Winning the Console Wars – An In-Depth Architectural Study

From time to time, we at Hackaday like to publish a few engineering war stories – the tales of bravery and intrigue in getting a product to market, getting a product cancelled, and why one technology won out over another. Today’s war story is from the most brutal and savage conflicts of our time, the console wars.

The thing most people don’t realize about the console wars is that it was never really about the consoles at all. While the war was divided along the Genesis / Mega Drive and the Super Nintendo fronts, the battles were between games. Mortal Kombat was a bloody battle, but in the end, Sega won that one. The 3D graphics campaign was hard, and the Starfox offensive would be compared to the Desert Fox’s success at the Kasserine Pass. In either case, only Sega’s 32X and the British 7th Armoured Division entering Tunis would bring hostilities to an end.

In any event, these pitched battles are consigned to be interpreted and reinterpreted by historians evermore. I can only offer my war story of the console wars, and that means a deconstruction of the hardware.

An Architectural Study of the Sega Genesis and Super Nintendo

The traditional comparison between two consoles is usually presented as a series of specs, a bunch of numbers, and tick marks indicating which system wins in each category. While this does illustrate the strengths and weaknesses of each console, it is a rhetorical technique that is grossly imprecise, given the different architectures. The usual benchmark comparison is as follows:

Specs

Conventional wisdom – and people arguing on the Internet – tells you that faster is better, and with the Sega console having a higher clock speed it’s capable of doing more calculations per second. Sure, it may not be able to draw as many sprites on the screen as the SNES, but the faster processor is what allowed the Genesis / Mega Drive to have ‘faster’ games – the Sonic series, for example, and the incredible library of sports games. It’s an argument wrapped up in specs so neatly this conventional wisdom has been largely unquestioned for nearly thirty years. Even the Internet’s best console experts fall victim to the trap of comparing specs between different architectures, and it’s complete and utter baloney.

Let’s take a look at one of these numbers – the CPU speed of the SNES and the Genesis/Mega Drive. The SNES CPU, a Ricoh 5A22 is based on the 65C816 core, an oft-forgotten 16-bit offshoot of the 6502 and related chips found in everything from the Apple II, Commodore 64, and even the original Nintendo NES. The 5A22 inside the SNES is clocked at around 2.68 MHz for most games. The Sega used a 68000 CPU clocked at 7.67 MHz. By comparing just these two numbers, the SNES wins, but this isn’t necessarily the truth.

In comparing the clock speed of two different CPUs, we’re merely looking at how frequently the bus is accessed, and not the number of instructions per second.

In the 68000, each instruction requires at least eight clock cycles to complete, whereas the 65C816 – like it’s younger 6502 brother – could execute an instruction every two or three clock cycles. This means the Sega could handle around 900,000 instructions per second, maximum. The SNES could compute around 1.7 Million instructions per second, despite it’s lower clock speed.

Even though the Sega console has a faster clock, it performs fewer instructions per second.

And so we come to the crux of the argument; the statistics of the great console wars, while not wrong, are frequently misinterpreted. How then do we decide an outcome?

The Architecture of the Sega Genesis / Mega Drive

genesis_block_diagram
While the Sega Genesis/Mega Drive is usually cited as having a 68000 CPU, this isn’t a complete picture of what’s going on inside the Sega console. In effect, the Genesis is a dual-processor computer with two CPUs dedicated to different tasks. The 68000 handles game logic and graphics, but surprisingly not much else. A Z80 — a CPU introduced a decade before the Genesis/Mega Drive — is used for reading the state of the game pads, and playing audio.

Interestingly, the Sega Genesis / Mega Drive contains most of the components of Sega’s earlier console, the Sega Master System. With the addition of a Power Base Converter, Master System games can be played while the 68000 CPU is in idle.

The  Architecture of the Super Nintendo

SNES-BLOCK-DIAGRAM

The SNES is a different beast entirely. Everything is controlled through the 5A22 / 65816 CPU. The controllers are fed right into the data lines of the 5A22, and DMA instructions are able to shuttle data between the two slightly different Picture Processing Units.

An interesting difference between the two consoles are the connections between the cartridge slot and various peripheral chips. Nearly the entire cartridge connector of the Sega machine is dedicated to the address and data lines for the 68000 CPU. While there are a few control signals thrown in, it’s not enough to allow the cartridge direct access to the video display unit or the FM synthesis chip.

The cartridge connector for the SNES, on the other hand, has direct access to one picture processing unit and the audio processor. The exploitation of this capability was seen in games ranging from Star Fox with it’s SuperFX chip, to Mega Man X games with its math coprocessor, to Super Mario RPG: Legend of the Seven Stars and its Super Accelerator 1 chip that is basically an upgraded version of the main SNES CPU, the 5A22.

