Sorry about the very late reply, but I only just came across your post when I was looking for information 😀

I have been trying to get this game to work for ages, but I'm just not having any luck. It always fails in the place you mentioned no matter what you do to get it going. I've heard that JF2 uses all of the video memory, so it's possible that Dosbox doesn't yet emulate enough of this for the game to work. But that's just a guess, I have no idea why it doesn't work.

Not exactly. The game is using unimplemented opcode. If you can compile DOSBox yourself, there is a patch on SourceForge that fixes this problem. Otherwise, just wait a little and some unofficial (or "official") build will pick that patch.

Thanks for implementing that patch, I thought this was one game I'd never be able to get working 😀

Unfortunately, I still haven't!!! 😉 I downloaded the patch it and applied it to the latest CVS source code, and then built it. The build was fine, ran perfectly, but behaves exactly the same as before.

Does your patch only work on the Windows copy of Dosbox? I'm no expert, but I couldn't see any signs of it in the diff....

Thanks

Make sure you are not using full core -- the patch only works in normal, dynamic, and simple cores.

I know, I read your instructions before I attempted to apply the patch.

I tried both simple and normal cores and still the same thing happened as with 0.65. I then tried different versions of the game in case one worked and the others didn't. I had varying results, but none of them made it to the flight screen. One of the following happened in all cases.

1: The same thing as with 0.65. The game froze while trying to enter flight.
2: The game exited with an error. I saw these two: "Exit to error: Illegal GRP4 Call 5", "Exit to error: CPU:GRP5:Illegal Call 7".
3: The game simply returned to the main menu without any warning.

I've seen 1 and 2 before, but 3 is new to me. So your thoughts on the matter might be on the right track anyway.

I have some idea why number 3 might be happening. I tried the patch with Jetfighter I too and I saw error 2 as well as the game simply dropping to the command-line. I suspect that's what might be happening with number 3 in Jetfighter II as well.

The patch would not help the original Jetfighter. For me, the patch works with both known good version of JF2 from "Select Pac Jet Set" release and with some odd version that was just floating around the web. Many files in those two versions are identical but there were some differences. I never saw the problem 2. What is that "main menu" you refer to in 3? Do you use some kind of loader? In that case, try running jf2.exe directly and see if there is any difference.
I don't know if this is related but try playing with sound settings in dosbox.conf -- mine currently has sb16/220/5/1/5 and no gus. Also, make absolutely sure that the patch actually worked -- the only important change is a few new lines in file src/core_normal/prefix_0f.h.

EDIT: Just noticed that ykhwong has posted another build on his site and that one got this patch. Verified -- my version of the game runs fine in that build.

I've heard that there are two distinct versions of Jetfighter II, one that works with memory managers and one that doesn't. I also believe that at some stage, Jetfighter II was patched to run on new PC's, so it's possible there are three different versions out there. Maybe one or two of these work with your patch and the other(s) don't. I'll track down all the versions of the game I have and see if I can get any of them to work. I'll also try all the other suggestions you made and get back to you on that 😀

By the way, I meant the game menu itself where you select your flight mode 😀 I have been running jf2.exe directly.

Thanks again

A Version 1.05 Patch for Jetfighter 2 is available at

http://www.patches-scrolls.de/

I already have an original version, a 1.05 version and the patch too (which I can use to patch the original of course) and haven't been able to get any of them to work 😀

I can confirm that ykhwong's build didn't make any difference with any of the copies I have here (four in fact). My built copy from source did also include the patch correctly. The sound settings made no difference either. Actually, I just realised that ykhwong hasn't updated his Linux build in a while anyway, so that test was pretty meaningless.

I'm at a bit of a loss at this stage. I think the best thing to do now is to try the Windows version of the ykhwong build and see if that makes any difference.

I finally found out what was going on. I'm afraid I must claim a bout of stupidity interfered with my common sense 😀

Ykhwong's Windows build worked with three of my JF2 versions. That made me wonder about my build, particularly since the patch doesn't seem to contain any OS dependent code. I suddenly realised that when I applied your patch, I noticed it referenced two source directories, dosbox-cvs and dosbox-quickpatch. After copying the latest cvs to those two directories, I then patched the code and built it. But previously I assumed after viewing the diff that the patched version was dosbox-quickpatch. I just tried to build dosbox-cvs instead and that worked perfectly with JF2. Obviously dosbox-cvs was the one patched and not dosbox-quickpatch 😀

Sorry about missing that before, but at least we've found the problem now 😀

I could submit a Linux build with this patch if somebody wants it. I'm not sure where I'd store it though, any ideas? I suppose I could just attach it here on the forum.

Thanks for your help.

maybe in the future patch like this.
enter your dosbox directory
patch -p1 <patchfile

no problems with which directory...
(if you want to remove the patch
patch -Rp1 <patchfile

Yes, I guess the path information provided made it less than fool-proof for a casual glance, but I guess it's my fault for not looking harder.... 😀

Diff/patch utilities are always somewhat confusing. I had my own fun time before I found the exact set of utilities that worked reliably. My version of diff echoes command line for some reason but patch ignores everything before the first "---" anyway.
Well, looks like you've got Jetfighter II working. The reasons why the original Jetfighter does not run are different and were discussed before (Jetfighter). There is even custom DOSBox build in that thread that works, sort of.

Thanks for that, I saw the thread before when I was searching for Jetfighter II information. It seems that the support for this game has been long-since dropped unfortunately in recent times. I would be nice to have every DOS game working in the future, but if not, I guess Jetfighter II was a much better version of the game than Jetfighter the original. So can't complain too much 😀

Thanks for submitting that patch for JF2 by the way, it's much appreciated.

I've played quite a few rounds of this game with the patch submitted by Vasyl and it seems to work almost flawlessly. The only problem I have is that the sound sometimes cuts off if the engine tone hasn't changed for a while, a particular problem when using afterburners. Changing the tone restores the sound. I'm not quite sure what would cause this problem, but it seems possible that some kind of sound buffer runs out and the sound is dropped. This is using Soundblaster/Adlib emulation.

As for the game itself, I think the patch is very stable and can probably be considered for integrated into the CVS.

Thanks again to everybody for their help

Dunno i added an implementation for the test registers using
dummy variables, so it should be working for quite a while already.

2006-09-17 15:38 c2woody

* include/cpu.h, src/cpu/core_full/op.h,
src/cpu/core_full/optable.h, src/cpu/core_full/support.h,
src/cpu/cpu.cpp, src/cpu/core_normal/prefix_0f.h: add TRx
handling opcodes (fixes JetFighter2, thanks to vasyl)

I would think the patch is already in CVS?!

I didn't look at vasyl's patch, but used my old DRx stuff for the TRx regs
which works nice with this game. vasyl did all the debugging and found
out that the game doesn't rely on the real behaviour of TRx but just uses
it to be sure that it's run on a newer processor or something like that.