😀

Project VBoot

Lookin’ good. You, my friend, are awesome.

New update!

And pic!!!!

How’s it going ?

This board has been pretty quiet lately so I didn’t think to do an update. Basically I just had two weeks of straight midterms which took a toll on me mentally. And I had a major hard drive failure and had to spend a lot of time recovering data, but it looks like I managed to recover all of my Project VBoot stuff.

As for the boards, I started assembling and discovered one problem right away – the footprint for the bus tranceiver is too narrow, so I will have to fix that. That’s what I get from using that footprint from a manufacturer instead of making it from scratch like the others. I will still be able to do board debugging, I just won’t have VB connectivity on these first boards which is fine. I figured I would have to make a revision anyway, so once I finish getting all my programs re-installed I will start back in fixing the board problems and debugging the memory. All in all this is probably one of the biggest crunches of the semester for me so sorry for the lack of updates.

I just heard about this, has anything else happened, any progress, a working prototype?

Those 2mm x 2mm connectors needs to be adjusted to fit properly, I had used one of those for my homemade eprom board. If the connector parts aren’t adjusted a little with a pin they loose connection very easily I also recall having to sand down the sides of it a little to fit in the slot. Furthermore the plastic part is shorter than an original connector so it won’t go into the slot properly unless you have an extension on the PCB that lengthens the connector piece a little.

I had a post somewhere here… *looking*

Here:
http://www.planetvb.com/modules/newbb/viewtopic.php?post_id=9727#forumpost9727

Had to add 2mm or so, so that the board wouldn’t stop the connector from going all the way in. It increases the chance of a good connection than if only part of the pins in the mating connector is inserted.

I noticed the other day that Richard H. had started selling microSD card Vectrex cartridges so I had hoped to see some thread about a finished “FlashBoy Plus SD” or something like that… Seems like there wasn’t much point in making one if this project gets finished.

I know people won’t want to hear it but development has been more or less halted because of personal stuff. And then last week I broke my wrist and had surgery so now it takes me forever to do anything on the computer. I haven’t given up on this project though.

Also, the connectors I have seem to fit snugly in the VB with no modifications. I have used other ones that I had to shave down with a dremel.

A little more of an update… I had a hard drive crash a few months ago but I was able to recover almost all of my VB work. On my first run of boards I had a problem with some of the package sizes so I had to make a new rev of the board. The new rev needs about 4-5 hours of tweaking before I send it out. In the mean time, I’ve gotten a notice from digikey that one of my critical parts is going obsolete, so I haven’t figured out what I’m going to do with that yet. I have a small stock of them so I’m planning to power through the prototype/debug stage and then dealing with that later once I have a proof of concept working. It’s also possible my ideas won’t work on the VB (it is an old design, after all) so I might have to scrap my design and redo it on an FPGA. I hope it doesn’t get to that point, my FPGA skills are rusty. 😛

The other problem I have is due to my broken wrist, I can’t solder, or even hold the iron very well. So unless I can find someone that can match my SMT solder skills and wants to work for free, I may have to wait. Ugh, this stupid wrist is turning into a nightmare.

Perhaps you can find this soon to be obsolete part somewhere else?

The part that I am talking about is the bus transceiver/level shifter. I couldn’t find many other chips that did the same thing and could shift levels between 3 and 5V. However, I’ve been reading a bunch of application notes and I should be able to directly interface 3.3V and 5V logic if I use a small (150R) current limiting resistor to protect the micro. The VB will be fine because I can drive 5V logic with 3.3V. I still need a bus transceiver because I need to be able to share the bus between the VB, micro, and two SRAMs. But those parts are much more common, so a small redesign should fix this issue and make it more future-proof.

I can already tell that this board is going to have to be larger than the size of a VB cartridge, unless I go to a 4-layer board, which will cost a lot more. I would rather stay with the 2-layer design and just make it a longer board.

Bigger board doesn’t seem like a big problem if you weren’t planning on having a shell anyway. 😉

e5frog wrote:
Bigger board doesn’t seem like a big problem if you weren’t planning on having a shell anyway. 😉

Agreed, but I know some people were talking about making custom cases so I wanted to try and make the board small enough anyway. Oh well.

…I know some people were talking about making custom cases…

Cases are for chumps. 😛

I would just make the PCB long enough to include a dedicated component-less portion on its protruding end for grabbing the cart when pulling it out of the system, to avoid any unwanted contact or damage to components.

I agree, when you have a working prototype and when you’re going to make the final board there needs to be some part to grip to get it out of the VB.

e5frog wrote:
I agree, when you have a working prototype and when you’re going to make the final board there needs to be some part to grip to get it out of the VB.

Yeah, it will definitely be long enough to grab but I didn’t think about making a section without components, that’s a good idea! It probably won’t be too much extra as far as board costs and I’ll have more room for traces which is always good.

I didn’t think about making a section without components, that’s a good idea!

Just put a VBoot logo on this component-less portion and you’ve got a nice looking donor-cart-free solution. :thumpup:

If you are cheap and don’t want to pay for the extra pcb, then you could make a “pull out ring” by bending a paperclip into a “C” shape and put two vias in the PCB to solder the paperclip to. If the PCB is at least the same size as a regular VB game then inserting should be easy, and the “pull out ring” would make removing the cart easy as pie. It would probably be easier than trying to grab onto a bare PCB, unless you routed a finger hole into the exposed PCB.

mbuchman wrote:
If you are cheap and don’t want to pay for the extra pcb, then you could make a “pull out ring” by bending a paperclip into a “C” shape and put two vias in the PCB to solder the paperclip to. If the PCB is at least the same size as a regular VB game then inserting should be easy, and the “pull out ring” would make removing the cart easy as pie. It would probably be easier than trying to grab onto a bare PCB, unless you routed a finger hole into the exposed PCB.

Actually what I want to do is get a little rubber “grip” that I can solder to the board on the component-less section of the board. Like a rubber bar or nub that you can grip. It will face down while it’s in the VB so it won’t interfere with the cartridge slot plastic, and it would be easy to grab with your thumb and finger to pop the board out. I don’t know if I’ll find anything like that but I have an idea of what I want. These suggestions are great though, keep em coming.

Also I’m working on the board right now and for time’s sake I’m going to make the prototype fairly beefy so I can spend more time on actually getting the thing working and less time on designing the board. I can optimize that later. I’m hoping by the end of tonight I’ll have a board I can ship out and get back in a couple weeks. 😀

Oooh, pretty new screen! The design passes and I just need to add a few more decoupling caps, clean up some of the messy traces and verify the part packages and it’s ready to go to the fab house!

How will you prevent wobbling up and down if it’s a “naked” cart?

If you would add some more length, enough for it to peek out of the opening you could add a semi-circle grip cut in, like the profile of this cart:

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e5frog wrote:
How will you prevent wobbling up and down if it’s a “naked” cart?

If you would add some more length, enough for it to peek out of the opening you could add a semi-circle grip cut in, like the profile of this cart:

This fab house uses thick boards with very little to no flex. These things are built solid, trust me. When it’s in the VB it will be inside the plastic cartridge slot which will give it support and prevent it from bouncing around. The connector also has to be a good fit but I think I found some that work well (and fit tight!).

The only thing I will have to worry about with a bare PCB is ESD protection, in case someone accidentally gives the board a shock. I can make sure the board components are protected but does anyone (dogP?) know if the VB cartridge header has any ESD protection? Obviously it would be unacceptable to accidentally shock the cartridge and have it damage the VB. Perhaps I could use a conformal coat on the PCB to prevent touching the the traces/components.