Comparative designs, and who won the console wars

Time to make a holistic analysis of each competing platform. By far, the SNES is a more capable console; its cartridges are able to send data directly to the PPUs and audio processors, it’s faster, and there’s more work RAM, vRAM, and audio RAM.

The Sega 'Tower of Power'. Image credit /u/bluenfee
The Sega ‘Tower of Power’. Image credit /u/bluenfee

The Genesis / Mega Drive may be seen as more expandable thanks to the Sega CD (the first CD-ROM based game console, the Sega 32X), an upgraded coprocessor for the Genesis, backwards compatibility with a Master System Power Base converter, and a number of strange cartridges like Sonic and Knuckles with ‘lock-on’ technology. However, it’s actually the SNES that is more expandable. This is most certainly not the conventional wisdom, and the difference is due to how expandability was implemented in each console.

To add additional capabilities to the SNES, game designers would add new chips to the game cartridge. Star Fox famously exploited this with the SuperFX chip, and the list of SNES enhancement chips is deserving of its own entry in Wikipedia.

In comparison, the Genesis / Mega Drive could only be expanded through kludges – either through abusing the ASIC chip between the 68000 and Z80 CPUs, or in the case of the 32X add-on, bypassing the video display unit entirely.

In any event, this is purely an academic exercise. Games sell consoles, and Nintendo’s IP portfolio – even in the early 90s – included characters that had their own cartoons, live action movies, and cereals.

While this academic exercise is completely unimportant today – there probably won’t be a game console that ships with cartridges any more – it is an interesting case study on extendable computer design.

53 thoughts on “Winning the Console Wars – An In-Depth Architectural Study

    1. It’s often forgotten that “Blast Processing” was a real thing. It was a technique the programmers could use for a short term boost in processing speed. To be honest I don’t quite remember how it worked exactly, but that’s more than the marketing guys understood.

    1. Back then (1991), PCs really really sucked when it came to graphics (no sprites except for the mouse cursor) and audio (one channel square wave). The Commodore 64 could still beat the PC in ’91 when it comes to games. And don’t make me mention the Amiga.

      Commodore does what Nintendon’t.

        1. Much more appealing to me, amiga cd32. Fairly well understood architecture, easy to code for, no crappy drm or copy protection on the discs to spoil you being able to make your own and nice little tidy package to sit under the tv.
          I used to write demos and game software on the a500, and later on went to make the jump to x86 and it was just a fragmented mess after the relative hardware stability of the amiga. Still my favourite console in my collection.
          Its just a damn shame that commodore’s management couldnt organize a pish up in a brewery around that period or we could have seen a fairly open machine on the market to tinker with a lot longer, it shifted 100,000 units in europe alone, then mis management managed that whole stuck in a warehouse leading to bankrupcy debacle and it never even made the US market.

          Never really got into the whole having to have a game cartridge thing on the snes, and sega sort of passed me by then too as didn’t see that much of a homebrew scene in comparison to the amiga etc. I dont remember having any real enthusiasm for consoles until the 3d0 launched with need for speed and Zarch (aka virus) on the jaguar was pretty interesting as I had been rather addicted to elite on the c64 also by david braben, and then the ps1 arrived with its easy to defeat disc protection schema around the time of cheap scsi cdrecorders which lead to the homebrew scene lighting up once more and into the original xbox which was basically a rather bespoke minimal pc inside once you got in. I still have a free mcboot’d ps2 + wii that can run homebrew.
          My collection starts with a radeon tele-sports bat n ball machine and some pre jamma arcade machines and stops at the ps3 and 360 era, wife asked me if I want a ps4 or xbox one for xmas and the answers no. Not interested in consumer devices without much modding possibilities and I can’t imagine being able to get hold of a dev kit and hit the hardware on anything as locked down as a modern console so for me there it ends. Pity as a modern cel processor appeals after having had a play with ppc’s (genesi not mac…) after the amiga too.

          1. How wasn’t the Amiga a clusterfuck when it came to upgrades and expansions?

            You had ten different types of RAM, slow, fast, and different chips doing half the job of the other chip in a criss-cross fashion, and when you added some expansion you’d have to turn off another…

      1. “Commodore does what Nintendon’t.”

        As a Commodore girl and a Sega chick, this makes me happy. I was an extremely happy kid (having gotten my C64C when I was five, and my Genesis Model 1 when I was 10), what with my glory days of Sonic and Vectorman and MicroMachines Racing. And of course, I never stopped playing Jumpman and Ultimate Wizard.

  1. We have to consider development costs. Nintendo had 90% of the console market with Nes/famicom, and money to develop a huge project. Sega made genesis with non-sold parts of sms and some arcade machines. Its simpler, and direct.

