I'm just shooting in the dark here.. but if you got the main N64 IC's
# MIPS R4300i 64-bit RISC CPU running at 93.75MHz (1.5X bus multiplier)
# RCP (Reality CoProcessor), a custom vector processor developed by Nintendo and SGI, running at 62.5MHz
and then found blank ones of these chips ready to be programmed (I believe the RCP which is proprietary contains two main parts which aren't propritary, so could possibly get those parts and link them)
would it be at all possible to blind carbon copy the data from the chip off an N64 to the blank chip?
lucidPerspective wrote:I'm just shooting in the dark here.. but if you got the main N64 IC's
# MIPS R4300i 64-bit RISC CPU running at 93.75MHz (1.5X bus multiplier)
# RCP (Reality CoProcessor), a custom vector processor developed by Nintendo and SGI, running at 62.5MHz
and then found blank ones of these chips ready to be programmed (I believe the RCP which is proprietary contains two main parts which aren't propritary, so could possibly get those parts and link them)
would it be at all possible to blind carbon copy the data from the chip off an N64 to the blank chip?
Well those chips where never "blank" chips. They where manufactured that way ie not programmed. By blank chips I assume your talking about a FGPA (wiki it if you dont know). Since the N64 chips don't contain "data" you can't copy it.
Now if you spent a long time with an oscilloscope and tech documents and emulator code you could make a FPGA emulate the N64 chips.
The wood master
"I was under the impression Mac owners don't actually USE their machines, they just parade them around trying to evangelize the masses."
Cloning is possible for smaller dies, due to manufacturing processes it would be pretty hard to do with recent stuff.
Also the cost and equipment required--chip fabs spend millions, so I don't see this happening anytime soon.
The cpu would be extremely difficult but straightforward, it's an R4200 with a 32bit SysAD bus instead of 64bit. You could license the design from MIPS or write your own.
The RCP is damn near impossible to replicate unless you have detailed, low level docs on how it works. None of it is off the shelf, the RSP is close but still modified. At best you will have a somewhat-working clone. You will end up spending an infinite amount of time finding and fixing edge cases in your logic, kinda like what's happening to the LLE emulation efforts
Possible? With enough money and man hours. It will be some time before the device you'd use to implement it is cheaper than buying a N64.
Thanks for the response guys. I figured it'd be near impossible to do..
With the MIPS CPU. surely they're programmable on some level, as the factory that produces them will have to program them with the code they are given. So if I was to get a MIPS R4300i Processor from MIPS to design on/for (if they still have any) ..well surely there would be a reprogrammable version of this chip to prototype on. seems crazy to have to get a chip factory programmed each time you wanted to try your code out.
My hopes for the outcome of this is building something like those cheap SNES clones, but an N64. Although mass producing them would be illegal unless I wrote all the code myself (correct?) EDIT: as for the RCP, agreed that that will be near impossible to replicate. but emulation may be an option
N64 on a chip isn't gonna happen anytime soon, but we can dream.
The cpu could be done, with significant effort and time, but we only know what goes into the RCP and what comes out of it, no knowledge of how it arrives at the results it does.
Well, Oz0ne has gotten his hands dirty with the n64 if anyone's interested.
OzOnE wrote:With all the FPGA work, I now have a very good understanding of how the N64 and RCP work. If there are any specific questions on the chip signals etc, I should be able to help.
The N64 CPU and other processors aren't programmed and will never need to be. I can understand why you would think it would be necessary but every CPU has an instruction set built in (hard coded if you like). Any program you write will eventually get converted to machine code which is a series of instructions from this instruction set.
They don't need to be programmed to understand machine code because the machine code is adapted to directly manipulate the chip. This is a really clumsy way of explaining it and inaccurate by omission so I recommend you read deeper into CPUs, their architecture and how they work.
Wow, my brain must not have been working.. of course you don't program CPU's you program for them ..I'm blaming lack of sleep
But that sounds like it would be a good thing right, because we would then just have to dump the IC's that hold the N64's code and then hook them up to a MIPS R4300i processor. I say "just" very loosely, I know it's not that easy
I think you're confusing microcontrollers like PICs and AVRs that have small on-board flash ROMs to hold their programs. All desktop processors and the R4300i included have no such storage. They execute from the SysAD bus (which is a multiplexed address/data bus to save pins).
So there's nothing unique to the r4300i in the N64. In fact, there were a few business printers in the 90s that used the exact same CPU. They are 99% interchangeable.
There is actually MIPS code stored in the PIF, called IPL1 and 2. I think it's somewhere around 1700 bytes, that's what the CPU boots from. It is what loads the game's bootcode from the cartridge, and loads the CIC seed value before that. This is also dumped.
If you wanted to, you could wire up the cpu,some SDRAM, a small ROM and a FPGA and have yourself a basic R4300-based computer.
So the R4300i doesn't need to be changed. and we have the dumped code that the CPU needs to boot, and accept games. So the only thing that would need to be replicated would be the RCP correct?
is the RPC the same for all revisions of the N64, like for example. if someone was to manufacture a board containing a new R3400i, and all the other bits and pieces, and just got the RCP from faulty N64's (providing the RCP was still fine) would one be able to relatively easily create fully functional N64's?
My understanding was the the n64 cpu is slightly modified from the R4300i, much in the way that the 2A03 from the NES is a slightly modified 6502, same with the SNES and the 65816.
A few opcodes may have been changed or updated, features may have been added or removed.
But if you license a soft-core of the R4300i and modify it in that respect, I imagine you could replace the N64 cpu and still have it work.
