http://www.emulator-zone.com/doc.php/genesis/ I've been watching this for a while seeing if anyone was going to correct it... no corrections. There's no way there's a 14dB S/N ratio. That number doesn't make any sense. I had explained it to them, but I got no reply. While I was looking through it again, I noticed the the number of planes it lists... isn't there TWO sprite planes and FOUR scrolling planes? (correct me if I'm wrong.) Also, they got specific about the Motorolla speed, but rounded the Z80 up to 4, which to me is quite a big difference. And finally, isn't there a 4MB ROM area rather than 1MB? If I'm technically wrong on anything, please let me know. But it really looks like they botched those specs up, and it is slightly annoying to me (assuming I'm correct) that nobody has corrected it.
There are in fact 2 scroll planes and 1 sprite plane; however, each plane has a priority bit that allows you to specify "high" priority or "low" priority. I forget the exact priority ordering, though. Also note that they say the Z80 isn't present in the MK-1631, aka Genesis 2, which is a stupid myth that's been perpetuated due to the lack of a Zilog chip on the board. I believe they built the Z80 into a custom ASIC in the MD2 (or used some other company's Z80). And yes, ROM space is definitely wrong. It's 4 MB (32 Mbit). (Though I've heard that with some tricks in the cartridge pinout, you can use 0x400000-0x7FFFFF for ROM data as well, which allows you to use 8 MB [64 Mbit] ROMs without bankswitching.) EDIT: They list the 32X as having a PCM chip. It most certainly does not - it has PWM. Crappier than PCM, but cheaper. EDIT 2: That site has lots of inaccurate information. Check out the NES (6508 CPU? It was a custom 6502 derivative, not a 6508) and other Sega consoles. Also, they list the Xbox as having a "X86-to-RISC Intel Pentium III or Celeron 733 MHz" CPU. "X86-to-RISC"?
Main system 68k: 7.67MHz in NTSC, 7.60MHz in PAL Z80: 3.58MHz (also it's present in all models, even model 3) ROM: 4MB (old official docs used to document only 1MB for some reason) 61 simultaneous colors max. without raster effects nor S/H Resolutions: 256x192, 256x224, 256x240, 256x448, 256x480, 320x224, 320x240, 320x448, 320x480 Planes: sprites plane, two scrolling tilemaps, one fixed tilemap (sharing same plane as one of the other tilemaps) Sound channels: 3 square waves, 1 noise channels, either 6 FM channels or 5 FM channels + DAC. Only FM and DAC can be panned. Not gonna comment on the other systems just in case I miss something =P But hell, 50,000 texture-mapped polygons per second in the 32x? Seriously? =/
The presence of Z80 depends on MD model, VA0, VA1 and VA3 have discrete Z80, in QFP not DIP package, and usually not by Zilog but usually Toshiba or a rebrand with Sega on it. VA2, VA4 and Genny3 do not have a discrete part, its integrated into the ASIC along with most other components. All that info came from Wikipedia what's on that site.... at least things are now more or less correct in Wikipedia thoguh there are some funny things in Memory section, especially the last sentence :P
X86-to-RISC? Oddly, it is accurate. From Pentium onwards most Intel CPUs don't actually run x86 code but RISC-like code which is translated from x86 code at runtime. Also AMD's do, iirc from the K5 onwards. The NES cpu is actually a 2A03, which is a 6502 without binary coded decimal operations and with integrated sound generation. The 6508 had an 8K-address space iirc, from $0 to $2000. Which doesn't make sense at all, because the NES accesses ROM memory usually from $8000 onwards, and it is not a mirror of anything below. Also, there's a loooot of wrong information about hardware on the internet, even on "documentation" sites, like NESDev. Some are pretty good some are so inaccurate that they're nearly unusable. Documentation about general purpose computers is even more lacking and incomplete.
Yeah, but saying it in relation to a console makes it look like it's a special feature only found on that console. It's redundant and confusing. The 6507 has the 8K address space. Its two most notable uses were in the Atari 2600 and Atari 810/1050 floppy drives. 6508 is a full 6502 with an internal 8-bit I/O port and 256 bytes of internal SRAM.
What? No. Judging from what info is it giving out, they took the info that were in those old FAQs made in the '90s, back when nobody without a license had idea how to program for the MD. I mean, it's the exact same values...
http://www.vgmuseum.com/systems/japn64/ Says the N64 has Ray Tracing. Thinking about it though, SGI designed the N64's chip set, so while it might not have been usable, it might have remained as some sort of legacy feature maybe? For the record, this isn't the only place I've seen make this claim.
or Wikipedia got its stuff from that site, but its unlikely as there are ton of other sites with identical information.... about 2 or 3 years ago, the Wikipedia had 1:1 stuff as what's on that site.
Well, as far as I know a small program is loaded onto the GPU which is used to render the polygons. Think on it as a really early shader hardware or similar. Though it was quite limited so raytracing would have been a pain to do on it, even if speed isn't taken into account.
Raytracing on an N64? After seeing how slow my many-more-times-powerful PC of today is at doing raytracing, that's either wrong or it was in no WAY real-time.
Like I said in my post, assuming it's there, it's probably a left over, assuming that the N64's chip set is based of a chip with Ray Tracing acceleration. Even the giant SGI boxes probably aren't capible of real time ray tracing, but for rendering stuff, being able to accelerate it would be useful, I imagine. Only a partnership as strange as SGI and Nintendo could make Ray Tracing a legacy feature. Regardless, I've never seen it mentioned anywhere that I consider credible on the subject, but it's possible that the credible sources didn't talk about it for being useless.
Unless they wrongly assumed that Ray Tracing = Ray Casting, which is definitely doable on a Nintendo 64.
The N64 doesn't have raycasting hardware AFAIK. Doom 64 is done with real polygons, despite the world is made with the rules used for raycasting (probably to avoid making a new physics engine).
You don't need special hardware to do ray casting. A 386 is enough to run Wolfenstain 3D, and it has been proven a 32X is enough too. They could definitely use ray casting on the Nintendo 64 if they wanted to.
