The origins of Sega's Model 2 arcade board, and, an interview with Real3D

[zyrobs]

A more powerful, more user friendly 32x, with good support and a long lifeline, would've been a viable upgrade path on it's own. On it's own. Not next to the Saturn.

Hitachi: SH7032 CPU RISC CHIP Running at 27 Mhz

Yeah, I'm pretty sure this was some journalistic cockup there. SH1s are rated for 20mhz max, SH2 is for 28mhz max (not counting later, faster versions). And the 27mhz could come from rounding up the 26.8mhz the Saturn was running at in 320/640px wide mode. Every other SH2 was marketed as 28mhz, while official descriptions of the Saturn said 28.6 / 26.8mhz.
I could imagine a billion different reason why they omitted the SH2, either they thought it was optional, not yet decided on, or they couldn't find any info on it so they only reported the cpu they knew to exist, etc etc...

Compared to the Saturn, it's expansion support was definitely on par with it, if not MORE comprehensive considering the relative complexity. Saturn has no provisions for adding more full-speed 32-bit SDRAM, MD cart bus can and does add RAM that's as fast or faster than onboard work RAM. Saturn can only expand bus A or B, at 16-bits wide on the cart bus, and 32-bits to bus A (I think) from the MPEG expansion port, and while memory can be relatively fast, actual RAM carts were slow.
The MD has expansion directly to the main CPU bus, and particularly wide on the cart slot (the entire 24-bit address range), though more limited on the side port.

But the Saturn doesn't need all of those fast ram expansions. It had the VDP2 external background pins mapped to the cart. That means it was invincible. It could have a Xbox on-a-cart plugged into it, sending digital video feed directly into the machine.

The MD on the other hand, was missing tons of things. VDP had a 128k VRAM mode, external palette input, both unused. And it had no viable upgrade path either - the extension port was literally a floppy connector (it is even marked as son on the schematics!), and there wasn't a proper way to mix in the Sega CD and 32x a/v either, without extra cables.

[MrSega]

"A more powerful 32x could have been even worse . . . assuming it WAS still like the 32x (a MD add-on), and would have conflicted worse with the Saturn itself moving forward. Having both didn't make sense . . . having a low-end expansion module for 3D and some other coprocessing (especially cheaper than 32x) made some sense to cater to a very different market segment than next-gen platforms, but the 32x didn't fall into that category completely, and a more complex/powerful/costly one would do so even less.

OTOH, if Sega wanted a cheaper, "more immediately accessible to mass market" next-gen console, that's another issue entirely (and the one major facet of the 32x's design goals that was impractical to accomplish as an add-on of any sort, at least with the Sega CD already on the market to further complicate hardware design logistics). If they wanted something cheaper than Saturn in general, then the Saturn should have been designed differently (and perhaps with provisions for modular expansion too), but from a 1994 perspective, the best option I can see for a "last minute" design to complement but not replace Saturn would have been the so-called "Jupiter." (cutting out the CD-ROM interface and drive should have cut a huge chunk of initial retail price and made it much closer to mainstream pricing in North America or Europe in 1994 and/or '95), and such a design would have been fully compatible with Saturn too. (CD-drive add-on could upgrade it, and all Jupiter carts could play on Saturn, not to mention potential games specifically adding more content to cart games with expansion CDs)"


@koolkitty89. I agree. Sega Jupiter deserved a serious look. Rather than being treated like a backup plan, SEGA of Japan should have forced their hand on SOA and made sure the Jupiter was the western top priority. I'm sure SOA thought it would be difficult trying to get Genesis dedicated American consumers to purchase an upgrade console. 32X was an unnecessary idea all on its own.The upgrade itself did nothing in improving Genesis' performance from the consumers perspective. All it did was confuse them. They also felt that Sega CD offered the best alternative when it came to an expansion accessory. I agree Jupiter cartridges along with running Model 1 engines and converters would have likely been cheap to produce and easy to program. Virtua Fighter would have ran flawlessly on Jupiter hardware as opposed to poorly on 32X. Jupiter wouldn't have had no problem being compatible with Genesis/Mega Drive carts. The internal SH-1 likewise would have perfectly ran the entire System 16 line without fuss and the pins could have simply just read the binary ROMs of System 16 and Mega Drive.

I also believe Jupiter would have brought SEGA some time to make upgrades and changes to Saturn. Releasing it 1994 for America and Europe would have given SEGA time to hurriedly develop the RAM cartridges that could also easily be fitted with CRX converters thus eliminating any VDP issues and overall lack of Middleware tools developers were having and giving the Saturn Model 2 Arcade perfect engines. Adding BC for both MD and Sega Jupiter to Saturn's cartridge expansion slot would have assured strong profit for SEGA.

