How exactly did SNK arrive at "330 megabit" for Neo Geo ?

Discussion of development of software for any "obsolete" computer or video game system. See the WSdev wiki and ObscureDev wiki for more information on certain platforms.
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

How exactly did SNK arrive at "330 megabit" for Neo Geo ?

Post by lidnariq »

I know it's just marketing, but digging through the information on wiki.neogeodev.org has left me confused.
Espozo wrote:a non "GIGA POWER" Neo Geo game is at most 330 mega bits
How exactly did they arrive at 330 megabit?

( https://wiki.neogeodev.org/index.php?title=NEO-273 )

On the CHA board, ignoring any on-cart bankswitching:
The original Neo Geo C ROM layout nominally supports 2 Mi x 32bit, for 64 Mibit of sprite data.
The revised memory layout one uses the entire 24-bit P bus (plus CA4) to support 16 32 Mi x 32bit, or 512 1024 Mibit of sprite data.
128 KiB (1Mibit) are always used for the S ROM (fix layer).
Z80: one 64 Ki x 8 bit (512 Kibit; M ROM) for the sound driver

On the PROG board, again ignoring any on-cart bankswitching:
68k: 512 Ki x 16bit (8 Mibit; P ROM), plus a bonus nonadjacent 512 Ki x16bit that I guess they weren't counting?
YM2610: two 16 Mi x 8 bit (total 256 Mibit; V ROM)

so ... 256 Mibit(V) + 64 Mibit(C) + 8 Mibit(P) + 1 Mibit(S) + ½ Mibit(M) = 329½ Mibit? Is that what they were thinking?
Last edited by lidnariq on Mon Aug 15, 2016 4:32 pm, edited 1 time in total.
psycopathicteen
Posts: 3140
Joined: Wed May 19, 2010 6:12 pm

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by psycopathicteen »

You mean to tell me, that most of it was for sound?
User avatar
Drew Sebastino
Formerly Espozo
Posts: 3496
Joined: Mon Sep 15, 2014 4:35 pm
Location: Richmond, Virginia

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by Drew Sebastino »

That's surprising to me too. I mean, it's pretty crazy for the PCM/FM setup, but not enough for just streaming sound tracks. The only thing I can think of is for doing the former, but with dialogue, (beyond "oomph") but how often is that used in an arcade game? Even voice samples in a fighting game aren't long enough to use that much data. At least I know why "GIGA POWER" games came into existence though, because had you been able to use those "330 megabits" of data however you wanted to, Metal Slug 3 would not need bank switching. (I guarantee it's that not all the tile data fit into a regular cartridge)
ccovell
Posts: 1045
Joined: Sun Mar 19, 2006 9:44 pm
Location: Japan
Contact:

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by ccovell »

At the launch of the Neo-Geo, most of SNK's own NG games had rather drab graphics, but tons of voice samples. That's obviously what they were trying to push at the start.
User avatar
Gilbert
Posts: 564
Joined: Sun Dec 12, 2010 10:27 pm
Location: Hong Kong
Contact:

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by Gilbert »

I think some of the earlier games had background songs playing (an early mahjong game was possibly an example, if my memory is correct), probably not streamed entirely, but with chip synthesized music coupled with recorded vocal (like the opening to Tales of Phantasia for the Super Famicom).

When SNK designed the console, they might have thought of Psycho Soldier.
User avatar
Drew Sebastino
Formerly Espozo
Posts: 3496
Joined: Mon Sep 15, 2014 4:35 pm
Location: Richmond, Virginia

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by Drew Sebastino »

Gilbert wrote:When SNK designed the console, they might have thought of Psycho Soldier.
God, that music is terrible... :lol:
ccovell wrote:At the launch of the Neo-Geo, most of SNK's own NG games had rather drab graphics, but tons of voice samples. That's obviously what they were trying to push at the start.
I think a lot or people have forgotten how mediocre most Neo Geo games looked for the couple of years or the systems life. The following don't look like anything that wasn't done already done on the SNES, and would certainly be possible if it weren't for BG (that actually seemed more emphasized in the earlier titles) than scrolling in some of the games.

