Post subject: Ultima 7 + Serpent Isle
marzojr
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Joined: 9/29/2008
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Location: 🇫🇷 France
So, I have been thinking of TASing these games. Which is fitting, since I am probably the person who knows most about it on the planet. But right off the bat, I found a couple issues which would require a ruling of some sort. As is well know and dreaded by x86 emulator developers, Ultima 7 and Serpent Isle both use a custom memory manager, Voodoo, which puts the machine in unreal mode. That, by itself, is probably not a problem (jpc-rr supports this mode). Moreover, both games are memory hogs as far as conventional memory goes. This is not much of a problem either, as one can comfortably get them to fit by moving stuff to upper memory (although this is far easier to do nowadays with emulators than it ever was in real machines, except for DOS 7). The real issue is that the way the games detect available conventional memory (and also probably the way they allocate it) is completely incompatible with FreeDOS. This is a known problem by FreeDOS devs, who just don't care enough about a couple of oddball games to make an exception to their memory manager. So there would be three routes for this: (1) use MS-DOS instead; (2) bypass the memory check; (3) hack the game to be compatible with FreeDOS. I really don't want to do (3) (and only one person has ever done it, for Windows compatibility). (2) can be done either by hacking intro.exe to bypass the check or by bypassing intro.exe/mainmemu.exe and running "u7.exe c150 p" directly. The latter eventually fails with a GPF in instruction FF/7 (don't know if it fails because of jpc-rr or because of FreeDOS). I think it is highly likely that the former will also fail in the same way. So there remains (1), with all of the legal issues. I have been able to run U7 with a (slightly tweaked) DOS 6.22 disk image. How acceptable would this be for submitting a movie? The only changes from stock DOS 6.22 is autoexec.bat and config.sys.
Marzo Junior
marzojr
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Experienced player (749)
Joined: 9/29/2008
Posts: 964
Location: 🇫🇷 France
Well, MS-DOS also fails a bit further on with GP 4 in instruction FE/7. So it seems like Ultima 7 remains the base of emulator developers. So I guess there will be no TAS for it after all, until they either fix it or DOSBox TASing becomes a reality.
Marzo Junior
Patashu
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Joined: 10/2/2005
Posts: 4017
Sorry to hear about it! Hopefully DOS emulation will improve in the future, as this is definitely a game worth TASing.
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