Where can I get the code for the prefetch queue emulating CPU? I'd like to roll it into a more modern version of DosBox.

Just out of curiosity, how would using the prefetch queue in this way serve to copy-protect the game? It seems as though it can be copied.

Yep that latest build works on my Athlon. Only problem is apparently it's a really ancient build and the timing is all off and the graphics are screwy and stuff.

Tried the dosbox prefetch version on a P4 celeron, and it worked. Seems like somehow there were SSE2 instructions in it or something. Jetfighter worked perfectly w/ the prefetch core and did the normal errors with the normal core. Much appreciated. If possible, at your convenience, please re-compile …

In the mean time, can you give me the details of how you got that prefetch build working, i.e. what CPU, OS, sdl dll files, etc.? Also, can you post the dosbox.conf file that it worked with? Lastly, if anyone else has a prefetch queue emulating build, please post.

If you could do that it would be much appreciated. I've wanted to play this game ever since I dumped my 386, and have been curious how it could not work on a supposedly binary-compatible CPU or even an emulator. I guess Intel and AMD's claims that their modern X86 CPUs are 100% binary compatible …

I guess I wasn't clear before, so let me restate: I can't even get this thing to run. It gives me an illegal op before it gets to a command prompt. I also tried it on my laptop, same error, so it's not just my computer. If this has any strange CPU-specific optimizations, I need a version that is …

How do I get this working? It keeps performing illegal ops when I copy sdl.dll and sdl_net.dll from my default dosbox installation. I think that's probably the problem, but where do I get the correct versions of these files?

I believe there were two iterations of this game: the original and the Memorex re-release. I have the Memorex re-release. Also, I looked at jf.exe in a hex editor, and almost nothing in it is in any way human-readable and there was no evidence, from what I could see, of copy protection.

Just as a sidenote: you mention copy protection. The manual for this game explicitly states that it is NOT copy-protected. Also, as far as speed, for anything ancient enough to not be able to run on a 486 speed isn't much of an issue. Therefore, at least from that perspective it makes sense to me to …

I have come across an interesting fact concerning the original Jetfighter game. Apparently, it does not even run on newer CPUs in pure DOS. I remember seeing, back in the 386 days, a warning in the instruction manual for this game that it may not work on some 486DX2 CPUs. It worked fine, of course, …