Image

Image

Image

I don't think it was until 1995 that Neo Geo games started to look consistently good. Really, the Neo Geo doesn't have seemed to be any more powerful than the other arcade boards of the era. Well, I actually don't know, because although the number of pixels it can display horizontally including overdraw is most likely lower than its closest (as in year made) competitor I can think of, the Irem M92, (unless Mame's Irem M92 driver accuracy is the problem, somehow Gunforce II never experiences sprite pixels per scan line problems) (CPS1 was made significantly earlier, and the CPS2 was made significantly later. Konami makes a new system for every game, and Sega had a million different arcade boards, with the ones being put into production at that time probably costing as much as an amusement park ride) it's also more than likely streaming more data required to get all that stuff to display in the first place considering you're dealing with only sprites that have more data than a simple background tile. If this sets it over the M92's bandwidth is a mystery to me though. I still think the fix layer is a waste of perfectly good bandwidth. You could have used it towards sprites, which it then wouldn't have enough bandwith to cover the width of the screen like the fix layer, but I mean, come on. Actually, even in later games, the lack of "BG layers" is odd. Aside for some freak situations, I can't even think of a time any game routinely pushes the bandwidth to even 3/4s.
User avatar
mikejmoffitt
Posts: 1353
Joined: Sun May 27, 2012 8:43 pm

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by mikejmoffitt »

Espozo wrote: I think a lot or people have forgotten how mediocre most Neo Geo games looked for the couple of years or the systems life. The following don't look like anything that wasn't done already done on the SNES, and would certainly be possible if it weren't for BG (that actually seemed more emphasized in the earlier titles) than scrolling in some of the games.
These games pre-dated the SNES. Neo-Geo is a product of the late '80s 1990, though these games were no doubt created in late '89 or so. Even the earlier games had a lot of animation and unique tiles as well.
tepples
Posts: 22708
Joined: Sun Sep 19, 2004 11:12 pm
Location: NE Indiana, USA (NTSC)
Contact:

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by tepples »

mikejmoffitt wrote:
Espozo wrote:I think a lot or people have forgotten how mediocre most Neo Geo games looked for the couple of years or the systems life.
These games pre-dated the SNES. Neo-Geo is a product of the late '80s 1990
So is the Super Famicom. The graphics of games released in comparable years may have looked similar. Adapting to a more detailed art style is a matter not only of hardware but also of artist labor, and that might explain progression in parallel until the Super Famicom's ceiling was hit. The Neo Geo had a bit more headroom for games that played to its strengths. In 1995, investment in graphical complexity on the Super NES started to tail off as 2D developers shifted to the Saturn and whatever PlayStation games Sony didn't block under its deprecation of 2D.
User avatar
Drew Sebastino
Formerly Espozo
Posts: 3496
Joined: Mon Sep 15, 2014 4:35 pm
Location: Richmond, Virginia

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by Drew Sebastino »

tepples wrote:until the Super Famicom's ceiling was hit
"Practical" ceiling. :lol: Although to be fair, I don't know of any Neo Geo games that push the system any harder than what the hardest games did on the SNES, so I'm sure there's extra room for improvement on the Neo Geo too, maybe just not quite as much. The specs of the Neo Geo seem a lot more "static" than the SNES's in that there are no BG modes, transparency, or vram, but the fact that you can essentially split the balance between background layers and sprites any way you want definitely combats that. Does the Neo Geo have any raster effects, because I imagine that would help too. I'm only asking because I haven't seen any. I'd say I think the other problem in the Neo Geo not looking as good as the hardware would suggest compared to the SNES is that some of the limits of the Neo Geo are so high that they never even come close to being hit. Although the Neo Geo has 16x the number of palettes as the SNES, most games I've seen don't look like they ever go over 2x the amount because why would you need to really. You're sure as hell not needing to do any of this: viewtopic.php?f=12&t=14662 Of course, I'm a big SNES fanboy, so don't take all of what I said earlier to seriously. :lol: One thing that I probably disagree with a lot of people is that I think the SNES's color count is kind of lame. I mean, if you take any popular arcade machine from the day and compare its bandwidth to the SNES's, it's just like 2-4 times as high. However, you compare the number of palettes, and it's like 8-16 times as high. The thing is that the number of palettes is too low to give every object their own palette, but kind of too high to go the NES and Genesis approach of just having all the palettes sit there. Donkey Kong country can pull it off in that there aren't many different types of objects onscreen at a time, or even that many objects onscreen in general, but for something like a run and gun with a bunch of random stuff, this kind of falls apart. I'm sure most people would say the DKC games are just as colorful as the Metal Slug ones, but it only looks like it because every object has their own unique palette, but there are just more objects in a Metal Slug game.
User avatar
freem
Posts: 176
Joined: Mon Oct 01, 2012 3:47 pm
Location: freemland (NTSC-U)
Contact:

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by freem »

Espozo wrote:The specs of the Neo Geo seem a lot more "static" than the SNES's in that there are no BG modes, transparency, or vram, but the fact that you can essentially split the balance between background layers and sprites any way you want definitely combats that.
On cart systems, you're only limited by whatever you put in the cartridge hardware. You're right that there's no BG modes (only sprites and the fix layer) or transparency (needs to be faked with 60hz alternating checkerboards)
Espozo wrote:Does the Neo Geo have any raster effects, because I imagine that would help too. I'm only asking because I haven't seen any.
Neo Turf Masters heavily uses raster effects for rendering, as does Riding Hero. Some other games only really use it for effect (the house on fire stage in Last Blade 2 comes to mind).
Espozo wrote:I'd say I think the other problem in the Neo Geo not looking as good as the hardware would suggest compared to the SNES is that some of the limits of the Neo Geo are so high that they never even come close to being hit. Although the Neo Geo has 16x the number of palettes as the SNES, most games I've seen don't look like they ever go over 2x the amount because why would you need to really.
Plus, managing the large number of palettes can be a pain in the ass (I'd imagine the developers of Ragnagard know a lot about this). This goes double when you realize the only "safe" time you can change palettes is during VBlank.
ccovell
Posts: 1045
Joined: Sun Mar 19, 2006 9:44 pm
Location: Japan
Contact:

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by ccovell »

Espozo wrote:
Gilbert wrote:When SNK designed the console, they might have thought of Psycho Soldier.
God, that music is terrible... :lol:
ccovell wrote:At the launch of the Neo-Geo, most of SNK's own NG games had rather drab graphics, but tons of voice samples. That's obviously what they were trying to push at the start.
I don't think it was until 1995 that Neo Geo games started to look consistently good.
I disagree. Even some 1990/1991 games on the Neo had great graphics, basically far more varied graphical tiles compared to the SFC, thanks to gluttonous ROM space on Neo carts; as well as far more sprites (well, the Neo is essentially all sprites) for incidental effects. Anyway, in my post, I criticized only SNK-developed titles, because games from Alpha Denshi, Pallas, Sammy, etc. had some great graphical design and colour use.

By the way, the Neo-Geo hardware was originally designed by Alpha Denshi (check Wikipedia for info), and SNK did the manufacturing and marketing. (Thus, I doubt if Psycho Soldier was on their minds...)
tepples
Posts: 22708
Joined: Sun Sep 19, 2004 11:12 pm
Location: NE Indiana, USA (NTSC)
Contact:

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by tepples »

Would GBA be about as powerful as Neo Geo, apart from the smaller display (240x160 vs. 304x224)?
  • 16.78 MHz ARM7TDMI CPU performs both game logic and audio mixing
  • Similar typical sample rate (18 kHz)
  • 4 scrolling tiled background layers, with each pair replaceable by a tiled rot/scale layer
  • 64K of VRAM for backgrounds: 2-4K per "normal" background, with the rest for tiles
  • 128 sprites, with OAM writable during hblank for soft multiplexing
  • 32K of VRAM for sprites, with conveniently fast DMA from ROM and WRAM
  • Flexible sprite sizes 8x8-32x32, plus 64x64, 64x32, and 32x64, in both Genesis-style 1D and Super NES-style 2D layouts
  • 4x overdraw for unscaled sprites (scaled sprites take about 2.5x as long)
  • 16 background palettes and 16 sprite palettes (like TurboGrafx-16), writable at any time
  • Game Pak up to 32 MiB (256 Megabits), plus 256 KiB auxiliary work RAM for decompressed tile data or multiboot client for players 2-4
User avatar
freem
Posts: 176
Joined: Mon Oct 01, 2012 3:47 pm
Location: freemland (NTSC-U)
Contact:

