine, I just need to check if I get a good connection with the pins in the VB without modification (other than cutting it down to 2×30).

So, either I remove the original connector from let’s say Mario´s Tennis and solder this one and see if it still works or I disassemble my VB and make a proper investigation.

Sad thing is that it’s probably still cheaper to buy a bunch of ordinary carts than to buy these connectors… On the plus side however is that it would be possible to place components on both sides.

I’ll see what I’ll do, I have a few other things that I need to do before that.

Also it’s only 4mm long so the pcb would have to extend about 1mm outside the shell – and perhaps also be shaped like the original connector to make a proper fit.

I got confirmation that the 64Mbit chip is programmable with the hardware I bought without any large fuzz.

So… I guess I need to find someone who sources the reverse tsop version as well.

Normal version is called
and the reverse is

x is the temperature rating, usually “I”.

When I was walking the dog I thought that perhaps a tool could be constructed to bend the pins the other way thereby making reverse tsops myself…

Don’t know if anyone still reads this thread but I got a price from my circuit supplier: $18.50 each…

Which would mean the eprom circuits only for one cartridge would be $148.

Is anyone really interested in a Multi-Cart for around $200?

Got a new price for 75 units: $11.00 / pcs, but where would I get $825?

I was looking at the ezoflash.com page again and apparently there’s a 128Mbit chip that can also be programmed with the Willem programmer. There has been successful tests with one particular chip that is, it’s likely others work as well.

You have to manually switch the three upper address bits and program 16Mbit at the time (fits fine with the padded VB rom images then). And there has to be a custom adapter made for the TSOP56-capsule. I have found pretty cheap socket(s) and I’m planning to make my own top board for the Sivava adapter set (http://www.sivava.com/buynow.php?pd=T10).

Currently working on a PCB, I had to make the symbols and description manually, luckily the package was already done.

There is room for 32 16Mbit slots and it will have 16 pins to switch, either I’ll do it by dipswitches – the quick and dirty way – or I’ll setup latches to hold that information and have it run by a menu… The latter would take more time of course, especially if I have to do the programming myself…

If you want to help, look for Intel TE28F128J3D, other manufacturer might work as well but the Intel version has been tested and works.

Larger chips will make things easier, and as it seems also cheaper. I saw these for $13.50 and that’s not the cheapest place to buy them – if I can find them elsewhere.

It has been recommended to me to use voltage dividers for the address-inputs in case they’re not TTL-level compatible, and it seems they are not. And level shifters for the data out – it should be possible to get a small packet of 8…

Then a 3v3 regulator and required components for that as well.

So for now it leans more to a single side of components and the usage of a donor cartridge. I guess anyone who wants a multi-cart can send a donor-cartridge and get a discount, and a larger discount for several donor carts…

To make this happen however I will need support to be able to buy all needed parts.

It would be fun to stamp the labels (label-contest!!!) with a two digit serialnumber like the original labels have their version number stamped or whatever it is (Mario’s Tennis having 19 for example).
Regarding the label I’m mostly worried about the thin material and glossy finish. Thin enough photo paper might do it – any thoughts on that?

I laid out the flash roms, needed caps, the connector and the dipswitches, put a voltage regulator there but it’s not hooked up yet and tried routing. It seems possible…

This is the pcb adapted for a new connector, haven’t checked it it fits yet though but it’s still in the planning phase so.

Anyway, it seems like it’s possible to make a 32 slot multi-cart with dip-switches.
I need to check to sort out the voltage level converting, check that I have large enough traces for the needed current and correctly hook up the regulator. But even if I need to solder jumpers manually it seems feasible.


Nice work :thumpup:

Anyway, it seems like it’s possible to make a 32 slot multi-cart with dip-switches.

So that’s 32 x 2MByte games ?

Yes, that’s correct.

so theres no way we can put roms on and off of it ourselves?

Sure, just desolder an eprom, put it in your TSOP56 adapter and reprogram it with your eprom programmer…

The PCB is quite full as it is, I’m not sure it would be possible to add support for it to be reprogrammable. Perhaps it would be possible to route VPEN and /WE to cartridge connector pins and then it would be possible to reprogram by connecting the cartridge to an eprom programmer. But I guess that’s too much work for most people and there’s no physical room for a USB-interface.