    1. Actually, Sega was way more willing to take risks in hardware design. Yamauchi blocked any attempt to do new things (hardware-wise), “old, cheap, well tested components used in new creative ways” was their trademark. Historically, Nintendo almost never spent that much money creating their new consoles, GameCube being probably the only exception and the crappy “red-only not-that-portable” VirtualBoy the clearest example of the bad consequences.

  2. Super Mario kart on the SNES, the best multiplayer driving game ever.
    Drifting before drifting was cool.
    We played that to death and perfection. One single slip up would cost you the race.
    No “catch up” mode or other player helpers. Pure seat of the pants skill and weaponry bonus.

  3. I should note that the Sega CD and 32x were different devices (I think you were trying to say that above, but it’s garbled).

    Also, I find it interesting how both the Genesis/MD and the Playstation2 handle backward compatibility. They’re both essentially the previous gen’s console with a more powerful computer tacked on. But the older hardware is still needed for stuff like reading the controllers and audio.

  4. Nice reference to the Gear Wars from Rick & Morty.

    …oh wait, was the R&M ref a callback to something else? Oh no… hipster cred failing… too much parent time…

    I really enjoyed reading this. I’d love to see more comparative breakdowns of common media appliances.

  5. I love it when “historians” reinterpret history!

    It happens in every field of endeavor, whether it be “the north could have won at Gettysburg with bows and arrows and had nothing to do with the greater range of rifled versus smooth bores” or the Apollo program was just a “west versus east” pissing contest.

    Nintendo “won” because of Mario and those dumb “fighting” games, nothing else and they are still flogging that deceased equine.

    A console platform lives or dies on its fanbase, little twats don’t give a rats ass what is “under the hood”.

    I’ve been “gaming” since the very beginning, I’m talking “Pong” here, the original one done in 7400 TTL, not the AY-xxxx chip.
    Those first consoles that HAD the AY-xxxx chip, switch selectable to play a couple of bat and ball games, maybe with a light pen style “pistol” to “shoot” shit with, sold like hot cakes, then died out.

    Then we had Space Invaders (shudders) that folks would play for hours.

    Things progressed, sorta, my first job out of high school was in a 1980’s video game arcade, I still had to maintain Pong and Space Invader machines well into the 1990’s!!!

    Sheeple like what is familiar, it doesn’t matter if it’s any good (this is why ford can sorta still sell cars).

    The Nintendo arcade machines were popular, they managed to translate that commercial success into the console market in a way that Sega or Atari (remember them??) never did.

    Anyone remember Exidy? The Exidy Sorcerer???
    The couple of arcade games Exidy had were kinda ok, the console was kinda ok,

    Anyone remember the Fairchild F8 console??
    Same deal, the only reason game arcades “worked” was the hardware was better than what most of us could afford at home, when a console is about as good as what you could play in an arcade, why bother?
    Atari tried to make a (terrible) home computer system, then tried to sell it as a console without a keyboard.

    The number of times I’ve had arguments with idiots over “Sega is lame, Nintendo is better” is staggering, it’s like the whole iThing crap, almost like a religion, “it’s better because it is”, no logic, just “passion”.

    1. yawn, crazy old man that with excellent points, but invalidates own point with bad analogy that is objectively false. “this is why ford can sorta still sell cars.” Ford can sorta still sell cars because of excellent timing with respect to organizational changes and extremely prudent manufacturing investments. yea yea your gut tells you only immune he-mans of yore can see through the drivel that dominates the “sheeple” decision making process.

    2. I love it when “literates” reinterpret a post.

      “Nintendo “won” because of Mario and those dumb ‘fighting’ games, nothing else and they are still flogging that deceased equine.

      A console platform lives or dies on its fanbase, little twats don’t give a rats ass what is ‘under the hood’.”

      FTA:
      “In any event, this is purely an academic exercise. Games sell consoles, and Nintendo’s IP portfolio – even in the early 90s – included characters that had their own cartoons, live action movies, and cereals.”

      You’re shitting on him for saying the exact same thing as you. Except he has eloquence, you have misplaced anger.

      Sheeple: Following the herd while believing that you’re pretty a special snowflake.

      1. This. Besides, Nintendo “won” because of the controller. We liked the blood in MK on the Genesis, but it wasn’t enough to counter only having 3 buttons (forget the 6 button thing they tried… the layout works great in an arcade machine (ala Street Fighter), but didn’t translate well to a handheld controller, IMHO).

        The shoulder buttons on the SNES controller are what did it for me. Easy blocking in MK and we got so good with SFII that we regularly had one-handed “tournaments” where you held the controller against your cheek and just used the d-pad and left shoulder.

      1. the Atari ST was a great machine!

