Custom case for C64 USB floppy interface board?
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Custom case for C64 USB floppy interface board?

by nateroot on Fri Aug 06, 2010 4:56 pm

Hi all. We're looking for a custom case for a hobbyist project. We thought a laser-cut case might be the ticket.

Last year, I designed a USB->Commodore floppy drive interface called the xum1541. I've made the firmware and schematic available via GPL. My goal is to help users archive old copy-protected software before the media finally dies.

http://www.root.org/~nate/c64/xum1541/index.html

However, not many users want to build their own device, so I contacted Jim Brain. He has designed, built, and sold numerous retro-computing products. (I think the uIEC, a Commodore to SD card interface, is especially neat). He has designed the initial PCB.

http://www.jbrain.net/

Jim has gotten a lot of the layout done, but we're having trouble finding a cheap enclosure. Because the board will have connectors on 4 sides (and quite big ones at that), the standard enclosures are too deep. They would require channels cut in all 4 sides. We think we need a clamshell-style, screw-together case.

We looked at some including this one, however they're quite expensive for a hobbyist project.

http://www.polycase.com/item/rw-45.html

Is anyone interested in supplying cases? We're open to reworking the PCB layout to match a particular footprint. If so, please contact us and we can discuss the details.

Thanks,
Nate
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Re: Custom case for C64 USB floppy interface board?

by richms on Fri Aug 06, 2010 10:36 pm

Oooh, interesting.

Can it also function to make the PC appear as a floppy to a computer? I have tried several of the ones that use a parallel port, but don't really want to have to have a stoneage intel PC around to be able to use it since there is no support for that stuff in 64 bit windows 7. letalone parallel ports

Anyway, I cant see a pic of the board on any of the links, but that case doesn't seem too expensive to me - under $6 in one offs is about as good as I think you will do, or was delivery of them the problem?
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Re: Custom case for C64 USB floppy interface board?

by nateroot on Sat Aug 07, 2010 6:09 pm

Rich,

No, it does not yet have the ability for the PC to emulate a floppy drive. However, the proper signals are hooked up to do so once the PC and firmware code gets written.

I have not posted the current draft PCB because it's not final. I'm willing to send it in email to someone who is interested in helping with a case and needs to understand connectors and component layout.

We hope to sell a few hundred of these for a relatively low cost. That case would drive up the total unit cost pretty significantly (at least 20-30%). So we're looking for other options. We're open to selling this as a bare-board design, but it would be nice if there was a case option people could add easily.

Anyone interested?

Thanks,
Nate
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Re: Custom case for C64 USB floppy interface board?

by richms on Sat Aug 07, 2010 7:18 pm

That case doesn't have removable fronts or backs on it, which is normally done on cases to allow for them to machined easier. To get that volume of items with holes on 4 sides from those cases will be a pain with lots of manual handling.

For the volume you are talking, you may be able to find a case vendor that will do insert moulding where they put things in the mould that are for your cutouts so that they produce a stock case design but it has your holes in the panels. Again, I have only seen this done on removable end panels, not 2 piece cases like the linked one. But this would require you get the design down to having ports on only 2 sides of the case.

When I helped a friend do a custom device we used a case similar to these http://www.budind.com/view.php?part=pi-s and replaced the ends with some laser cut black acrylic. At only a couple of hundred cases the setup costs and delay in getting them meant that the custom holes were not going to happen. I think the break even was about 400, and that was from china.
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Re: Custom case for C64 USB floppy interface board?

by nateroot on Sat Aug 07, 2010 8:59 pm

Thanks for the advice, Rich. I'm not sure how Jim plans to manufacture it so doing the cutting on the existing RW45 case may be problematic. The current design does have connectors on 4 sides. We could get away with 2 sides but we have some optional pads for an IEEE-488 connector for future support of the original PET drives.

I think it may be best to design this for the RW45 case since it seems pretty reasonable (4.5" external, 2.75" PCB mounting posts, square shape). Then if someone wants a custom case, it could be manufactured later since it shouldn't be too hard to match this design. We could offer the RW45 with connectors cut as an option.

How does that sound?
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Re: Custom case for C64 USB floppy interface board?

by richms on Sat Aug 07, 2010 11:13 pm

IME getting things custom cut will make the case price look insignificant in comparison. Someone has to manually load them into a mill etc. The laser cut flat sheets worked better for my friend because they were able to be done somewhere else and shipped quite easily back to him and just bundled with the rest of the parts that were needed. If you are getting the cases milled out by a third party then they may have issues with you having someone else ship to them and then reshipping those items onto you.

What are the connectors that the board has other than the expected USB and large DIN plugs? Could the 488 be done on a piece of IDC ribbon to a header on the board allowing it to mount above the others on the rear panel?
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Re: Custom case for C64 USB floppy interface board?

by mikeselectricstuff on Sun Aug 08, 2010 6:34 am

Jim has gotten a lot of the layout done, but we're having trouble finding a cheap enclosure. Because the board will have connectors on 4 sides (and quite big ones at that), the standard enclosures are too deep. They would require channels cut in all 4 sides. We think we need a clamshell-style, screw-together case.


You're doing it the wrong way round.
First find a ready-made case, with as few preconceptions about shape/size as possible, then design the PCB to fit. The PCB is by far the easiest and cheapest thing to customise. Look at as many manufacturers' catalogues as possible (this is where paper catalogues really score!) - it is likely that a few will jump out as possibles.
Don't think "I need to find a case to fit my PCB" but "That's a nice/cheap/cool case, can I fit my product into it?"
Be flexible in connector types - horizontal/vertical etc. Consider IDC types with ribbon & headers to the PCB, e.g. to stack vertically on a panel.
If there are a lot of complex cutouts, think about using a PCB as a panel, as it can be cut and printed with minimal tooling costs, and you may be able to include it on your main PCB panelisation.
You can even include snap-out sections for optional connectors.

If you need to get machined holes, try to get them all on the same face - this will cut costs.
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Re: Custom case for C64 USB floppy interface board?

by Sebastian6 on Wed Nov 09, 2011 2:29 am

So, having something like a compactFlash "floppy" or smartmedia (which I think may actually work more easily, but is more expensive) If it is
possible to FULLY emulate a 1541, 1581,1571, etc. using a flash drive, then disk images could be created as partitions temporarily (separate the
multiple partitions into multiple device numbers, maybe??) and would answer all IEC drive requests, etc..so as far as the commodore is concerned, it IS speaking to a 1541, etc... just some thoughts.
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