Planet Virtual Boy

Virtual Bowling is right there in a zip-archive for download - some 300+ kB.

http://www.planetvb.com/modules/games/?r017d

The 1k file is some patch to get into the debug mode.

Looks nice!

Hope you can sort the software part out.

... or (for Minestorm) two of these types of nozzles and a heat gun (and additional pipes) or two separate heat guns...




Press the button, heat, pull apart.

I have only removed one (to send to Minestorm before I got the FlashBoy+), used a hot air gun with adjustable heat. No damage to the plastic and it took less than 5 min before the connector could easily be pulled off the PCB. You need just enough heat and be sure to move it all the time. It's no different than to desolder other stuff.

Connector plastic is of a different kind than the rest of the cart, don't know how much heat it can take. It's obviously possible to solder the connector with no damage. Maybe some foil on the plastic to protect it helps if there are any worries.

But listen to Minestorm, he's the expert, maybe better safe than sorry. Don't understand how he has the time and patience to desolder with a solder iron. With the amount of carts passing he should have some "all pins double sided heater thing-a-majigg" that warms all pins up at once and just slides that connector off.

I guess adding some flux would speed things up and decrease the risk of damaging the plastic.

EDIT: I was thinking a double pair of something like this, but wider:


So, heat all pins at once, slide the connector and board apart.

I had the Galactic Pinball cart disassembled for measurement but found DogP's site when making a quick search for the LH52A64N pinout.

Here's what he says:
http://www.projectvb.com/tech/cartpinout.html

Compared to the ROM: A0-A12 are hooked to eachother and D0-D7. So it doesn't seem that (hardware wise) it would be different from reading from the ROM but with only the lower eight bits.

Other differencies to ROM is the /WE on cart pin3, /CS1 cart pin 6, CS2 cart pin 7 (seemed to be held high).


So if I got this right...
If reading at address "SRAM" which is the first address for the SRAM's first byte you should instead of getting 16 valid bits just get eight valid bits and the rest is crap. If listing the data as bytes that's every second byte. As D0-D7 is hooked up to the sram it should be even bytes in such a data list that are valid ones, that's byte 0, 2, 4 etc...

Seems a bit odd to me.

Isn't the SRAM hooked to the same bus as the rom but only half of the data lines hooked up?

Is it the data lines that are used every second one and not just the upper or lower half?

So is the SRAM using D1, D3, D5, D7, D9, D11, D13, D15 instead of just D0-D7 or D8-D15?


Guess I could open a cart and have a look...

I'm sorry you took it that way, that's not how I meant for my little rant to be received. I started with a joke and expected the rest to be received at about that level.

I don't know what experience you have, I'd expect you to be an engineer or learning to be to start a project like this. I'm an engineer myself, studied mainly digital electronics. I'm very aware of that I don't know everything there is to know and for almost every project I'm in I learn new things from older co-workers. "We just used to do like this when I was working at... " here or there. Maybe it's a very simple solution that is quick to implement.


Quote:

My interpretation is that you weren't familiar with the way to make a battery backup and I thought I might as well present the solution for you and all other people reading (or I would have sent it as a PM) so you/they wouldn't have to google for it. Nowadays a flash rom is usually what you find in stuff.

I thought there was a problem, I wanted to offer a solution. Not trying to push you down or claim I know more or that I'm better than you - I wouldn't attempt this project myself as there are too many details I'm not familiar with.

BTW, if you were already familiar with the battery solution, why hadn't you hooked a battery there already to be able to debug it when it's not live?


[joke]
I tried explaining it to my five-year-old daughter, she didn't get it, not even when I translated it into Swedish, I think you'd need to be at least 10 with some basic electronics knowledge.[/joke]

I think any normal person who had plans to make some type of multi-cart for the Virtual Boy would wait and see where this goes first as it's the best solution anyway. I didn't think it was any idea to do any more work on a static multi-cart if there's one coming up that reads it from a microSD card or similar.

Regarding Minestorm's probable already finishing a cart, I just meant that as he has done many parts/blocks of such a project already it would be easier for him to put those together (I'm guessing) and that you shouldn't be deterred to keep at it even if it takes time as you're starting from scratch. If you want to make a similar project for another console you already have a base and wouldn't need to start all over again - so next time would be quicker. Not that there's any hurry, as Minstorm said - it's for fun, and I hope it's still fun for you at times. The boring part comes after a bunch of carts when you're just building and delivering the stuff.

I'm sure several people here, some other people who has found your blog and also including myself is quietly cheering for you and your effort so far and hope you'll stay at it and offer us the last cart we will ever need for the Virtual Boy.

So nothing negative was meant on my part. I'm not afraid to write very clear if I mean to be evil/pissed off/grumpy/etc.

I usually try to be cheerful and helpful online and I hope everyone who reads my messages has that as an initial point of view. I hope noone who has some history with me at this or other forums thinks anything else.

So all my best to you, if you want some pointers or help, don't hesitate to ask us other engineers here.


Anyway, back to the PCB-plant, "holding my thumbs" that you'll be able to solve all little problems you run in to. I think we know how it can be when you wrestle with a single little annoying detail for weeks - better to have it sorted out before it's done, debugging can be even more time consuming.

What, are you spending your own money!!?? ;-)

If you're short on cash perhaps asking for donations alternatively some kind of kickstarter project or maybe pre paid orders would help.

Of course it's a lot of work if you haven't done it before, that's always the case. Not just the hardware which can take a long long time to CAD when you've found the parts you need but all the software as well.

If you weren't making one I'm sure Richard would have made one by now as he already have most parts of such a project done with FlashBoy and also his Vectrex cart with microSD card reader. I don't think the market is that big so you probably need all of it yourself if you want to make something from the invested time and money.


Regarding the SRAM issue, already in the 70's (maybe earlier) they used a battery and two diodes, it should still work... Diode prevents current to flow into the battery, a current limiting resistor could be added to prevent smoke and melting things if there's a short...

You need a second diode for board VCC to block the battery from powering the whole board.

VCC of SRAM ----|<---- board VCC
VCC of SRAM ----|<---- battery +

GND of SRAM ------------------------ battery -

I was considering using something similar in my Fairchild carts but I decided to try out FeRAM instead which worked out pretty well although they are quite expensive. I saw a RAM cartridge (game copier) for Commodore 64 that worked the same way, holding the memory with a battery.

This should hold the SRAM powered for a LOOONG time (if it's a 5V SRAM)
http://se.farnell.com/productimages/farnell/standard/42245229.jpg


So what can we do to ramp up your motivation? Not that I have the money right now to get one of these so on my account you can work on it a few more months. ;-)


I was thinking if it would be possible to use the CAD:ed connector by one of our members and then try to find the female end of a PCMCIA connector (only the metalpieces that are in the connector) to make proper connectors. The type you have previously linked to worked most of the time on my veroboard built eprom cartridge but it would be nice to have something original looking that works all the time, even if you happen to bump the cart.

Richard, who made the most excellent FlashBoy and also VecMulti among other things ( http://www.vectrex.biz/ ) refrained from making an SD card based cart because of this project, so lets hope Vaughanabe13 gets this together soon, preferably when I happen to have money to buy one. ;-)

If you get tired fast then a cart with everything on it is a good thing but if you play the same game for a long time I don't see anything negative with having just one game at the time.

So, what kind of mod is planned?