With an Amiga A500, Action Replay cartridge (v1.5 or later) and memory expansion, it was possible to save a copy of the state of memory, much like a save state in an emulator. Were there any other systems that allowed save states to memory in a physical hardware / non-emulator environment?

  • Cross-post gaming.stackexchange.com/q/387877
    – pipe
    Jul 14, 2021 at 12:07
  • Not really an answer, but tangential: most of the early models of the Macintosh lack an MMU of any variety, and expose a whole load of UI state for direct memory access. So when they added multitasking they achieved that by copying the exposed area in and out upon a task swap. I hope this is a Macintosh-specific comment; you've got to have really boxed yourself into a memory map corner to have to start physically moving bytes like that. Both Win16 and the Amiga, amongst other potenitally-non-MMU platforms, had better foresight. I've no idea about MultiTOS.
    – Tommy
    Jul 15, 2021 at 18:15
  • Interesting to know! Hopefully Apple has remedied that by now (but I kid :-D)
    – Sam
    Jul 19, 2021 at 8:09
  • @Tommy: The first switcher for the Mac may have worked like that, but MultiFinder simply gave different programs different address ranges, and relied upon programs not to step on each others' screen displays.
    – supercat
    Jul 19, 2021 at 15:46
  • 1
    @Tommy: Ah, okay. The original switcher kept a copy of the screen bitmap, which is what I'd thought you were talking about. Toobox globals represent an interesting situation, since I think they were deliberately shared between applications and desk accessories. I wonder if the use of separate A4 and A5 worlds was designed to allow for the notion of toolbox globals being in the A5 "world", but Apple then decided that having toolbox globals based on A5 would be problematic? Otherwise I don't really see why desk accessories couldn't simply switch A5 worlds on entry/exit.
    – supercat
    Jul 19, 2021 at 17:50

5 Answers 5


For the Spectrum, the Microdriver (by Mirage) and the Multiface (by Romantic Robot) had the ability to save the state of memory, to cassette, Microdrive or the Spectrum +3's floppy drive. This state file could then be reloaded.

Later versions of the Microdriver also had the ability to do an uncompressed dump of memory, which was not intended to be reloaded. This was used as the basis for the .SNA file format used by early Spectrum emulators.

  • Thanks but I should have clarified - I meant saving to memory. I am familiar with the old freezer cartridges for the C64 though I didn't know about the Spectrum options.
    – Sam
    Jul 14, 2021 at 11:13
  • 2
    The hardware of a 128k Multiface would have been able to save and restore the state of a 48k game to the extra memory of a 128k Spectrum, but as far as I'm aware the stock firmware never allowed this. The Multiface can load third-party programs that extend its functionality, so it should be possible to write one to give it that capability.
    – john_e
    Jul 14, 2021 at 12:09

ZX Spectrum compatible Didaktik Kompakt had the ability built in - pressing CAPS SHIFT, left arrow and right arrow together saved current state to the floppy (it used a few bytes on the stack, so it could fail sometimes).

  • heh I totaly forgot that Kompakt did not have the Snapshot button like D40/D80 did...
    – Spektre
    Sep 22, 2022 at 9:44

Yes, two examples of these are the Final Cartridge and the KCS Power cartrdige for the Commodore 64. Both allowed the C64 to be "frozen" upon pressing a button on the cartridge and then via a menu the state of the system could be saved to either tape or disk. These states could then at some later point be re-loaded into the system and the C64 would then continue running from the original point of freezing.


There existed at least two such devices for the Super Nintendo:

The NakiTek Game Saver and Game Saver+.

I haven't seen a picture of the base version but the plus version is a bulky Super Nintendo cartridge with a slot on the back to plug the actual game cartridge into.

The difference between the two is that the plus version supports using AC power or AA batteries to retain the saved data after you power the SNES off and, according to this speedrun.com thread, improves compatibility with games like Star Fox.

(AC power is handled by plugging the SNES power supply into the Game Saver and then plugging its output lead into the SNES.)

Also according to that thread, compatibility varies and, because of the architecture of the SNES, you're likely to get audio glitches on restoring saves.

Clint from Lazy Game Reviews did an oddware episode about it.

There's also the Game Action Replay for the NES which is more or less the same idea, earlier and by a different company, and with a manual instructing you to remove part of your NES to get it to fit.

I've heard passing mentions of the existence of a similar device for the Gameboy, but I haven't had time to research that.

  • I missed the clarifying comment on john_e's answer about not wanting examples of freezer cartridges. Sorry about that.
    – ssokolow
    Jul 15, 2021 at 17:44
  • No that's really interesting so thanks! To clarify on my clarification, I only meant I didn't want examples of freezer cartridges that only save to floppy disk or tape (with C64 there was no hard disk available, no memory in the cartridge itself to use and not really expansion of the memory of the C64 itself to have space to save into) so this is exactly the kind of thing that I'm interested in.
    – Sam
    Jul 19, 2021 at 8:03
  • Also your LGR Oddware mention reminds me of another really cool bit of hardware, which I'll add below.
    – Sam
    Jul 19, 2021 at 8:04

I remember now seeing an LGR Oddware video a few months back about an ISA card for MS-DOS PCs that allowed you to write save states. I think he demoed it on Crystal Caves but I don't recall what the product was called (probably another Datel product). I also can't remember if it saved to memory or hard disk... will try and find the video for more details.

  • 1
    I'm almost certain you're thinking of his DOS PC Action Replay video... which is a Datel product... and the cheat code finder part reminds me that I need to tidy up and upload to the Internet Archive a bunch of similar but software-only tools for Windows 95 that I downloaded from Tucows back in the day.
    – ssokolow
    Jul 19, 2021 at 8:43
  • ...a device which I'd forgotten could do save states.
    – ssokolow
    Jul 19, 2021 at 8:51
  • Yes that's the one! Love these videos. Kudos for the uploads - may take one for a spin on my Windows 98 setup!
    – Sam
    Jul 19, 2021 at 8:57
  • Glad to hear it. When they're ready, they'll join the stuff already here. I'll try to at least get my favourite uploaded tonight. (or, if someone else already has, favourited for easier discovery.)
    – ssokolow
    Jul 20, 2021 at 1:44
  • Correction. It looks like it won't be going up because some fast-fingered Internet Archive admin thinks a DOS "abandonware" game cheater like Game Wizard is OK, but a freeware Win9x version of the same concept merits a takedown within seconds and they have no explanations or appeals process I'm aware of. (It was briefly up here.) Reminds me of when they took down an official update patch to Claw that I posted for no apparent reason in the wake of the company's FTP site being gone.
    – ssokolow
    Jul 20, 2021 at 7:36

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