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by freem »

tepples wrote:Would GBA be about as powerful as Neo Geo, apart from the smaller display (240x160 vs. 304x224)?
Going point by point...
tepples wrote:16.78 MHz ARM7TDMI CPU performs both game logic and audio mixing
GBA wins here, easily, as far as I'm concerned. The CPUs in the Neo-Geo are a 68000 (main) and a Z80 (audio).
tepples wrote:Similar typical sample rate (18 kHz)
This is a push, unless you count the Neo-Geo cart system's ADPCM-B channel, which has a variable sampling rate. However, it's not available on Neo-Geo CD systems.
tepples wrote:4 scrolling tiled background layers, with each pair replaceable by a tiled rot/scale layer
GBA wins, since Neo-Geo has no rotation or upward scaling (scaling down is possible). Also, no layers; all backgrounds are made of sprites, eating into the 96 sprites/scanline limit.
tepples wrote:64K of VRAM for backgrounds: 2-4K per "normal" background, with the rest for tiles
and
tepples wrote:32K of VRAM for sprites, with conveniently fast DMA from ROM and WRAM
VRAM on Neo-Geo isn't really comparable with other systems, as it doesn't hold the actual graphics data. There's 68KiB available (split into 64KiB and 4KiB), which is split between sprite definitions and the fix layer tilemap.

As far as I know, there's no DMA on Neo-Geo cart systems, but the CD system has DMA for sending data to its RAM chips. Section RAM sizes will be explained later.
tepples wrote:128 sprites, with OAM writable during hblank for soft multiplexing
380 usable sprites; I'm not sure if multiplexing works at all.
tepples wrote:Flexible sprite sizes 8x8-32x32, plus 64x64, 64x32, and 32x64, in both Genesis-style 1D and Super NES-style 2D layouts
The core Neo-Geo sprite size is 16px wide, and 16-512px tall. Graphics are stored in 16x16 chunks.
tepples wrote:4x overdraw for unscaled sprites (scaled sprites take about 2.5x as long)
Not sure how to compare this one.
tepples wrote:16 background palettes and 16 sprite palettes (like TurboGrafx-16), writable at any time
2 banks of 256 palettes, 16 colors each. Only one bank can be active at a time. The first 16 sets of palettes can be used by the fix and sprite layers. The remaining palettes can only be used by sprites.
tepples wrote:Game Pak up to 32 MiB (256 Megabits), plus 256 KiB auxiliary work RAM for decompressed tile data or multiboot client for players 2-4
Cart systems have the following limits, without bankswitching:
P (program) ROM theoretical maximum - 2MiB
C (character) ROM theoretical maximum - 128MiB ("if you're planning a Neo-Geo game with more than 128MiB of graphics, find another system")
V (sound) ROM theoretical maximum - 16MiB
M (music driver) ROM theoretical maximum - 62KiB ($F800-$FFFF used as RAM area)
S (fix layer) ROM theoretical maximum - 128KiB
(I hope that's right; got the info from here.)

Cartridges can include extra hardware used for banking, multiplayer (chip specifics), or other functionality.

CD games have different numbers, since the CD system's RAM only allows a certain amount to be loaded at once:
Program - 2MiB
Sprites - 4MiB
ADPCM/sound samples - 1MiB
Fix Tiles - 128KiB
Sound Driver - 64KiB
tomaitheous
Posts: 592
Joined: Thu Aug 28, 2008 1:17 am
Contact:

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by tomaitheous »

Mi and Ki notation? Has it really come down to needing to use these terms when referring ram/rom/memory? I mean, it might be a bit more accurate than Mbit/Mbyte or whatever, but it was always understood at what was being stated (binary based system). Just wanted to make an observation that its popularity has been on the rise in the past few years (from what I've seen on forums). Makes me chuckle when people spell out mebibyte or kibibit; like a kindergartener mispronouncing a word.
__________________________
http://pcedev.wordpress.com
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: How exactly did SNK arrive at "330 megabit" for Neo Geo

Post by lidnariq »

If you have a chance to prevent confusion or an argument about definitions, why not take it?
Post Reply