Again, Jupiter was a smarter more viable solution that could have brought time for Saturn, Mars ended up being a disastrous mess that should have been aborted right from the start.

@zyrobs. I know. That's why the RAM Cartridges were vital and why it was a major mistake not marketing them as a top priority. The Saturn's design was to utilize expansion. It was dirt cheap producing the RAM carts which could easily be programmed to sent extra data to the SH-2 and VDPs and allow them to read different visual data and balance out off-the-shelf engines. This was the feature that made Saturn technically superior to PS1 and what Nintendo ultimately did with Nintendo 64's Ex paks.

[Vector2013]

VRD and VF on 32 X are arguably way better on 32 X than on Saturn. Imagine a Jupiter alone system, Mars stand alone Neptune, Saturn, MD + Sega CD and other stuff Sega had all selling at that time, would have been worse. I have no problem with the 32 X (Mars). I do agree the cart Saturn, Jupiter would have been cool though from things Mr Sega said, if.

"the best option I can see for a "last minute" design to complement but not replace Saturn would have been the so-called "Jupiter." (cutting out the CD-ROM interface and drive should have cut a huge chunk of initial retail price and made it much closer to mainstream pricing in North America or Europe in 1994 and/or '95), and such a design would have been fully compatible with Saturn too. (CD-drive add-on could upgrade it, and all Jupiter carts could play on Saturn, not to mention potential games specifically adding more content to cart games with expansion CDs)". Jupiter wouldn't have had no problem being compatible with Genesis/Mega Drive carts. "

[TrekkiesUnite118]

How would Jupiter not have problems being compatible with Genesis cartridges if all it is is a Saturn with no CD-ROM drive? It would still have the massive issue of not having any Genesis hardware to use for compatibility. At that point your looking into needing an adapter with the Genesis hardware built in, which could have been done on the Saturn just as easily.

[zyrobs]

A theoretical cartridge based Saturn would've ended up costing way more to develop for, and way more for each game, further alienating developers. See: N64.
Using a CD Drive for the Saturn was the best solution of the time.

The only major problem the Saturn had was that it was badly supported, and killed too soon.

[Vector2013]

It would still have the massive issue of not having any Genesis hardware to use for compatibility. At that point your looking into needing an adapter with the Genesis hardware built in, which could have been done on the Saturn just as easily.

Why didn't Sega make one then ? It would have helped sales imo.

[TrekkiesUnite118]

Why didn't Sega make one then ? It would have helped sales imo.

It might have cost too much still. It's not like the Power Base Converter where it's just a Pass-Through device. This would have required putting the entire Genesis in that Cartridge Adapter.

[zyrobs]

In theory, I think it would've been possible to make a Saturn cart that provided backwards compatibility. It would have had the entire MD hardware inside though. If it could syphon enough power from the Saturn cart slot, it could probably work. You know, when the Saturn cart port was working.

[MrSega]

In theory, I think it would've been possible to make a Saturn cart that provided backwards compatibility. It would have had the entire MD hardware inside though. If it could syphon enough power from the Saturn cart slot, it could probably work. You know, when the Saturn cart port was working.

I thought a simple BC solution would have been to do what SEGA did for Pioneer's LaserActive, (program a BIOS for System 16 and MD ROMs to be readable) on Saturn hardware. Pioneer and SEGA's simple solution was to simply sell an EM Module with MD and Mega CD's BIOS, but what option did SEGA have with Saturn's expansion cartridge design that simply could have been a cheaper loophole around the LaserActive idea?

[TrekkiesUnite118]

I thought a simple BC solution would have been to do what SEGA did for Pioneer's LaserActive, (program a BIOS for System 16 and MD ROMs to be readable) on Saturn hardware.

It has nothing to do with Bios at all. The Laseractive PACs have the actual hardware built into them. Without the PACs, you can't play any Genesis, Sega CD, PC-Engine, or PC-Engine CD games at all.

Probably the most elegant solution would have been to try and put the Genesis and Sega CD hardware into something that could have gone into the MPEG card slot. Getting the Sega CD hardware in there might have been tough, but they could have probably squeezed the Genesis onto it without much trouble. Then you would just need a pass-through adapter for cartridges.

[zyrobs]

I thought a simple BC solution would have been to do what SEGA did for Pioneer's LaserActive, (program a BIOS for System 16 and MD ROMs to be readable) on Saturn hardware.

That makes absolutely no sense whatsoever.
I don't think you have the slightest grasp of the topic.

