What could cause a 17-year-old game to crash on a modern Windows 7?!

Hi. I was playing "Jazz Jackrabbit 2" on my computer, and it crashed with some kind of application error several times in a couple of hours. I've attached a screenshot of the error window(s). Also, for next time, how do I place an image inline in a post?

One more thing. Can someone give me a little information or links to information about what the Assembly Language registers pertain to in the Application Error windows of the screenshot? I've just started teaching myself Assembly Language, so I'm curious :)

Jazz Jackrabbit 2 appears to be a DOS game (16-bit).

You need a DOS emulator like DOSBox to run DOS games. Here is a how-to for that with DOSBox. That will basically be a virtual machine (drive) emulating the functions of an old DOS/16-bit computer. You will have to assign it a drive letter during initial setup (very similar to programs for ISO mounting, e.g. Daemontools. You will have to ‘mount’ and ‘unmount’ games in DOSBox, depending on which one you want to play in it).

And for installing DOS games from a disk, see this. If you don't install them like that you will most likely still get the same errors you’ve received already when trying to launch/play them (which is the game inappropriately accessing memory). Generally, DOS games will install without an emulator, but not play issue or error free without one.

Though DOS emulators will still not run every DOS game. Its hit or miss. Here's a compatibility list for DOSBox.

MagusMagnus said:

Jazz Jackrabbit 2 appears to be a DOS game (16-bit).

Jazz Jackrabbit 2 was released in 1998. I thought that games made for Windows 95 and after no longer had DOS compatibility issues. Is that not accurate?

MagusMagnus said:

You need a DOS emulator like DOSBox to run DOS games.

Awe yes. I'm curious about that, because it sounds like you're saying that DOS games emulate directly in DOSBox. In my quest to find a way to play the original Jazz Jackrabbit (from 1994) on my computer last week, I ended up using this approach: D-Fend Reloaded: Overview

Once I finished setting up D-Fend Reloaded, DOSBox was not posing as the actual emulator, but as just another required inclusion for Jazz Jackrabbit to be playable inside of D-Fend Reloaded (see my attached screenshot). D-Fend Reloaded seems to work, but I want to use whatever tool that makes it the easiest to mount DOS game ISOs. Do you think I'd be better off using DOSBox as the emulator itself?

Ah, I see the problem now. Windows 95, 98 and ME/2000 are DOS 32-bit. However, they were also compatible with the older 16-bit DOS. I have no idea which one this game is (can't seem to find that information), but if it's the latter... unfortunately, see this. DOSBox does not run 32-bit DOS games and there is currently no emulator available for it either. Apparently, its a real crap-shoot as far as actually getting those games to run on current systems at all (I'd have to say, particularly on a 64-bit system). They either just work, or they just don't. I tried to see if I could find you a patch or source port, but I wasn't successful (even if I had, I'm uncertain if it would have been entirely legal).

Although, all 32-bit (but not 64-bit) versions of NT Windows (including XP, Vista, 7, 8/8.1) have NTVDM, or which is a native Virtual DOS emulator... but I'm not sure if that is particularly inclusive of the aforementioned DOS variety as well (only 2000 and XP had nearly full DOS support through NTVDM - so I'd think they'd be your best shot with this, outside of actual 95, 98 or ME). And that doesn't really help you on x64. I guess if you have a 32-bit version of any one of those and you have the free system resources to run it in a VM, you can attempt that. But there's no guarantee it would run any better than it does now.


D-Fend is just a graphical environment for DOSBox (DOSBox is still handling all the emulation). Just makes it a little prettier and perhaps a bit less complicated, though I don’t know about that personally as I haven’t used it.

According to wikipedia, Jazz Jackrabbit 2 is NOT a DOS game, it's already is a native Windows game, do DosBox cannot help in any way. In contrast Jazz Jackrabbit 1 is a DOS game, but certainly not what the OP was asking here at least.
The screenshots also confirm this, as the Visual Studio JIT debugger cannot be attached to DOS programs, in addition to the "application error" windows showing CPU registers, cleanly indicating that we're speaking about a 32 bits program there.

As for the problem itself, have you tried the compatibility modes? Maybe XP or even Win95/98 compatibilities help in some way. There is also a chance that the game itself has a bug that really makes it crash regardless of the OS.

MagusMagnus said:

Ah, I see the problem now. Windows 95, 98 and ME/2000 are DOS 32-bit. However, they were also compatible with the older 16-bit DOS. I have no idea which one this game is (can't seem to find that information), but if it's the latter... unfortunately, see this. DOSBox does not run 32-bit DOS games and there is currently no emulator available for it either.

There is no thing as 32 bits DOS, it is a 16 bits OS and all programs ran under it are 16 bits. Even the DOS included in Win95/98/ME is also a 16 bits one, that supports the 32 bits Windows on top of it. DOS extenders were often used to enable running 32 bits code on DOS and make use of newer 32 bits processors but in any case that's bootstrapped by 16 bits code. And DosBox can for sure run those programs.
But that's not the OP case anyway.

TimeAssassin said:

One more thing. Can someone give me a little information or links to information about what the Assembly Language registers pertain to in the Application Error windows of the screenshot? I've just started teaching myself Assembly Language, so I'm curious :)

The values shown there are those of the internal state of the game at the point where it crashed. I would say that there is little meaning in those values unless you're the developer himself so that you can follow how it reached that state. That or unless you really want to understand what it does which is a much difficult matter. What information is what you want exactly?
To begin with, at least for some basic general information about the uses of those register the Wikipedia article on x86 serves as a good starting point.

Hi there

It's quite easy - old games probably used back door things like DMA (direct Memory access) - of course RAM memory addresses and things like where system (OS) control blocks are held have changed significantly so using direct memory accesses with direct access to the hardware could easily cause a system defect and a crash. The OS in theory should protect against this sort of thing happening - however sometimes if the game reacts directly with the HARDWARE which then in its code does some strange things then the OS can't always intercept these "Non Standard" calls. DMA etc was used quite frequently back in early DOS and Windows days to avoid the overhead of using the OS --remember also PC's had very limited hardware and RAM compared with today.

I'm not a coder so I can't help you in fixing the issue - I only have "theoretical" knowledge but that's how it works.

You *Might* be able to run the game successfully in a Windows VM - go back to say Windows 95 or 98 - there are generic keys around as these OS'es are considered as "Abandonware" by Ms.

You only need a key - no activation is needed on these old OS'es.

For Windows 98 use : VP9VV-VJW7Q-MHY6W-JK47R-M2KGJ


Cheers
jimbo

Microsoft has published the rules which developers must follow if applications are to run on future operating systems. Many well behaved applications that are 17 and more years old run without problems even on Windows 10. Unfortunately games are notorious for being poorly behaved. Rules are often seen as only guidelines to be bent or even broken if you can get away with it. Few game developers care much for compatibility with future systems.