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Personal 4 port cartridge expansion project


Sinphaltimus

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Well, it's all wiored up and with the exception of the following 3 issues, this project might have been done today.

I found 3 issues. I'm afraid they might be a faulty switches, port 2 and port 3 issues might also be broken solder points that I'll have to trace out to locate where the open is.

With port 1 selected, I'm getting connectivity on port 2 pin 21. <suspect bad switch pole - I can change this fairly easily.

With port 2 selected I'm not getting any connectivity on port 2 pin 34. <suspect bad switch pole or broken solder point.

With port 3 selected I'm not getting any connectivity on port 3 pin 21. <suspect bad switch pole or broken solder point.

So I still have some work cut out for me. But not today, I've been at this most of the day. I'll have to pick it up again tomorrow morning.

Edited by Sinphaltimus
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Sinphaltimus,

Has anyone yet told you about "the TI demonstration curse"? It's TRUE!

No. But I think I have it.

 

 

Oh and this:

 

Project Album

 

EDIT:

OK, so man handling this thing loosened up a few connections. So I tightened them up. Also, one of my mounted jumpers came loose which would explain the short of GROM2. So I tightened everything up, and tested my switches, they work as far as I can tell. BUT, no matter what port is selected, I can load a cart from any one of the ports. On other words, if I have port 1 selected, the cart loads up (PARSEC) just fine on port 1, 2, 3 and 4. It really is behaving as though it is wired straight through without the switches. Each GROM operates fine independant of the switch selection.

And yet, when I trace continuity from console port through grom port, everything checks out.

 

I get no connections across pins 21, 31 and 34 on GROM ports that are not selected by a switch. I honestly do not know what I did wrong. It makes zero sense to me.

 

So bizarre. I'm actually contemplating quickly building a second one without the connectors and just soldering wires directly to pins and such. If I work on it every night, I might get it done before FestWest. But I have to jump between trouble shooting this more and more and more and more until the solution presents itself and actually starting from scratch with a much more manageable design.

 

I guess I'll sleep on it first.

Edited by Sinphaltimus
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No. But I think I have it.

 

 

Oh and this:

 

Project Album

 

EDIT:

OK, so man handling this thing loosened up a few connections. So I tightened them up. Also, one of my mounted jumpers came loose which would explain the short of GROM2. So I tightened everything up, and tested my switches, they work as far as I can tell. BUT, no matter what port is selected, I can load a cart from any one of the ports. On other words, if I have port 1 selected, the cart loads up (PARSEC) just fine on port 1, 2, 3 and 4. It really is behaving as though it is wired straight through without the switches. Each GROM operates fine independant of the switch selection.

And yet, when I trace continuity from console port through grom port, everything checks out.

 

I get no connections across pins 21, 31 and 34 on GROM ports that are not selected by a switch. I honestly do not know what I did wrong. It makes zero sense to me.

 

So bizarre. I'm actually contemplating quickly building a second one without the connectors and just soldering wires directly to pins and such. If I work on it every night, I might get it done before FestWest. But I have to jump between trouble shooting this more and more and more and more until the solution presents itself and actually starting from scratch with a much more manageable design.

 

I guess I'll sleep on it first.

 

I know I tore my 2 port down 4 or 5 times working on troubleshooting.

 

I feel your pain but yours is twice as much as mine!

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I know I tore my 2 port down 4 or 5 times working on troubleshooting.

 

I feel your pain but yours is twice as much as mine!

 

 

LOL! That's exactly what I decided to do. I unwired everything, reinforced, moved a couple of things and have started rewiring everything again, but differently this time. Should make it look neater and easier to troubleshoot if need be when I'm done.

 

I got pins 1-21, 31, 34 done. Resistor and switches done. Then I ran out of gas. Gonna turn in now and pick it up again bright and early to finish the last group of connections then we'll see where I stand.

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OK, stumped. I hit up the 2 folks who have been helping along this far and hopefully one of them finds the issue in my drawings otherwise, I am at a complete loss. Totally stumped.

I posted the update here to get more eyes on it in case we're overlooking something.

Switches are working as expected but the entire thing is behaving as if it is wired straight through (all switches engaged at once).

