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electrotrains

In development - SD card based Multicart

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I have now built the first copy of the finished version. Seems to work perfectly, and fits in a grey atari cartridge case (after a bit of snipping and filing). Pics attached (there is a reset button, but I took these photos prior to soldering it on).

 

I will open a pre-orders and technical thread in a few days.

 

Regards,

 

Robin

 

Do we have an estimate on cost at the moment?

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Do we have an estimate on cost at the moment?

 

The parts cost is around £45. I need to sit down with a calculator and work it properly. This would be reduced by £3 if I ordered the PCBs in bulk. The FGPA is the main bit of the parts cost (£22) - I imagine these will get cheaper over time (its a new product, and still engineering samples). I guess ordering some of the other parts in quantity might also reduce by couple of pounds.

 

The first board took several hours to assemble - I imagine that can probably be reduced a lot, when I get better at it, and using two types of solder paste with different melting points so i can do both sides of the board in an oven, rather than having to hand solder.

 

So.. probably in the £65 - £70 range.

Edited by electrotrains

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After hacking and filing and spraying a gray cartridge case, this is the result....

 

Label is too small (and stuck on with blu-tac!) but otherwise looks pretty good.

I'll make some proper glossy labels next week.

 

Any comments on the design?

 

 

 

post-41252-0-67336300-1439744253_thumb.jpg

post-41252-0-97608600-1439744303_thumb.jpg

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It looks wonderful, but I have one question. Will it fit in an 800 and allow the cartridge door to close?

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It looks wonderful, but I have one question. Will it fit in an 800 and allow the cartridge door to close?

 

I'm not sure - I don't have a 400/800.

 

How much space is there to spare beyond the top of a grey shell? Any chance you could meaure for me?

 

EDIT - I had no idea these existed, but might be a workable solution for 400/800 - search for "short sd adapter" on amazon.

 

I'm also not sure if the phi2/ras signal on the atari 400/800 will work with my cartridge - isn't there an issue with this on The!Cart?

 

Robin

Edited by electrotrains

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I'm not sure - I don't have a 400/800.

 

How much space is there to spare beyond the top of a grey shell? Any chance you could meaure for me?

 

EDIT - I had no idea these existed, but might be a workable solution for 400/800 - search for "short sd adapter" on amazon.

 

I'm also not sure if the phi2/ras signal on the atari 400/800 will work with my cartridge - isn't there an issue with this on The!Cart?

 

Robin

It's a little difficult to see a measurement when the door is closed, but I placed a bolt with a 10mm head on a standard brown metal back Atari cart and it fit. The door will *almost* close with a 14mm bolt. I'd say there is 12 or 13mm clearance above the brown style cart. I don't have any grey XE carts to test with.

 

Please note that my 800 does not have the metal shield in the cart door, and I placed the bolt to the left side of the cart in the approximate location of the SD card.

 

Hope this helps.

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I've just compared a brown style and a grey cart - and the grey cart is perhaps 1-2mm longer.

The SD card extends 9mm beyond the top of the grey cart shell.

 

So that looks like you need maybe 10-11mm of clearance - It looks like it should probably be ok. Which is lucky!

(and these shortened micro sd adapters are another possibility too - but probably a last resort).

 

Robin

 

EDIT

Note - I'm planning to sell these uncased (but with the label). So you could always attempt to fit in a brown case if that was preferable anyway.

Edited by electrotrains
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I'm planning on buying a couple, and I already have the micro SD to SD adapter from a Raspberry Pi project, so I'll be able to test.

 

If you are familiar with the Model A and B Pi, the SD card sticks out quite a bit, but with the Micro SD adapter it's basically flush.

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Hi All,

 

I thought I'd post to announce my new hardware project - I'm building an SD-card based Multicart.

 

https://youtu.be/PjkCTXqirv8

 

Although its far from being finished, it already shows the available ROMs/CARs on the SD card on an Atari menu, and will then reboot to the selected cartridge. At the moment it only supports 8k ROMS and 8-mbit Atarimax ROMs, with bankswitching etc, but I plan to support all cartridge types soon.

 

Adding a new ROM is simply a case of copying a new file to the SD card - no more flashing ATRs etc.

 

Not sure if there's any other available hardware that currently does this? I don't have an SIDE or MyIDE.

 

The hardware is a Altera Max 10 eval board, with my 3.3v cartridge breakout board attaching it to the atari. There's an external 1 megabyte SRAM which cartridges are copied to. Initially the atari boots to a small 8k boot ROM which is stored in dual port memory on the FPGA. The FPGA is also running a soft-cpu to copy files from SD card to SRAM.

