VOGONS


First post, by Sephiroth

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I've finally began updating my front-end to work with 0.73 but have a few questions that I cannot seem to find answered elsewhere. The big one is the new "cputype" setting in the configuration file. Does it affect emulated instructions (for example, a 386 won't emulate MMX) or is there something else to it? Also, what are the different settings for? I note that there is a "486_slow", but no "486". I'd just like some detail as to what these options do in 0.73 so I can set them up in my front-end properly.

Oh and I like the support for some of the awesome video cards of the DOS days like the Tseng ET4000.

486 Launcher v2.0 is now under development!

Reply 1 of 9, by DosFreak

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Probably shouldn't even be available in a frontend unless it was under a Troubleshooting/Advanced section or somesuch (otherwise users would wrongly use them or recommend it like other things that are wrongly used because they are "better")

CPUTYPE settings and CYCLES settings.

Same thing stands for the extra video cards. They are only needed for games that need them and shouldn't be used/available otherwise.

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Reply 2 of 9, by h-a-l-9000

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# auto
- 386 page access level calculation
- 486DX CPUID
- BSWAP, CMPXCHG, XADD, INVD, WBINVD
- 486 specific CR register behaviour
- loose page privilege check for more speed

# 386
- 386 page access level calculation
- loose page privilege check for more speed

# 386_slow
- 386 page access level calculation
- tight page privilege check (can slow down to a crawl depending on the game)

# 486_slow
- 486+ page access level calculation
- 486DX CPUID
- BSWAP, CMPXCHG, XADD, INVD, WBINVD
- 486 specific CR register behaviour
- tight page privilege check

# pentium_slow
- 486+ page access level calculation
- Pentium CPUID
- BSWAP, CMPXCHG, XADD, INVD, WBINVD
- RDTSC
- Pentium specific CR register behaviour
- tight page privilege check

# 386_prefetch
- 386 page access level calculation
- loose page privilege check for more speed
- prefetch queue emulation (normal core only)

No guarantee on correctness.

1+1=10

Reply 3 of 9, by Sephiroth

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Thanks for the replies. I asked because my front-end already has a CPU-type for each game so a user can sort by CPU required. I actually own the boxes to all my old DOS games and have full specs on them and thought that it would be a good way to organize them if the user so desired.

My next question however, is why I wouldn't select "386" for games that ran on real 386 processors or earlier? For example, Railroad Tycoon required an 8086 and 640k RAM (looking at the box now). What harm would using the 386 type do? I mean it will run on a Pentium, but wouldn't selecting 386 require less real CPU power to emulate than say the Pentium option?

486 Launcher v2.0 is now under development!

Reply 4 of 9, by h-a-l-9000

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auto is tested the most so leave it at that setting unless another value is required for the game. That way the Pentium question isn't even relevant.

1+1=10

Reply 5 of 9, by Sephiroth

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I'll take your word for it, it just doesn't make sense to me personally to use auto (which appears to be a combination of 386 and 486 stuff) if all you need to run an archaic game like RRT is the 386 stuff. New game configurations always default to "auto", but the user can change it if he or she so desires. At that point it's on them!

486 Launcher v2.0 is now under development!

Reply 6 of 9, by h-a-l-9000

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The additional features auto provides over 386 shouldn't produce noticeable slowdown.

1+1=10

Reply 7 of 9, by Sephiroth

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Alright, well it is the default and I am already coding in the other changes, such as no longer being able to do "cycles=5000" and instead needing "cycles=fixed 5000". I'm also moving the mouse configuration from a global option to a per-game option so different games can have different sensitivities and such. I'll ask here if I have any other questions about 0.73. Thanks for the help, Hal and Freak.

486 Launcher v2.0 is now under development!

Reply 8 of 9, by Sephiroth

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Quick question. For old games that only require VGA, such as Doom or games for an 8086, would there be any harm in using the "vgaonly" option? Also, for games that use VESA, such as Blood, Shadow Warrior, or others, wouldn't I need to select one of the two VESA options to take advantage of the game's capabilities?

486 Launcher v2.0 is now under development!

Reply 9 of 9, by wd

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As everything else, leave the default because it's the default for a reason.
vgaonly may not use standard resolutions, has possibly-slow features etc.
VESA games run best with the default s3 selection as well.