This is meant to be the whole collection in one cart.

I guess you need a FlashBoy as well.

Here’s an almost working version, the second one is for the original connector. The dip-switches I chose was apparently not in the parts library for the 3D rendering:

  • This reply was modified 13 years, 10 months ago by e5frog.
  • This reply was modified 13 years, 10 months ago by e5frog.

Paper cutouts in an original shell (yes they’re up-side-down for a better view).

I managed to squeeze in an SRAM replacement also… FerroRAM, holds the memory without battery.

Only two jumpers so far, but the regulator is still not wired properly and I guess the level shifting hasn’t been finalized yet – I have just put resistors in series with all 25 signals and also the tracks might need to be widen or thickened, I’m thinking of the ground, vcc and +5V.

Would be really neat with all games on one cart and also “sram”. It has more than double the needed ram so there’s actually nine free slots for other programs.

I’ll try and spread things more evenly and try different placements for the nonvolatile ram and try a little harder…

Does the one on the upper image have a custom cart connector? :O

Both the upper versions are for a standard 2mm 2×30 connector. The connector can be seen in the upper paper-cart-picture. I don’t know if it works yet, it looks like it could… It would help production not having to desolder connectors but cart shells are still needed so it won’t save on any carts, and as I mentioned before, the connectors are probably more expensive than getting a batch of brand new boxed cart.

I finished routing the version with ram, it looks like it’s possible.

It would be fun to have a prototype made and try it out.


Great work!

Hmm, I hope the connector works. This would be great! There must be some way to reproduce the cart shells, it’s just some plastic after all. It’d be good to to not have to destroy VB games anymore to build custom carts. How much would a connector cost if bought in a big lot?

Sure, it’s no big deal, you “just” make a cad-file of the two parts and send it to China for injection molding, there are internet-pages where you can make requests – but you need to order quite a lot to get a good price per piece. If I remember correctly they did that with some Vectrex-carts, I have the Sean Kelly multicart for Vectrex and I believe it’s newly produced. It’s close to an original but if you hold them side by side you’ll see the difference.

Also NES carts, the PowerPak is in a custom made shell.

All that is needed is someone who has a lot of money to spare. 😉

I was thinking that perhaps it would be possible to make a mold and cast the whole pcb in epoxy or similar. But that would probably also be more expensive than using donor carts.

Like someone mentioned, who needs thousands or at least hundreds of Virtual League Beaseball carts? It would be fun though to get a sealed 48 pcs box and save it for 20 years and see if it was worth more or less than today.

I bought the connector at elfa.se

One of them cost 95SEK (almost €9), if you buy 100 or more from them (which you don’t cause they are not cheap) they cost 41SEK each (€3.80). I saw 2×30 somewhere else but I can’t remember where it was… My guess is that they are cheaper anywhere else than elfa.se – it’s just convenient as they have a store downtown. It bothers me also that the VAT is not included in the prices on their webpage.

I have the Sean Kelly multicart for Vectrex and I believe it’s newly produced.

It is. Cost Sean about $20K to have the mold made IIRC

20,000? Holy cow. There must be cheaper way…

3 EUR for a connector looks like a good price to me, still cheaper than a donor cart. The problem with those is that they’ve become hard to find and much more expensive. I’ve paid at least 5 EUR per donor cart for the last FlashBoy batches and not a single one of those was V.L. Baseball. I was common japanese games and I hated destroying them.

Sh*t, that’s a lot of money.

But I guess the price per unit was cheaper than with other methods. You can order 3D-printed plastic stuff, it’s really expensive though…

Go right ahead, just upload and pay.

If I recall correctly this “musette” cost $260

You can open up a shop and sell your design to other people as well. It would be fun to see what a reasonably look-alike pair of V.B. cart halves would cost. They’re about 6,3×7,5×0,5…
If “Grey Robust” plastic material is chosen it could come out at an OK price.

Anyone good at 3D-CAD:ing?

e5frog wrote:
Anyone good at 3D-CAD:ing?

Hedgetrimmer! 🙂


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