N64 region mod

[Tsurugi_Takuma]

Hi,

Hope this is ok to post here! Figured that there will be alot of us N64-nerds here and that this would be the perfect place to post this question.

So I'll be region nodding my PAL or NTSC-jap N64. Will be unsoldering both region chips. Will then solder them both to a new pcb. Will use a flip switch for power and then controlling which chip will be in use with relays. There seems to be 8-9 different lines to control with the relays, can't remember right now cause I'm not in front of my notes on my computer. The PCB will then be connected back to the 64!

So I know what I want to do and I kinda know how to solder, do you guys think this is doable project for a novice?

Best regards,
Nicklas

[marshallh]

I would probably use a CMOS switching chip instead of relays. You can get one for $2 that muxes up to 8 signals at once. But yes, to have both region support you would need a NTSC and PAL PIF installed and switchable.

Also, the clocking is different on PAL units than the rest. While all consoles use a 14.7mhz crystal for generating RDRAM timings, the second crystal depends on the region.

To have a truly region free N64 you'd need to have a cheap FPGA with a PLL to generate all possible frequencies, and you might as well use that FPGA to switch the PIFs as well. Would be a fun project.

[Tsurugi_Takuma]

Thanks for the reply

I'll go back to the drawing board and have look at an FPGA solution!

The difference in crystals has some impact on sound and game play etc, but the games should run anyway was my understanding.

Yeah the project should be fun and I'm probably gonna learn a bit about new areas in electronics while doing this. Only problem is that I work way to much, so not a lot of free time to do this :'(

Thanks again Marshall!

[Tsurugi_Takuma]

So while thinking about this I hade another thought. Is it possible to emulate the N64-hardware on an FPGA? Been following Brians endeavors of creating a HDMI-NES using FPGA. I know the N64 is way more complicated, but please indulge me and my stupid question

[Tsurugi_Takuma]

I would probably use a CMOS switching chip instead of relays. You can get one for $2 that muxes up to 8 signals at once. But yes, to have both region support you would need a NTSC and PAL PIF installed and switchable.

Also, the clocking is different on PAL units than the rest. While all consoles use a 14.7mhz crystal for generating RDRAM timings, the second crystal depends on the region.

To have a truly region free N64 you'd need to have a cheap FPGA with a PLL to generate all possible frequencies, and you might as well use that FPGA to switch the PIFs as well. Would be a fun project.

Is a Cyclone III overkill? Any suggestions of a good enough FPGA for a noob?

Would this one be good for the task:
http://www.ebay.com/itm/EP3C10-Cyclone- ... 3f2aa7ac1f

Or this one that is a bit smaller:
http://www.ebay.com/itm/Cyclone-IV-4-FP ... 35cd19320c

Thanks in advance

[meneerbeer]

I would probably use a CMOS switching chip instead of relays. You can get one for $2 that muxes up to 8 signals at once. But yes, to have both region support you would need a NTSC and PAL PIF installed and switchable.

Also, the clocking is different on PAL units than the rest. While all consoles use a 14.7mhz crystal for generating RDRAM timings, the second crystal depends on the region.

To have a truly region free N64 you'd need to have a cheap FPGA with a PLL to generate all possible frequencies, and you might as well use that FPGA to switch the PIFs as well. Would be a fun project.

Is a Cyclone III overkill? Any suggestions of a good enough FPGA for a noob?

Would this one be good for the task:
http://www.ebay.com/itm/EP3C10-Cyclone- ... 3f2aa7ac1f

Or this one that is a bit smaller:
http://www.ebay.com/itm/Cyclone-IV-4-FP ... 35cd19320c

Thanks in advance

Both would work. Both designs seem to be allright, they actually use decoupling caps for the FPGA. My board from China does not have a single one for the FPGA lol. I would go with the cheapest.

I could help you out with the code for this. I might want to do this mod as well. I mainly bought a flashcard to play NTSC ROMs, so it makes sense to change the clock signal.

[Tsurugi_Takuma]

Both would work. Both designs seem to be allright, they actually use decoupling caps for the FPGA. My board from China does not have a single one for the FPGA lol. I would go with the cheapest.

I could help you out with the code for this. I might want to do this mod as well. I mainly bought a flashcard to play NTSC ROMs, so it makes sense to change the clock signal.

Thank you will buy that one today. Excellent, I'm probably gonna need all the help I can get

Gonna buy another PAL-machine as well so I can tinker with this and still be able to play on my normal machine!

Edit: 2 FPGAs ordered! Hopefully I don't have to pay any import taxes and hopefully they will arrive whilst we're still in September

[Tsurugi_Takuma]

So I figure that I should be able to automate the switching between chips, if I remember correctly:
If leg 7 of the PAL-chip doesn't give any signal after X time, then reset and switch to NTSC. Might be totally of though...

FPGA:s shipped today from china. Waiting for a PAL unit to turn up at a reasonable price here in Sweden. Reading up a bit on the 64, mostly about the PIF-CIC's. So no real progress. Might pop out the NTSC-chip from the JAP 64 tomorrow, but then I can't play S&P until the mod is done :'(

[meneerbeer]

So I figure that I should be able to automate the switching between chips, if I remember correctly:
If leg 7 of the PAL-chip doesn't give any signal after X time, then reset and switch to NTSC. Might be totally of though...

Something like this should definitely be possible. Unfortunately I really do not know too much about the N64 hardware. Writing the VHDL for the FPGA to generate the clock frequency and select the right chip should not be a problem for me.

I am not sure about one thing. When you boot up the FPGA it first has to load its configuration. Maybe this process is too slow to perform when the N64 is turned on. I suppose you could connect the FPGA to the N64 power supply and have it always on. Another option is to make sure reset is activated when the N64 is powered on and the FPGA will deactivate after configuration.

Maybe there are better methods?

[marshallh]

pin 8 of the PIF is the PowerGood input, generated by a dedicated POR IC just above the PIF. It's basically a comparator, that goes high after the 3.3v rail is stable. You can cut this trace and drive it via some FPGA i/o. Such as when your PLLs are locked and ready to go.

You may play around with the PLL megafunction wizard to see what sorts of clocks you can derive from a 50mhz base clock (oscillator). It may be advantageous to use a different base clock to get a closer match. Your NTSC/PAL colorbursts are derived from them so they need to be pretty much bang on. Maybe even put a 14.318 and such for each region the FPGA board and just mux them with the FPGA.

You can also up the clock on the rambus interface slightly.