Probably the most elegant solution would have been to try and put the Genesis and Sega CD hardware into something that could have gone into the MPEG card slot. Getting the Sega CD hardware in there might have been tough, but they could have probably squeezed the Genesis onto it without much trouble. Then you would just need a pass-through adapter for cartridges.

There wouldn't have been enough space in the MPEG card slot, to fit in a full Megadrive circa 1994, let alone Mega CD. The only thing at the time of comparable size was the Nomad, so think along those lines.
Full Megadrive system-on-chip ASICs were achieved by 1998, but backwards compatibility would've have been moot point by then... well, maybe not if the Saturn got enough support to keep it alive as long as the PS1.

[MrSega]

That makes absolutely no sense whatsoever.
I don't think you have the slightest grasp of the topic.


There wouldn't have been enough space in the MPEG card slot, to fit in a full Megadrive circa 1994, let alone Mega CD. The only thing at the time of comparable size was the Nomad, so think along those lines.
Full Megadrive system-on-chip ASICs were achieved by 1998, but backwards compatibility would've have been moot point by then... well, maybe not if the Saturn got enough support to keep it alive as long as the PS1.

How exactly did the LaserActive read MD carts then? I seem to recall using Expansion modules that could read Mega Drive ROMs and Mega CD discs.


"The LaserActive could not play games as a stand alone system - it requires expansion modules called PAC units. The following is a list of the modules that were released (US release \ Japan release) and their respective description:
Sega PAC (PAC-S10 \ PAC-S1) : Allows play of any Sega Genesis, Sega CD, Mega LDs (specifically designed Sega games release on the Laserdisc format) games and CD+G discs. Formally known as the Mega-LD pack.

"The modules slide into the system on the left hand, bottom side of the main LaserActive system. The power must be turned off when switching out expansion PACs. There is a manual eject button that resides on the front of the unit that facilitates this function. Inserting modules into the system is rather delicate, or so it feels. They do snap into place firmly, but the weight alone of the PAC units tends to make one a bit cautious while doing so. The two game PACs came with the appropriate, Pioneer logo-stamped game controller."

Without native MD hardware and since the Motorola sound processor inside the Saturn is MD's recycled CPU, wasn't there a way for Saturn hardware(Its SH-2 processors) to read System 16/Mega Drive ROMs?

[zyrobs]

The Laseractive Sega PAC had all of the Megadrive and Mega CD hardware built into it. Not just the 68k and a BIOS, but all the custom video and audio chips, etc. The entire thing.

System 16 compatibility was impossible, that thing used completely different display hardware. Same for the Saturn reading Megadrive/System 16 stuff.

The 68k in the Saturn was different from the one in the Megadrive. It wasn't recycled; it was put there as a sound CPU because it was cheap, efficient, and familiar for developers. Ironically, one thing the developers never did was code the 68k side, as all but a handful few games used Sega-supplied sound drivers...

[MrSega]

The Laseractive Sega PAC had all of the Megadrive and Mega CD hardware built into it. Not just the 68k and a BIOS, but all the custom video and audio chips, etc. The entire thing.

System 16 compatibility was impossible, that thing used completely different display hardware. Same for the Saturn reading Megadrive/System 16 stuff.

The 68k in the Saturn was different from the one in the Megadrive. It wasn't recycled; it was put there as a sound CPU because it was cheap, efficient, and familiar for developers. Ironically, one thing the developers never did was code the 68k side, as all but a handful few games used Sega-supplied sound drivers...

I see. So the LaserActive Mega LD PAC had all the full components of Mega Drive.

Could it be that in 1993-1994, there simply wasn't an binary(in this case a MD software kit) or bios solution for Mega Drive ROMs to be readable on Sega's System 32 and System 24 parts or on the SH-2?

[TrekkiesUnite118]

I see. So the LaserActive Mega LD PAC had all the full components of Mega Drive.

Could it be that in 1993-1994, there simply wasn't an binary(in this case a MD software kit) or bios solution for Mega Drive ROMs to be readable on Sega's System 32 and System 24 parts or on the SH-2?

You can't just throw a bios in and hope it makes the game work. You need the hardware. There are only two ways to get backwards compatibility. The first is Emulation, which the Saturn isn't powerful enough to pull off effectively. The 2nd is include the Hardware in the system itself. This is what the Genesis does for Master System compatibility and what the PS2, early PS3, GBA, DS, 3DS, Wii, and Wii U do. The 360 uses a mix of emulation and reprogramming of select games to make them work. That's why when you throw an original Xbox game into a 360 you need to download a patch for it. However this is made easier since the Xbox and 360 are based on PC architecture.