 

I'm planning to make a PCB for this next, with the aim of fitting inside a standard cartridge case. Never done an FPGA board before, so that may take me some time. The boot ROM is also far from finished - I'm having to learn 6502 from scratch.

 

There are some other possibilities for this too - the same cartridge could be re-programmed e.g. as an atari co-processor/accelerator board. I'm planning to leave a JTAG/USB Blaster header on the board to make this easy.

 

Robin

 

attachicon.gifultimate_cart_prototype.jpg

 

This is a very cool sounding project. Please reserve two of them for me. Just let me know how much and paypal account info.

 

Stephen J. Carden

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The parts cost is around £45. I need to sit down with a calculator and work it properly. This would be reduced by £3 if I ordered the PCBs in bulk. The FGPA is the main bit of the parts cost (£22) - I imagine these will get cheaper over time (its a new product, and still engineering samples). I guess ordering some of the other parts in quantity might also reduce by couple of pounds.

 

The first board took several hours to assemble - I imagine that can probably be reduced a lot, when I get better at it, and using two types of solder paste with different melting points so i can do both sides of the board in an oven, rather than having to hand solder.

 

So.. probably in the £65 - £70 range.

what if you shipped me a 'kit form' version. all the parts, and the board, but I had to solder it myself. I can solder SMD down to 0402 if I'm patient enough, and pin pitch down to .65mm. Maybe even smaller, but I haven't had the opportunity to try.

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what if you shipped me a 'kit form' version. all the parts, and the board, but I had to solder it myself. I can solder SMD down to 0402 if I'm patient enough, and pin pitch down to .65mm. Maybe even smaller, but I haven't had the opportunity to try.

 

Joey,

 

Its probably easier (and cheaper) in that case for you to just buy the parts yourself in the U.S. All you need is the components, the PCB and a USB Blaster to program the FPGA. I will be happy to help along with way with advice if needed...

 

The PCBs cost $30 for 3 from OSH park, so you could make one for youself and sell the other 2.

 

I'll post up all the necessary files on github probably this week.

 

I'm using 0805 for the small components, but the pitch of the FPGA is 0.5mm.

 

Robin

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Joey,

 

Its probably easier (and cheaper) in that case for you to just buy the parts yourself in the U.S. All you need is the components, the PCB and a USB Blaster to program the FPGA. I will be happy to help along with way with advice if needed...

 

The PCBs cost $30 for 3 from OSH park, so you could make one for youself and sell the other 2.

 

I'll post up all the necessary files on github probably this week.

 

I'm using 0805 for the small components, but the pitch of the FPGA is 0.5mm.

 

Robin

$30 for 3 PCB? sounds a bit high. multilayer? or just 2-layer?

 

EDIT: you might want to take a look at iteadstudio, I know someone who has used them in the past and I think he said the prices were good. I don't know exactly what size of board you need, so I didn't try to estimate cost. Also keep in mind you can 'panelize' the PCBs if a larger size gets you a better price per board.

Edited by Joey Z

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0.5mm pitch is ok to hand solder by dragging then using braid. Easier than 0402s!

yes, 0402 are a pain without microscope and very fine tweezers. For that matter, still a pain with a microscope. You can do it with just a good magnifier though.

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$30 for 3 PCB? sounds a bit high. multilayer? or just 2-layer?

 

EDIT: you might want to take a look at iteadstudio, I know someone who has used them in the past and I think he said the prices were good. I don't know exactly what size of board you need, so I didn't try to estimate cost. Also keep in mind you can 'panelize' the PCBs if a larger size gets you a better price per board.

 

2-layer.

 

I'm using OSH park because they have good enough tolerances to put soldermask between the pads of a 0.5mm pitch qfp.

I know that dirtypcbs (while cheaper) have slightly less good tolerances and I've read that you end up without soldermask between the pads at this pitch.

It might not be strictly necessary to have this, but I wanted to take as few risks as possible, since this is already not an easy soldering job.

 

Robin

Edited by electrotrains

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After quickly reading a few forum posts, it looks like itead and seeed studio both lack the fine tolerances of OSH park, and can't get soldermask between the pads of the fpga. I'm not sure how important this is, and if you wanted to try a cheaper manufacter, feel free.

 

I think I'm going to stick with OSH park though. They seem to be widely regarded as making the best quality boards, they have a gold finish by default (which costs more from the others), and they have good customer service (they are USA manufactered boards).

 

Robin

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canvas opinion on how many would be genuinely interested

open a "poll" in the thread

 

 

  • not interested
  • interested
  • would buy

 

I'm DEFINITELY interested, chaps and

PROBABLY would buy.

Genius - good luck with the wizardry.

 

8Bit Baz

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