HD DMA Cable

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DoG
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HD DMA Cable

Post by DoG »

HD DMA Cable

I have done a small PCB so that you can make your own HD cable. Compatible with Lotharek's PCB. Thus this also works with UltraSatan (Tested with US). I don't know if it has the same pin out as Oliviers DMA cable though. I haven't tried it. I have made two different variants of the board. I have use the one with bigger holes in the instruction below. You can also use loose pins.

Big hole PCB Gerbers.
Standard hole PCB Gerbers.

WARNING: Longer cable might/probably need pull-up resistors on the data lines on the DMA. Otherwise corruption might occur. If the cable are used on a Mega STe/TT then make sure it is not shorted on the port above the ASCI port.


IDC20 Female-Female 30cm.jpg
IDC20 Female-Female 30cm.jpg (223.51 KiB) Viewed 4785 times


Parts needed:
  • One IDC 20 pin Female to IDC 20 pin Female cable in the length you want (shorter is better) or make your own.
  • Two PCB (or one if your doing a Ultra Satan cable).
  • Two 25 Pin D-Sub Male connectors for cables (or one if your doing an Ultra Satan cable).
  • Two 20 Pin IDC Male Connectors (or one if your doing an Ultra Satan cable).


How to make it:

Remove 6 pins from one side of the DB25 connector by pulling it out with a pair of pliers from the solder side. Cut away the metal housing around it. Cut by the two holes at end and it should come apart. Cut away the end plastic were you removed the pins to make the connector a 19 pin D-Sub. I have made some red lines below so you can see what I mean. Sand it if you want it it to look nice.

D-Sub 25 and how to cut.jpg
D-Sub 25 and how to cut.jpg (179.22 KiB) Viewed 4785 times
Front and back of two boards with info.png
Front and back of two boards with info.png (139.44 KiB) Viewed 4785 times



Push in the DB19 you made into the PCB. It's a snug fit and it will not sit flush with the PCB. Solder the connector and then the IDC connector to the board.

Not flush with board.jpg
Not flush with board.jpg (84.44 KiB) Viewed 4785 times
IDC20 Female Cable and IDC20 Male PCB Connector.jpg
IDC20 Female Cable and IDC20 Male PCB Connector.jpg (119.93 KiB) Viewed 4785 times



Clean the board with IPA (Isopropanol), connect and try it out!

Mounted MegaST.jpg
Mounted MegaST.jpg (225.14 KiB) Viewed 4785 times
Attachments
DB19 to IDC20 Standard Holes.zip
(46.99 KiB) Downloaded 233 times
DB19 to IDC20 Bigger DB19 Holes.zip
(100.47 KiB) Downloaded 216 times
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DoG
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Re: HD DMA Cable

Post by DoG »

Just with loose pins
Just the pins.jpg
Just the pins.jpg (116.55 KiB) Viewed 4781 times



Side view
Mounted MegaST side view.jpg
Mounted MegaST side view.jpg (295.35 KiB) Viewed 4783 times
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exxos
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Re: HD DMA Cable

Post by exxos »

:bravo:
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Icky
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Re: HD DMA Cable

Post by Icky »

Nice :thumbup:
DominoTree
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Re: HD DMA Cable

Post by DominoTree »

This is WAY cleaner than what I hacked together :lol:

One suggestion - if you mount the "Dsub19" port on the PCB edge (half the pins on top pads, half on bottom) the footprint becomes smaller and it'll work better with old Megafile drives (where the power cable is directly above one of the DMA/ACSI ports)

Yours *might* actually still clear it though, it looks more compact than most of the ones I've played with.
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DoG
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Re: HD DMA Cable

Post by DoG »

DominoTree wrote: Fri Jan 08, 2021 8:43 pm...One suggestion - if you mount the "Dsub19" port on the PCB edge (half the pins on top pads, half on bottom) the footprint becomes smaller and it'll work better with old Megafile drives (where the power cable is directly above one of the DMA/ACSI ports)...
You mean SMD pads and then on the edge? Sure. I can do that too and put it in this thread. I initially read this post wrong and did this instead... :roll:

Gerbers for tighter PCB

Front and back tight.png
Front and back tight.png (81.38 KiB) Viewed 4730 times
DB19 to IDC20 Bigger DB19 Holes Tighter.zip
(100.26 KiB) Downloaded 231 times
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DoG
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Re: HD DMA Cable

Post by DoG »

Made this a few days ago. Forgot to post it. I have ordered the PCB so it will take some time before I get it and can solder one up and test it. The IDC20 is underneath and DB19 connector at the end so should clear the power connector on the old Megafile better. I don't have a Megafile but I can at least test it with other stuff. So I will post the Gerber later. I think it says 2021 on the one I ordered though. ;) :shock:

Front and back edge.png
Front and back edge.png (34.69 KiB) Viewed 4661 times
DominoTree
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Re: HD DMA Cable

Post by DominoTree »

DoG wrote: Tue Jan 12, 2021 6:23 pm Made this a few days ago. Forgot to post it. I have ordered the PCB so it will take some time before I get it and can solder one up and test it. The IDC20 is underneath and DB19 connector at the end so should clear the power connector on the old Megafile better. I don't have a Megafile but I can at least test it with other stuff. So I will post the Gerber later. I think it says 2021 on the one I ordered though. ;) :shock:

Front and back edge.png
Looks about as compact as you can get :D
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DoG
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Re: HD DMA Cable

Post by DoG »

Totally forgot about this.

Here is the last gerber for edge connecting the DB19. The copper plates on the edge is moved a bit so it should be easier to solder. So image is not exactly as finished product. Tried and working on UltraSatan.

DB19 to IDC20 Edge.zip
(61.2 KiB) Downloaded 142 times
DB19-IDC20 edge1.jpg
DB19-IDC20 edge1.jpg (275.93 KiB) Viewed 4160 times
DB19-IDC20 edge2.jpg
DB19-IDC20 edge2.jpg (251.48 KiB) Viewed 4160 times
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Smonson
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Re: HD DMA Cable

Post by Smonson »

That's fantastic work @DoG. Congrats!
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