Hacking up an original famicom

psychotic_mechanic · Post by **psychotic_mechanic** » Sun Jun 04, 2006 4:12 am

I had a couple famicoms here that weren't working correctly, so I started pulling them apart looking towards a portable project.

The boards really lend them selves to portabilizing, it's in 2 parts with the RF doodads and 7805 on one board and the CPU chips on another. The main board is about 4x6 inches and has no lockout chip to worry about. I already worked the pinouts for the board and got it working on my small test TV with jumper wires from pos,neg ,audio,video and AV ground.

Next step is a cart slot relocation/conversion to 72 pin.

Another weird famicom factoid: Dragon Quest 1 and 2 are password games, no batteries inside.

psychotic_mechanic · Post by **psychotic_mechanic** » Mon Jun 05, 2006 7:48 pm

I know what capacitors do, and how they do it, but I have a question concerning the capacitors on the NES/famicom board. Are they really necessary? They're on a seperate board from the rest of my famicom and I've already bypassed them running the famicom to AV out. I wonder if I can leave them off altogether. I'll check the traces when I get home and try pwering the system off of just a bare 7805.

Post by **CronoTriggerfan** » Mon Jun 05, 2006 8:12 pm

If knowledge serves, you SHOULD do fine with that part gone; I think it goes to the RF box originally. Just test it out without the capacitor board, then replace it if it doesn't.

CTFan

psychotic_mechanic · Post by **psychotic_mechanic** » Tue Jun 06, 2006 4:30 am

It runs without the capacitors, but video quality has really suffered. (looks like the "horizontal hold" is messed up an an old TV) I'll try pulling out a capacitor from one of these spare part VCR's I've picked up from the curb and running it inline on the main power to see if that helps.

Measured the power draw from the famicom while running Dragon Quest2, it's right at 320 mA. If my screen pulls around around 500 mA, a 3200 mA battery would give me about 4 hours.

I've decided I don't have enough jumper wires or desk space...

arfink · Post by **arfink** » Sun Jun 11, 2006 2:15 pm

The origional famicom idea sounds very good, can you send some pics of your guts that youve been building? I was also thinking that the second edition Famicom would be pretty good to hack up.

psychotic_mechanic · Post by **psychotic_mechanic** » Sun Jun 11, 2006 8:34 pm

I'll clean up my worktable and snap some pictures. I didn't get a chance to work on it this weekend, I was busy cleaning out the closets (I found a receipt from Electronics Boutique from 1995 for $46 and was wondering what game I had bought. I'm thinking it was a sega CD, could have been Lunar) and throwing out a lot of stuff I had been keeping "just in case".

There is something definitely wrong with the video though, I hooked up the original RF box and the video still came out screwy, even taking the video out from differet places on the board.

psychotic_mechanic · Post by **psychotic_mechanic** » Fri Jun 16, 2006 9:26 pm

Figured out my problem. If you accidentally apply +5V to the "common ground" of the AV circuits, the sound still plays OK, but the video gets screwy. Sometimes it helps to take a break and them come back "fresh" to look at your problem again.

I'll have some pics up soon, but it doesn't look like much yet.

I'm still trying to decide if I want (A) both a 72 and 60 pin connectors (B) ninja-1337 connector that expands to accomodate 72 and 60 pin carts or (C) just use a 60 pin to 72 pin connector to play fami-carts on my portable becacause they should be around the same size as a NES cart.

I need to pick up a desoldering iron, my desoldering braid works for small components, but just isn't cutting it for the big stuff.

EDIT: here's the project so far: picbucket

I still need to do a lot of work. NES cart included for size comparison.

jeroen · Post by **jeroen** » Sat Jun 17, 2006 5:54 am

I can't believe how small that is. I want one. Even though i'm in pal and it is ntsc that would be so cool to have. Super small nes portable.

psychotic_mechanic · Post by **psychotic_mechanic** » Sat Jun 17, 2006 6:11 am

The cool thing is that it will be "official" hardware. I'm hoping that it will play all the NES games accurately, I should probably test out Castlevania 3 one of these days.

I want to take the controller port out in one piece so I can make a famicom to NES controller adaptor.

arfink · Post by **arfink** » Sat Jun 17, 2006 4:42 pm

NICE!That is very small! Is that the first revision famicom hardware, or the second revision? Also, do you know if Castelvania 3 will play on a NOAC? Or is it just the japanese version of CV3 that has problems? I have played the japanese version of CV3 and the sound is... wow... amazing. It would be too bad if my NOAC can't play that game. It should be in the mail to me now.

edit: BTW, how much would one of those mobos cost me from you? I might like to have one for... some evil project or other

I have heard stories of people being consistently dissapointed in the noac for certain types of games.

psychotic_mechanic · Post by **psychotic_mechanic** » Sat Jun 17, 2006 5:07 pm

I don't know how to tell the difference between a version 1 and 2, but I do have a couple around here that I've noticed some differences on.

I hadn't really thought about selling the mobos, I usually clean up th systems and sell them on ebay. The ones I'm hacking now had problems (bad 7805, etc) that made them good candidates for this. I may stick my yobo inside the famicom case just for the fun of it.

I'll keep an eye out later today for cheap famicoms (I've picked them up for as little as $2 or as much as $15 in junk shops, which is fair price for an NES in the states depending on condition).