This is an early Street Fighter Alpha 2 / Street Fighter Zero 2 (ストリートファイターZERO 2) prototype, notable due to the fact is does not yet use the special chip and is very early in development. There were several auctions sold by safestuff1 and I bought 2 copies and decided not to buy any more after they were identical and board images were not posted and showed more final character select screens. The date on the first auction has the EEPROMs labeled with the date 6/11, while the date from the other board is 9/15.

HELP WANTED: There are several items I know I will never get to, if you can help with this game or any other with any of the following items, [please contribute on GitHub! Think of this as more of a living wiki (without spam) and contribute in any way that you can. Feel free to reach out to me on Twitter if you need help or want to contribute but aren't sure where to start.

  • Check music against the retail version
  • Check sprites against the retail version
  • Check character move set against retail version
  • Animated GIF to compare


Starting with the title screen, it actually looks better in the prototype and now squished like in the final, a larger and nice typeface for Push Start Button!! and slightly different, less detailed background:

Title - Prototype
Title - Final
2-Up Swipe Onion Skin

Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot Screenshot

Characters & Sprites

This section is thanks to Kiddo Cabbusses / サテラビュー好きの外人さん. I don't know if I got this well in this image (below) but the short of it is; Zangief's stance has more frames of animation in the prototype compared to the final, and by golly it looks a LOT better for it. The final game looks jank in comparison. His stance is the only thing in the prototype, he's otherwise nothing - not even able to attack or get hurt like Ken who is also buggy.


Chun-Li and Dhalsim are actually SURPRISINGLY close to completion. They have some missing graphical effects (Chun-Li's Kikoushou, Dhalsim's Yoga Fire/Flame/Breath/Inferno) and sometimes crash the game. But every now and then you can play through a whole match with them. They may had been intended to be playable by the time this was put out, but the few missing things got in the way. Ken is buggy. Rolento has a stance like Zangief and otherwise does nothing. The buggy Nash-Akuma is crash-prone.

On that note, trivial commentary on the development from what I can perceive: From the characters ready to demo and the ones close to being ready to being demoed, we have 4 SF2 vets, an Alpha 1 character (Charlie) that's basically a reskin of a SF2 vet, and the only "new" character introduced in Alpha 2. Likewise, of the incomplete characters, the ones furthest in are SF2 vets and a character whose first SF appearance is Alpha 2. This gives me an impression that characters were intentionally prioritized - I'm assuming likely in case space issues required them to outright cut someone.

If you win a round with Ken in the SFZ2 proto it will crash. Also it looks like for some reason Ken has programming that's meant to be for Akuma's Teleport move. If you do quarter-circle back + punch he'll move towards the other player at the same speed as the teleport, but he can' phase through and there's no graphical effects.

As reported by Josh Smith, Sakura has all three of her jump kick animations from the arcade version in this prototype. The release version removes the animation from the medium kick and replaces it with the weak kick animation.


The stage layouts are different than the final version, some drastically different.

Adon Stage - Prototype
Adon Stage - Final
2-Up Swipe Onion Skin
Dan Stage - Prototype
Dan Stage - Final
2-Up Swipe Onion Skin
Gouki / Akuma Stage - Prototype
Gouki / Akuma Stage - Final
2-Up Swipe Onion Skin
Ryu Stage - Prototype
Ryu Stage - Final
2-Up Swipe Onion Skin
Vega / Bison Stage - Prototype
Vega / Bison Stage - Final
2-Up Swipe Onion Skin
Zangeif Stage - Prototype
Zangeif Stage - Final
2-Up Swipe Onion Skin

Player Portraits

Portraits have small to noticeable alterations, and there are more complete portraits than stages. Ryu, Chun Li and Sakura have the most changes.