        I’m talking about the 400 with the membrane keyboard and the 800, both of which had a 6502.
        The ST was a 68000 machine and much under rated, if I bothered I could dust off the couple I have in storage.

        ps

        I’d love you to try stamping anything on my neck, I could use a good laugh…

    1. Correct. The PC-Engine CD-ROM drive was released in late 1988 in Japan. The Sega-CD was released in late 1991 in Japan. In fact the TurboDuo which was the intergrated version of the main console and CD-ROM drive came out before the Sega-CD attachment.

          1. Set guns to ban mode – But captain they they will never oscillate with all this feed back. I’ it’s true captain, the ‘Q’ factor – she can’t take any more feedback.

    1. I imagine these days it’d actually be pretty easy – though getting quality graphics out may not be. But essentially riffing off things like the Arduboy with the games being stored on cart format external cards.

      On the other hand, maybe people have done enough of the work for you to start down the path of quality output with FPGAs by emulating other chips on them directly.

  6. The photo of the “Tower of Power” is nonsense.

    Besides plugging in the Master System power base into the 32X (never met anyone that felt the need to do this), the Cleaning System is plugged in above it. Do I need to state what is wrong with that? Then the two Sonic & Knuckles games above the Game Genie.

    As a humorous chide against the Genesis design choices, I get it. But as a reference image in a tech article? C’mon….

    Yeah, this is about the fanboy crap. This is about presenting an article on a t3ch oriented site with respect to either side. If you can’t do that, regardless of which side is deemed “better”, then the article is worthless.

  7. Hey Brian, I hate to point it out, but the Sega Nomad wins this argument for Sega. :P A decent quality handheld worth having (even if the screens did ghost a bit too much). Oh, and the prices weren’t kept at artificially insane rates. ;)

    1. Nomad also wins points for being the only portable made (homebrew portabalized consoles don’t count here) that used the same cartridges as the console version. Even better was its capability to be used like a console by connecting it to a TV and second controller.

      The only others that come close are the GameBoy addons for the SNES and GameCube. But those went the opposite way from Nomad, plugging portable games into a console.

      Did any Cube games other than Pac Man exploit the ability to use a GB Advance for a fifth player?

  8. One minor correction. It is stated that:
    “In the 68000, each instruction requires at least eight clock cycles to complete, whereas the 65C816 – like it’s younger 6502 brother – could execute an instruction every two or three clock cycles.”.

    This isn’t quite correct. The 68000 had many 4 cycle instructions also. For example 32-bit register move “MOVE.L D0,D1” (I don’t believe 65816 could do 32-bits in one instruction) or 16-bit register addition “ADDQ.W #1,D0” are 4 cycles (see http://oldwww.nvg.ntnu.no/amiga/MC680x0_Sections/mc68000timing.HTML ).

    I suspect which is faster between an ~8 Mhz 68000 or a ~4 Mhz 65816 CPU depends on the task at hand (on a level playing field – not SNES vs Genesis systems).

    1. There is a lot of errors, I reported some of them on twitter in reply to the article post.
      This is the kind of bad article that made people believe that the NeoGeo have an hardward zoom. It has no source so it can’t be trusted.
      And unfortunately this article will say on the internet and people will cite it as source elsewhere.

    2. Yes, I noticed that. Clock for clock, the 68000 can compete with a 65816 for several reasons:

      1. The basic instruction cycle requires 4 clocks, not 8; and this includes all word-length register to register arithmetic and logic; frequent immediate cases (such as moveq #n,d0) and 32-bit moves. Even with shifts the 68K has the edge, since it manages multi-bit shifts at 2 cycles per bit (so a 7.3MHz 68K is twice as fast as a 3.6 MHz 65816).

      2. The 68000 has 16 x 32-bit registers and it’s instruction set is double-operand which makes it very versatile. It’s the bandwidth of data that can be pumped through the 68K that makes a huge difference to its performance. For example, the 68K as enough registers for subroutines to be entirely register based whereas the 65816 would need lots of LDA/Operate/STA sequences.

      3. The 68000 can move data around much faster than a 65816 using its movem.l instruction. Movem.l can move up to 12 x 32-bits from source to destination using just (8 cycles * 12 + 8)*2 = 216c for 48 bytes, or roughly 4.5 cycles per byte. A 65816 can only manage 7 cycles per byte.

      4. The 68000 can handle 32-bit arithmetic several times faster than a 65816.

      5. The 68000 is far easier to program than a 65816, it’s easier to squeeze performance from it.

  9. The Genesis / Megadrive block diagram has some glaring errors in it that the 68k address bus is 23 bits wide (word access, so really 24 bit or 16MB) and the z80 address bus is 16-bits wide and was mapped into the 68k’s address space.

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