Example, I put one cart (parsec) in to port 1 and it works with the console no matter what switch I have selected.
Same results if parsec is in ports 2-4.

Below is the final schematic showing all wires.

And then a very crude drawing of the actual relevant wires and how I physically split and connected them. All remaining wires are straight from console port to GROM port (not illustrated in crude drawing).

 

post-47352-0-14204000-1491748385_thumb.png

 

post-47352-0-65693900-1491748387_thumb.png

 

 

UPDATE: As per Shift838's suggestion, I checked voltages at the GROM ports and from the edge connector to the GROM the voltage drops from 5v to 2.5 essentially. And no voltage on G4. This is with Port 1 selected as active.

So somethings not right, I'm thinking my materials. Not sure If I'll have time to build another before FW17, I may start it anyway. I'll bring this concoction with me to FW anyway. It's easy to tear down and build back (takes about an hour). Maybe I'll sit at a back table and troubleshoot it there with someone. Dunno how feasible that would be.


UPDATE 2:

I'm beginning to doubt these switches. A couple of times when testing they appear to not function as expected. So pushing one in then popping it out again by selecting another switch sometimes requires me to do it twice. I guess I didn't know what to expect using these very old radio shack a/v switch boxes. so I ordered some switches that will at least give be stability there. I'll connect them when they arrive Thursday. At least then I will know if my hunch was correct and get this project to work.

Edited by Sinphaltimus
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Despite the fact that others have have success with this build....

I can't get it to work. Pretty much the same results. It's behaving as if the wires are straight through with no switches attached. So I can use anyone port independent of the others as long as there are no other carts installed. That's about it. I'm at a complete loss. the switches are new, they pass continuity testing and all my wires and resistors are in place as they should be. I guess i can bring it to FW to show off how not to make a switchbox.

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Despite the fact that others have have success with this build....

 

I can't get it to work. Pretty much the same results. It's behaving as if the wires are straight through with no switches attached. So I can use anyone port independent of the others as long as there are no other carts installed. That's about it. I'm at a complete loss. the switches are new, they pass continuity testing and all my wires and resistors are in place as they should be. I guess i can bring it to FW to show off how not to make a switchbox.

Hang in there buddy! We need you back writing games anyway. Software is where it's at!

 

 

Sent from my iPhone using Tapatalk

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Yeah, I've already rewritten Zombi in my head several times these past few weeks. I'm going to change the scope of the game to over-come the performance hits. One thing that's going to be a big change is spawning in zombies when one is killed so I can give the impression of a lot of zombies on a level without have to load them all and track them all at once. The only purpose for me to do this HW project was That I really do need a 4-port cartridge switcher for my console. One that works with all the popular cart formats.

Edited by Sinphaltimus
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Despite the fact that others have have success with this build....

 

I can't get it to work. Pretty much the same results. It's behaving as if the wires are straight through with no switches attached. So I can use anyone port independent of the others as long as there are no other carts installed. That's about it. I'm at a complete loss. the switches are new, they pass continuity testing and all my wires and resistors are in place as they should be. I guess i can bring it to FW to show off how not to make a switchbox.

 

Maybe another pair of eyes will spot something at FW.

 

-M@

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Well regardless of the consensus at FW, I'm going to build a different unit when I get back. I'm going to need help getting a board design I can send in for manufacture once I have a usable schematic. Hopefully I can get a volunteer to create the file I need for OSH park. Or at least get a lot of help learning to do it myself.

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So am I to understand Zombie development is undead?

 

Ha. Yeah I suppose. It was never dead. Just got real busy. I'm starting my own business and working extra so less time off and less time for hobbies. I need this 4 port cart switcher so as soon as I have it working it's back to Zombi.

Sent from my iPhone using Tapatalk

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  • 10 months later...

I'm resurrecting this because too many recent things are pushing me back in this direction.

First, the Navarone from Vorticon. I now have that and am planning on studying it closely.
Next, Shift838 publishing his 2 port version. I lack the skill and knowledge to create my own PCB design for this project and that is what really holds this up. I can't deal with the prototype and all the wires and connections I made while working on this.

