Nekochan Net

I would like to ask if it is a good idea and if there is enough interest to make a separate subforum about emulators.

This subforum should cover running emulators on SGI machines like MAME/MESS, Vice(C64), Stella(VCS2600), UAE(Amiga).
Also development progress of emulators which can emulate MIPS processors and SGI machines like GXEmul, VMIPS, Simos, MESS and Miep should be discussed.

My motivation for this request:
- Recently Axatax made great progress in mame and openGL development, making it a very viable way of playing games on IRIX machines.
- MESS versions 0145 till 0147 has workable Indy support and while not everything is implemented, it's getting close. I'd like to generate momentum to finish this driver, since there is no true emulator around for any of the SGI machines. The Indy is hardwarewise sufficiently documented to make the emulation a success.

Yay's and Nay's are welcome...

Sounds like a good idea.. I always wanted to get to grips with the big blue mainframe emulator I had years ago..

Sounds good! Emulators are nifty tools if we can get some working well, as it instantly opens up a new catalogue of usable software/games, so I'm in favour of it! It'll help to keep the bits together anyway.

I have no objection, I just wonder about the level of interest.

ClassicHasClass wrote: I have no objection, I just wonder about the level of interest.

Which is exactly the reason i'm asking this. I don't know. But i rather have a separate subforum dealing with this subject matter than to either post in SGI:Development about MAME on IRIX and then going to Miscellaneous:Other for SGI emulators like MESS

I do have contact with MAME developer Mooglyguy which is now collecting SGI roms to be put into MESS staging by adding skeleton drivers, so my guess is that more roms and skeleton drivers will follow in the coming months. Therefore i have a hunch we will attract other people interested in SGI emulation.

dexter1 wrote: But i rather have a separate subforum dealing with this subject matter than to either post in SGI:Development about MAME on IRIX and then going to Miscellaneous:Other for SGI emulators like MESS

I think it makes a lot of sense to set up a subforum for this.

Even if traffic is light compared to some of the major subfora, the topic comes up often enough that it is noticeable, and, as you suggest, it really is a different body of knowledge than what typically goes SGI:Development and Miscellaneous:Other.

don't expect to emulate Octane, Fuel, Tezro, etc
the best we can do is within: { Indy/R5K, O2/R5K }

ivelegacy wrote: don't expect to emulate Octane, Fuel, Tezro, etc
the best we can do is within: { Indy/R5K, O2/R5K }

That is not entirely true. GXEmul claims partial O2-R10K emulation, but currently without Crime chipset and AIC7880 SCSI support, since there are no specs.
With Indy+newport emulation also comes R4K Indigo2 emulation with EISA support and XL24 framebuffer. GR3/GU1 cards and Impact subsystem are unsupported, as are R10K CPU's on Indigo2 systems.

Attempts of emulating Octanes, Fuels and other IP35 derivatives is IMO not going to be very fruitful in the foreseeable future since the CPU emulation needs some sort of Binary Translation to attain sufficient processing speed. Dynamic Recompilation will probably not be able to keep up.

dexter1 wrote:

ivelegacy wrote: don't expect to emulate Octane, Fuel, Tezro, etc
the best we can do is within: { Indy/R5K, O2/R5K }

That is not entirely true. GXEmul claims partial O2-R10K emulation, but currently without Crime chipset and AIC7880 SCSI support, since there are no specs.
With Indy+newport emulation also comes R4K Indigo2 emulation with EISA support and XL24 framebuffer. GR3/GU1 cards and Impact subsystem are unsupported, as are R10K CPU's on Indigo2 systems.

Attempts of emulating Octanes, Fuels and other IP35 derivatives is IMO not going to be very fruitful in the foreseeable future since the CPU emulation needs some sort of Binary Translation to attain sufficient processing speed. Dynamic Recompilation will probably not be able to keep up.

This seems like nonsense to me. Your slowest possible Octane configuration is a 195MHz single-CPU system. That's slower than a PlayStation 2. And even if you don't have full-speed emulation, an emulator can still be useful, depending on what you want it for.

GXEmul seems to be dead as of nearly a year and a half ago now, in the middle of a major restructuring?

dexter1 wrote: That is not entirely true. GXEmul claims partial O2-R10K emulation

who cares, chap ? do you know how much effort is required in order to support R10K decently ?
and it's not reasonable at all, it's absolutely not the point(1), unless you can allocate a lot of human resources

(1) the real problem is: in first place all the ASIC around the CPU, and in second place we need a way to speed up the whole
which implies optimization tricks, dynamical translation voodoo, etc etc etc


edit:
I also wonder if we'd better
- use a real MIPS4 machine (OCTEON MIPS64 Processors by Cavium?)
- do a bit of voodoo in order to virtualize Irix over a linux kernel
- and try to emulate the IP22/IP32's ASIC by software

I was referring to the list of Ivelegacy which in his spirit mentioning the SGI workstations capable of running R14K/R16K cpu's. I did not intend to mention emulation of single CPU Octanes, that was simply not my point.

Emulating an Octane includes emulating the graphics subsystem, sound and IO. Since in the current state there is no documentation for either the Impact or VPro graphics subsystem (let alone the heart ASIC), attempts will be limited to console/terminal state for now.

ivelegacy wrote: who cares, chap ? do you know how much effort is required in order to support R10K decently ?

Well, chap, i do know, and i haven't claimed anything in terms of usability of the emulation. I clearly stated "not entirely", so please mind the subleties and nuances, they are there for a reason.

I know nothing about emulation and would have zero interest towards the development of such a project. However, I would be very happy if there was some sort of virtual SGI that I could use and ran Irix, even an older version like 6.2. Even if it ran at Indy R4000PC speeds We can always throw more modern horsepower at it. If target performance around an r4400sc indy with xz graphics on an i5 were possible it would be very neat and maybe even useful. Since I guess the host would be linux or osx I can see why this discussion is not suitable for irix development forums

This sounds very different from running e.g. MAME on an SGI (the other way around). Why is that discussion not suitable for the irix development forums?

guardian452 wrote: ... I would be very happy if there was some sort of virtual SGI that I could use and ran Irix, even an older version like 6.2.

Exactly, that would be awesome: to test software or try out different emulated hardware, but it would also act as a sort of preservation of the technology, since our SGI machines have a finite lifespan. i became weary of reviving old SGI's after one of my Indy's blew a capacitor last september, simply by turning it on.

Even if it ran at Indy R4000PC speeds We can always throw more modern horsepower at it. If target performance around an r4400sc indy with xz graphics on an i5 were possible it would be very neat and maybe even useful.

I'll come back on indy emulation speeds and problems/solutions later in a different post, but your target platform choice is pretty close to some emulators. For now, let me suffice in stating that newport gfx (XL8/24) in combination with an R4600PC@133Mhz would very likely be the first configuration to achieve proper emulation. And reports from MESS developers have stated that by removing debug statements they could achieve full speed on R4600PC CPU emulation.

Since I guess the host would be linux or osx I can see why this discussion is not suitable for irix development forums

Indeed, hence my question for creating a subforum. I'll poke Neko if he thinks it's a good idea.

This sounds very different from running e.g. MAME on an SGI (the other way around). Why is that discussion not suitable for the irix development forums?

Oh it most certainly is suitable. I was just wondering if MAME users and developers are satisfied with the current threads on that forum: If axatax needs help or if there are many requests for adding machines to a particular MAME version, which is happening now, we might need to think about a separate section for them.

dexter1 wrote:

guardian452 wrote: Since I guess the host would be linux or osx I can see why this discussion is not suitable for irix development forums

Indeed, hence my question for creating a subforum.

Exactly! I fully agree.