Vega / Bison Portraits - Prototype
Vega / Bison Portraits - Final
2-Up Swipe Onion Skin
Charlie Portraits - Prototype
Charlie Portraits - Final
2-Up Swipe Onion Skin
Chun Li Portraits - Prototype
Chun Li Portraits - Final
2-Up Swipe Onion Skin
Dhalsim Portraits - Prototype
Dhalsim Portraits - Final
2-Up Swipe Onion Skin
Ken Portraits - Prototype
Ken Portraits - Final
2-Up Swipe Onion Skin
Rolento Portraits - Prototype
Rolento Portraits - Final
2-Up Swipe Onion Skin
Ryu Portraits - Prototype
Ryu Portraits - Final
2-Up Swipe Onion Skin
Sakura Portraits - Prototype
Sakura Portraits - Final
2-Up Swipe Onion Skin
Zangeif Portraits - Prototype
Zangeif Portraits - Final
2-Up Swipe Onion Skin

Hacking & How-To Explore

All of this is with the most amazing thanks to Revenant for literally making all this extraction possible. Below you will find notes on how to explore the various functions in the game and possibly find more! These codes are included in the download below as a CHT file.

Notes: Each character slot on the select screen has 4 bytes that determine which slot to move to when pressing a direction on the D-pad, and some of the unfinished characters are "still there", sort of, in that they will skip over other adjacent characters if you are actually able to select them- if that makes any sense. So it seems like more characters may have been planned to/close to actually being included on the select screen.

Sprite Debug Controls:
  Controller 1:
    Y: Step Pose Frame
    X: Animate Pose Infinite
    B: Reset Pose
    A: Animate Pose to End
    Start: Change Table
  Controller 2:
    L: Previous Palette
    R: Next Palette
    X: Previous Pose
    Y: Hold to orient sprite / hitbox
    B: Next Pose
    A: Hold to orient sprite / hitbox
    Start: Toggle Hit Boxes

There is a dummied 6th option on the stage select to play on Zangief's stage, but it doesn't have background animation. All characters' theme music seems to be intact.

Pro Action Replay Codes:
  9FA6C1xx - char select music modifier

  C0367005 + C0368C06 = add zangief stage to menu
  (invisible + displays glitched banner but otherwise works)

  DFA7EFxx - ryu stage modifier
      00 = ryu
      02 = akuma
      05 = adon
      0a = bison
      0c = dan
      10 = zangief
      other stages up through 10 have music but no background

  C031A4xx - replace ryu with character on menu
      00 - ryu
      01 - ken
      03 - charlie
      04 - chun li
      0a - bison
      0d - sakura
      0e - rolento
      0f - dhalsim
      10 - zangief
      (values are actually the same as stage values above, but usable ones differ)

      other characters use wrong sprites/portrait, but possibly correct palette?
      (i.e. 02 is akuma, and appears to still use his palette)
      not sure how any of the missing characters actually behave if selected

  7E0492 - p1 char ingame
  7E0712 - p2 char ingame
  7E00C7 = 08 -> character debug

  C0201608 - enable during match (uses current p1 character)

  7E00C4 = 04 -> stage debug

  C01DF504 - enable on boot
      for some reason, loads stage number from address normally used for p1 input
      so holding down R button (value $10) goes to zangief stage.
      only values of $10, $20, $30 etc. can be entered this way, so most stages can't be
      but if button X ($40) is held down it will specifically load $05 (adon stage) instead

  C03B5800 + C03B5Axx - debug stage modifier (see above for values)

ROM Information

The ROM information (below) also has a different internal title, the retail title is STREET FIGHTER ALPHA2:

---------------------Internal ROM Info----------------------
       File: sf2z.sfc
       Name: Super Street Fighter2    Company: Capcom
     Header: None                        Bank: HiROM
Interleaved: None                        SRAM: 0 Kb
       Type: Normal                       ROM: 32 Mb
    Country: Japan                      Video: NTSC
  ROM Speed: 120ns (FastROM)         Revision: 1.0
   Checksum: Bad 0xE210 != 0x0000   Game Code:
      CRC32: 349D8084
        MD5: 1BDF3D1524794B36745FDE718E2BA646
      SHA-1: CC4CC2F858D25280FD984F5A9F8164DC120860EB

Board / Cartridge Images

Images from the auction itself until I have time to update them.

Auction 1 Cart Auction 2 Cart Back Auction 2 Cart Front

Playthrough Video

A gameplay video play through played by Kiddo Cabbusses | サテラビュー好きの外人さん:


Download Street Fighter 2 Zero (Japan) (Prototype)