Finally, Yesterday's news with a navarone modification article in it.

I think that article brought me back to a moment of confusion that I don't think cleared itself .

 

I need to know what the pinouts are if you are physically looking into the cart port of your console.

At first i used the image on the left (below) but was told by someone that is how they are on the mainboard but with the 90 degree adaptor in there ofr cart placement, the pins flip vertically. Then I was told by someone else much later that was incorrect and the diagram shows the actual pins as they appear on the 90 degree adaptor, then reading this article it talks about pin 1 being on the right side but I'm unclear if they are talking about the grom port or looking at the card connector from the grom port's perspective.

I just need to know a definitive answer. If I flip the little door open and look inside my console's cartridge port with a flashlight, what pin is the upper most left pin? This is probably why this project stalled out, I'm not getting the pin assignments correct.

post-47352-0-52384800-1519918442_thumb.png

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I'm resurrecting this because too many recent things are pushing me back in this direction.

 

First, the Navarone from Vorticon. I now have that and am planning on studying it closely.

Next, Shift838 publishing his 2 port version. I lack the skill and knowledge to create my own PCB design for this project and that is what really holds this up. I can't deal with the prototype and all the wires and connections I made while working on this.

 

Finally, Yesterday's news with a navarone modification article in it.

 

I think that article brought me back to a moment of confusion that I don't think cleared itself .

 

I need to know what the pinouts are if you are physically looking into the cart port of your console.

 

At first i used the image on the left (below) but was told by someone that is how they are on the mainboard but with the 90 degree adaptor in there ofr cart placement, the pins flip vertically. Then I was told by someone else much later that was incorrect and the diagram shows the actual pins as they appear on the 90 degree adaptor, then reading this article it talks about pin 1 being on the right side but I'm unclear if they are talking about the grom port or looking at the card connector from the grom port's perspective.

 

I just need to know a definitive answer. If I flip the little door open and look inside my console's cartridge port with a flashlight, what pin is the upper most left pin? This is probably why this project stalled out, I'm not getting the pin assignments correct.

 

attachicon.gifUntitled.png

 

However the right-angle connector handles the pinouts, your left diagram is correct—with pin 1 on the bottom left. That is my conclusion with a visual trace of my Widgit [sic], which has the reset pin in that position. I can only guess from this that the outlined verbiage on the right refers to looking directly toward the lands of the cartridge edge as though your eyes were the console socket extender. (clear as mud, right?!)

 

...lee

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  • 1 month later...

I'm resurrecting this because too many recent things are pushing me back in this direction.

 

First, the Navarone from Vorticon. I now have that and am planning on studying it closely.

Next, Shift838 publishing his 2 port version. I lack the skill and knowledge to create my own PCB design for this project and that is what really holds this up. I can't deal with the prototype and all the wires and connections I made while working on this.

 

Finally, Yesterday's news with a navarone modification article in it.

 

I think that article brought me back to a moment of confusion that I don't think cleared itself .

 

I need to know what the pinouts are if you are physically looking into the cart port of your console.

 

At first i used the image on the left (below) but was told by someone that is how they are on the mainboard but with the 90 degree adaptor in there ofr cart placement, the pins flip vertically. Then I was told by someone else much later that was incorrect and the diagram shows the actual pins as they appear on the 90 degree adaptor, then reading this article it talks about pin 1 being on the right side but I'm unclear if they are talking about the grom port or looking at the card connector from the grom port's perspective.

 

I just need to know a definitive answer. If I flip the little door open and look inside my console's cartridge port with a flashlight, what pin is the upper most left pin? This is probably why this project stalled out, I'm not getting the pin assignments correct.

 

attachicon.gifUntitled.png

 

 

Another check you have is the GramKracker schematic you're reproducing. It's has an "as your looking into the port" set of pin numbers.

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Another check you have is the GramKracker schematic you're reproducing. It's has an "as your looking into the port" set of pin numbers.

 

 

Oh, I've been looking at that a lot lately. :) It sure crossed my mind more than once (this topic here) - I'm just no good with building a jumper wired prototype. I need to learn how to make a 2 layer PCB and just solder in the switched, resistors, and GROM ports.

 

Someday.

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