387 emulator

Posted on 1997-12-15
Last Modified: 2009-12-16
I'm searching for a free 387 emulator tha runs under Windows 3.11.
If You have one, please mail to:

Question by:Gino121597
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Expert Comment

ID: 1017255
Dear Gino,

387 is half a 386DX, as you probably know.

It is - to be exact - a working FP-unit picked from the 'bad'-die-pile in Intels founderies about 5 years ago.

Either your software is able to emulate the missing floating-point-unit, or you should visit one of the second-hand-PC-vendors and replace your 386SX with a 386DX (upgrade-costs about 2 US$)

Everything else does not make sense in your case.



Expert Comment

ID: 1017256
Usually 387 emulators did not perform well both in WIN 3.11 and in DOS. They tend to make your system unstable conflicting with other TSR and so on and are/not are able to work in protected mode. I think it is better to go and buy a few dollars chip (a real 387).

give you the choice to test them.

Expert Comment

ID: 1017257
Adding to the previous comment: look in
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Author Comment

ID: 1017258
Sorry, but this is a hardware solution, and I would prefer a sotfware solution, till my applications are't so intensive fpu users

Expert Comment

ID: 1017259
If you want the software-solution, use it. Parenti recommend an FPU-emulator. But for performance-reasons I would strongly recommend the 2$-upgrade to a 386DX (which "includes" the 387)

Never emulate something that you can have in hardware for the same price. You can expect in the case of the 387, that the performance will be worse than without the emulator.

Expert Comment

ID: 1017260
Yoooh Tabit ...

Where did you get the idea that a 386 contains a copro ???

you're mixing things up a little , 486 dx contains a copro
but not the 386 ... :-)

to much champagne on christmas evening perhaps ... ho ho ho

merry christmas ...

Expert Comment

ID: 1017261
evil ed:

sorry, I missed that. I switched directly from 286 to 486SX to Pentium. But you would certainly agree to the point that to have a hardware 387 for 2 bucks is a much better solution that to slow down the slow 386 with an emulator.


did you try the emulator parenti recommended?

Accepted Solution

parenti earned 50 total points
ID: 1017262
I cannot understand in which sense the SW I proposed you are an HW solutions. May be that some mis-alligment in the chat has been there.

So I only can give you again the pointers to the SW-only solution(s) you can try (you will find a tenth of them for any pointer!)


I want to recall that usually the 387 emulators did not perform well both in WIN 3.11 and in DOS (you must choose). They tend to make your system unstable conflicting with other TSR and so on and are/not are able to work in protected mode.

If you were going to work with it,  I definitively think it could be better to go and buy a few dollars chip (a real 387), but if you are playing you can try.

I think that no more can be said on the matter.

My best regards.

give you the choice to test them. Comment from parenti...Adding to the previous comment: look in 

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