- Joined
- Jun 6, 2020
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- Portables
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I've been doing Wii portables for quite some time now, and I've been starting to feel the monotony of the builds crushing my soul. I've been wanting to branch out into other consoles for quite some time now, but so many other projects have taken priority.... until now! This first post spans over the course of a couple days, leading up to a few hours ago...
DAY ONE
In between commissions, I've started to go down the N64 rabbit hole - reading through the advanced trimming guide and getting to understand all of the relocations and critical points on the N64. I've read through many worklogs (especially @SparkleBear's First N64p thread) and got super hyped up to try something myself. I bought a bunch of N64s with expansion paks, and one night I just went for it and did an advanced trim:
DAY TWO
In my portable-to-be, I wanted to swap the RAM for two 4mb chips as many have done. I also wanted to try my hand at the "Akira method" for RAM termination. In my craving to have a trimmed N64 in my hands, I failed to use my head and do these relocations before trimming. By not validating either of these relocations prior to trimming, I was potentially setting myself up for a big headache down the road if something didn't work correctly.
All that being said and understood, I got to work yesterday to start the relocation process. I have to start by thanking @YveltalGriffin for answering my many questions throughout the Akira method process. Equipped with a good understanding of what I need to do, I pulled the 2mb RAM chips from the board and cut out the RAM termination pins to expose the bare FR4:
From there, I just followed the pictures Akira posted, and after about an hour and a half or so later, it was done!
Yveltal was right: it's really not as scary as it's made out to be. After checking all my connections with my DMM to make sure all the pins had the right resistances to ground and none of them were shorted together, I added the 4mb RAM chips from two expansion paks:
DAY THREE (current day)
I did a lot of studying for the PIF relocation and used my DMM to trace a lot of the relocation points and where else these signals ran around the board. Luckily, with the trim that I did, I preserved the majority of the left set of pins on the original PIF footprint, making for a cleaner relocation. I didn't want to to wire anything directly back to the cartridge slot, so I traced pins 7 and 24 (23) back and found a nice place to scratch the traces and solder the wires there. The only long wires I had to run were for pins 7 and 25 going to CPU. Looks ugly IMO, but it will have to do! I also jumped all the 3v3 points on the back of the board with a few short wires so, from the front of the board, it looks pretty barren.
Checking for continuity in all the right spots, I was pretty confident that this relocation would work. Trucking ahead, it was time to relocate the cartridge slot. After snipping and tinning 46 wires, I wired everything from the N64 to the cartridge slot:
Stuck a cart in, gave it power and....... nothing! I probed around looking for issues and then it dawned on me: I wired the cart slot the wrong way, swapping the top and bottom row. It's crazy how desoldering all those wires was so much faster than soldering them! Anyway, I redid all the wiring with the correct orientation, but it still didn't work. When doing the PIF relocation and tracing back points, I found that the relocation point(s) for pin 8 did not have a direct connection with the original pin 8 pad. Rather, there was a 50k resistor between the two. I kept that in the back of my mind, and I figured if relocating back to the original pad didn't work, I could jump 2 points and bypass the resistor. If anyone knows why this is the case, drop some info bombs here! After jumping those points, bam!
Just for tickles, I also hooked it up to everyone's favorite 5" 4:3 screen:
FUTURE PLANS
Let's hope I can stay on this project longer than the other ones I've made worklogs for...
DAY ONE
In between commissions, I've started to go down the N64 rabbit hole - reading through the advanced trimming guide and getting to understand all of the relocations and critical points on the N64. I've read through many worklogs (especially @SparkleBear's First N64p thread) and got super hyped up to try something myself. I bought a bunch of N64s with expansion paks, and one night I just went for it and did an advanced trim:
DAY TWO
In my portable-to-be, I wanted to swap the RAM for two 4mb chips as many have done. I also wanted to try my hand at the "Akira method" for RAM termination. In my craving to have a trimmed N64 in my hands, I failed to use my head and do these relocations before trimming. By not validating either of these relocations prior to trimming, I was potentially setting myself up for a big headache down the road if something didn't work correctly.
All that being said and understood, I got to work yesterday to start the relocation process. I have to start by thanking @YveltalGriffin for answering my many questions throughout the Akira method process. Equipped with a good understanding of what I need to do, I pulled the 2mb RAM chips from the board and cut out the RAM termination pins to expose the bare FR4:
From there, I just followed the pictures Akira posted, and after about an hour and a half or so later, it was done!
Yveltal was right: it's really not as scary as it's made out to be. After checking all my connections with my DMM to make sure all the pins had the right resistances to ground and none of them were shorted together, I added the 4mb RAM chips from two expansion paks:
DAY THREE (current day)
I did a lot of studying for the PIF relocation and used my DMM to trace a lot of the relocation points and where else these signals ran around the board. Luckily, with the trim that I did, I preserved the majority of the left set of pins on the original PIF footprint, making for a cleaner relocation. I didn't want to to wire anything directly back to the cartridge slot, so I traced pins 7 and 24 (23) back and found a nice place to scratch the traces and solder the wires there. The only long wires I had to run were for pins 7 and 25 going to CPU. Looks ugly IMO, but it will have to do! I also jumped all the 3v3 points on the back of the board with a few short wires so, from the front of the board, it looks pretty barren.
Checking for continuity in all the right spots, I was pretty confident that this relocation would work. Trucking ahead, it was time to relocate the cartridge slot. After snipping and tinning 46 wires, I wired everything from the N64 to the cartridge slot:
Stuck a cart in, gave it power and....... nothing! I probed around looking for issues and then it dawned on me: I wired the cart slot the wrong way, swapping the top and bottom row. It's crazy how desoldering all those wires was so much faster than soldering them! Anyway, I redid all the wiring with the correct orientation, but it still didn't work. When doing the PIF relocation and tracing back points, I found that the relocation point(s) for pin 8 did not have a direct connection with the original pin 8 pad. Rather, there was a 50k resistor between the two. I kept that in the back of my mind, and I figured if relocating back to the original pad didn't work, I could jump 2 points and bypass the resistor. If anyone knows why this is the case, drop some info bombs here! After jumping those points, bam!
Just for tickles, I also hooked it up to everyone's favorite 5" 4:3 screen:
FUTURE PLANS
- Power Management TBD
- 64-Amp for audio
- Custom controller board with uC for joystick conversion (with the help of @Gman)
- Chop off the cart slot and make use of Yveltal's RCP-Cart Slot flex PCB
- This will be my first project designing my own case, so that's going to be fun
- Not sure if this will have 2 or 4 18650s; I want to get more progress done on the fundamentals before I go into cramming it in a case.
