PDS DOS Compatibility Card Extender

alxlab

alxlab

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Does anyone have one of these Reply DOS compatibility card extenders?

1636498605822.png


I'd like to make a clone and possible one with 2 normal DB15 connectors for the joystick and monitor if they will fit. Want to know the PCB dimensions.

tomytronics on reddit seems to have made a clone but I don't see any project files related to it on the nets.

1636498741878.png


I'll ping tomytronics on reddit too.
 
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Patrick

Patrick

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interesting copy right on there.

is it so it can work in like the Q700 type case design ?
 
warmech

warmech

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Been looking for one of these for a while now; never saw that reddit post, though - I hope they respond! I'd love to throw my DOS card into something other than the 6100 it's in now.

Patrick said:
interesting copy right on there.

is it so it can work in like the Q700 type case design ?
Click to expand...

Yep!

The dumb thing, in my opinion, is that they (the OEM, not the guy that made the new one) could have just put the necessary ports on the other end of the extender and eliminated the need for the unobtanium cable and yet they didn't. I get maintaining compatibility of a sort, but those high-density DA26 connectors are NOT cheap - I think the one I bought for my homemade cable was $12-14 USD, versus the tens of cents I paid for the accompanying DA15 connectors.
 
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alxlab

alxlab

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Yeah exactly why I thinking can probably put two db 15 connectors on the extender. I understand why they put the HD-26 connector on the extender since it's expected that if you got the card then you would have the cable as well. As time goes on though the cables are thrown away and just the cards remain. Same story for the HDI-45 to DB-15 adapters.

The HD-26 connectors aren't that expensive. You can still get them on Aliexpress for less than a buck:

Through hole version
Solder cup
Connector and housing
Cable with M/M

I was also planning to make a breakout box that you would use a HD-26 cable with M/M ends and then the box would have DB-15 video pass through, DB-15 video out and DB-15 joystick port. That way you can just use standard DB-15 cable instead of having to start splicing stuff.
 
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warmech

warmech

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alxlab said:
Yeah exactly why I thinking can probably put two db 15 connectors on the extender. I understand why they put the HD-26 connector on the extender since it's expected that if you got the card then you would have the cable as well. As time goes on though the cables are thrown away and just the cards remain. Same story for the HDI-45 to DB-15 adapters.

The HD-26 connectors aren't that expensive. You can still get them on Aliexpress for less than a buck:

Through hole version
Solder cup
Connector and housing
Cable with M/M

I was also planning to make a breakout box that you would use a HD-26 cable with M/M ends and then the box would have DB-15 video pass through, DB-15 video out and DB-15 joystick port. That way you can just use standard DB-15 cable instead of having to start splicing stuff.
Click to expand...

Sweet deal! I've just got mine from Mouser (mostly because I can just drive 20 minutes and pick them up from their will call), but this is a bit better long-term solution.

I'm also working on a breakout board with almost exactly that same approach, so it's good to know I was probably barking up the right tree!
 
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Ron's Computer Videos

Ron's Computer Videos

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alxlab

alxlab

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Nice! Yeah tried messaging tomytronics on reddit to ask if the schematics were available. If not will need to redo the design in Kicad. The original Reply extender looks like it's either more that two layer design or they just attach all the ground pins to the ground plane on one side. I don't have a picture of the Reply card's on the back side though to know for sure. Taking a look at tomytronics' design it looks like some signals could be interfering with each other since they are closer to other signals rather than ground.

If it's not too much to ask, could you measure the width of the card? I got the height since I got a DOS card but not the width.

Edit: Oh yeah looks like the shield of the connectors are not connected to ground either on tomytronics' design.
 
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warmech

warmech

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alxlab said:
Nice! Yeah tried messaging tomytronics on reddit to ask if the schematics were available. If not will need to redo the design in Kicad. The original Reply extender looks like it's either more that two layer design or they just attach all the ground pins to the ground plane on one side. I don't have a picture of the Reply card's on the back side though to know for sure. Taking a look at tomytronics' design it looks like some signals could be interfering with each other since they are closer to other signals rather than ground.

If it's not too much to ask, could you measure the width of the card? I got the height since I got a DOS card but not the width.

Edit: Oh yeah looks like the shield of the connectors are not connected to ground either on tomytronics' design.
Click to expand...

For fun, I tossed one of the images into Illustrator and it looks roughly square. My DOS card measures 101.7mm in height; assuming the extension is the exact same height (and using some math to figure out the scaling factor in Illustrator), the width came out to about 101.1mm. That doesn't take image distortion into account or anything, but getting a ~0.5mm difference by virtue of (basically) eyeballing it is close enough that I'd guess it was square.
 
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alxlab

alxlab

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Yeah was planning to use a paint program if all else fails but I'd rather have measurement's with calipers if possible. Using callipers I got 101.5mm from my DOS card so 101.7mm is right in the ballpark :)
 
alxlab

alxlab

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I was able to get in contact with tomytronics and he offered to send over the design files since they aren't hosted anywhere. I asked him if he was ok if I hosted the files on github with a CC license. Will keep you peeps posted.
 
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warmech

warmech

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alxlab said:
I was able to get in contact with tomytronics and he offered to send over the design files since they are hosted anywhere. I asked him if he was ok if I hosted the files on githib with a CC license. Will keep you peeps posted.
Click to expand...

Any chance you heard back from tomytronics?
 
alxlab

alxlab

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Hi yes actually. I was planning to put it on github but didn't get a chance yet I guess I can post it here first. This is what tommytronics had to say about his design:

The ZIP files contains standard gerber files which should be usable with most program. SCH and BRD is for Eagle CAD

You are free to upload the original and modified files anywhere. The only impotent part to know is to keep the board’s width, the location of the connector on the DOS card side, and the 4 holes unchanged. The connector on the other side should be the same to use the same bracket off the Reply DOS cards or you could change it to break out game port and VGA port rather than to rely on hard to find cable.
Click to expand...

I will be posting it on github shortly. :)
 
warmech

warmech

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alxlab said:
Hi yes actually. I was planning to put it on github but didn't get a chance yet I guess I can post it here first. This is what tommytronics had to say about his design:



I will be posting it on github shortly. :)
Click to expand...

Ah, sweet! Glad to hear they were amicable to distributing their design! And modifying it to eliminate the cable is exactly what I intend to do, lol.

Let us know when it's in github - I'm chomping at the bit to take a look at it! :D
 
Drake

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alxlab said:
Hey @mg.man I never got around to making a modified version of the extender. @Drake made a modified version with an audio jack but I'm not exactly sure how that turned out.
Click to expand...
I have a bunch of the PCBs!
I just never got around to plugging it in lmao. The audio jacks I ordered were the incorrect footprint but at least I can test the video out signals
 
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