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Gimmick! famicom reproduction cart with 5b audio
http://forums.nesdev.com/viewtopic.php?f=28&t=9767
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Author:  Drakon [ Thu Jan 31, 2013 12:46 pm ]
Post subject:  Gimmick! famicom reproduction cart with 5b audio

This's a 15$ ebay gremlins 2 famicom pcb converted into a fully functional gimmick! cart with the extra audio due to me being lucky enough to get a cart with a sunsoft 5b chip in it.

The sound circuit which I found on a japanese website:

Image

The eproms are now directly soldered into the pcb and the precision sockets have been removed since everything is working. I built the audio circuit using the wrong parts (1.1k ohm instead of 1k ohm, 10 ufs instead of 1 ufs) which is why the audio circuit is just floating and not built into some nice protoboard while I wait for the right parts to show up in the mail. Probably the most annoying part of this mod was I had to desolder the suinsoft 5b chip using a heatgun to cut a trace underneath which was grounding one of the necessary audio pins. Wiring the prg eprom is annoying too because it's a 32 pin eprom in a 28 pin spot. One of the pins on the prg eprom (a17) needs to be connected to one of the sunsoft 5b pins which was left floating since the previous maskrom didn't use it). Here's the pcb in the current state:

Image

Image

And of course, a video of it in action (before I hard soldered in the eproms)

http://www.youtube.com/watch?v=hVJTyAoSzTM

A full wiring schematic will come later if I find enough time.

Author:  3gengames [ Thu Jan 31, 2013 1:01 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

Why do you STILL go crazy with the glue? Seriously, it looks like garbage and shows you can't make something structurally sound. Should have had all those parts on a piece of prototyping PCB on the outside with maybe blue to keep the PCB from moving. For the electronics, good. Nice. Thanks for doing it. Etc. But to show this off, make it look good, too.

Author:  Drakon [ Thu Jan 31, 2013 2:06 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

3gengames wrote:
Why do you STILL go crazy with the glue? Seriously, it looks like garbage and shows you can't make something structurally sound. Should have had all those parts on a piece of prototyping PCB on the outside with maybe blue to keep the PCB from moving. For the electronics, good. Nice. Thanks for doing it. Etc. But to show this off, make it look good, too.

It'll be inside a case so you won't have to stare at it. If you don't like it, then go post elsewhere, all you ever do is bitch.

Author:  3gengames [ Thu Jan 31, 2013 2:09 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

If you drop it, it'll still move all those outside wires, eventually two will short! Doesn't matter if it's in a case, especailly if it breaks.

Author:  Drakon [ Thu Jan 31, 2013 2:53 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

3gengames wrote:
If you drop it, it'll still move all those outside wires, eventually two will short! Doesn't matter if it's in a case, especailly if it breaks.


The audio wiring is temporary I already clearly stated that. I'm not using the right parts for the audio circuit so I'm leaving it like this until the right parts arrive in the mail.

Author:  rainwarrior [ Thu Jan 31, 2013 3:08 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

Hey, you did it! Congratulations!

Author:  Drakon [ Thu Jan 31, 2013 4:29 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

rainwarrior wrote:
Hey, you did it! Congratulations!

Thankyou! Always nice to know there's some people who know how to be supportive.

Author:  lidnariq [ Thu Jan 31, 2013 4:51 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

Out of curiosity, why are you using strands of stranded ribbon cable (HDD?) rather than solid 30ga kynar or magnet wire or similar?

Author:  keropi [ Thu Jan 31, 2013 5:12 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

lidnariq wrote:
Out of curiosity, why are you using strands of stranded ribbon cable (HDD?) rather than solid 30ga kynar or magnet wire or similar?


I don't see how in this case the hdd cable or kynar would make any difference...

Author:  80sFREAK [ Thu Jan 31, 2013 5:13 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

3gengames wrote:
Why do you STILL go crazy with the glue? Seriously, it looks like garbage and shows you can't make something structurally sound. Should have had all those parts on a piece of prototyping PCB on the outside with maybe blue to keep the PCB from moving. For the electronics, good. Nice. Thanks for doing it. Etc. But to show this off, make it look good, too.

F***ing brilliant comment! Try to imagine, how it will looks like with AY chip :shock:

Author:  MottZilla [ Thu Jan 31, 2013 7:03 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

I would agree, I hope you can make it look nicer when it's all said and done. It really does look like a WIP with the long wires and glue. But functional certainly counts for alot. Post another picture when you're done. Also, I saw your video and thumbs up for using a real TV to play NES/Famicom and not a crappy Digital TV.

Author:  proveaux [ Thu Jan 31, 2013 8:10 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

Congrats on getting it to work!

Author:  infiniteneslives [ Thu Jan 31, 2013 8:45 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

lidnariq wrote:
Out of curiosity, why are you using strands of stranded ribbon cable (HDD?) rather than solid 30ga kynar or magnet wire or similar?


I think it's a matter of preference really. I prefer to use the HDD style wires for most of my projects. I used to use solid core wire, but my major issue with it is there is little to no stress relief on the solder joint. If the wire gets pushed or pulled much it'll break free. Although when the whole thing is coated with glue, it's of less concern. :) BTW, is all the glue for stress relief?

Author:  Drakon [ Thu Jan 31, 2013 9:35 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

God, for the third time now yes this is still a work in progress. I'm waiting on parts to build the proper audio circuit that's why it's like this right now.

proveaux wrote:
Congrats on getting it to work!

Thankyou.

infiniteneslives wrote:
lidnariq wrote:
I think it's a matter of preference really. I prefer to use the HDD style wires for most of my projects. I used to use solid core wire, but my major issue with it is there is little to no stress relief on the solder joint. If the wire gets pushed or pulled much it'll break free. Although when the whole thing is coated with glue, it's of less concern. :) BTW, is all the glue for stress relief?

Yeah I like a little stress relief on my wires. And yes the glue is for stress relief. It may be a bit excessive but it's not harming anything.

Author:  blargg [ Thu Jan 31, 2013 9:44 pm ]
Post subject:  Re: Gimmick! famicom reproduction cart with 5b audio

Your stress-relieving glue sure is causing lots of stress in this forum! :)

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