Sorry for the dumb question but how do I run FASM in Dosbox? When I use the dos version of fasm it gives me an error that says "error: processor is not able to enter 32-bit real mode"

Thanks

DOSBox doesn't emulate the 32-bit unreal mode correctly, thus the only way to run fasm under DOSBox is to install some DPMI service (like HDPMI32 or CWSDPMI).

BTW, even though this thing doesn't work right, I really love the latest DOSBox - it runs the most of my old DOS stuff perfectly. In fact I fell just like I had my old DOS computer right here, windowed under 64-bit XP. Great thing.

Hi rCX, see here low on page.

Great emulator Tomasz, i love it

Now there is a good reason not to use unreal mode if ever there was one.

Thanks! It works but there is still one problem . I configured dosdox to run "CWSDPMI.exe -p" every time it starts. The first time I use fasm it works but when I use it a 2nd time dosbox freezes. Does anyone know how to fix this?

I fixed it . Thanks for your help!

Just FYI, I like DOSBox a lot too (and use it frequently), but it's quite slow (and I think they say you really need > 1 Ghz just to get 486 speed, meh). DOSEMU is supposedly faster, but I have yet to find a Linux liveCD that has it preinstalled. (At least DOSBox 0.72 is in antiX-M7.2.iso, but it didn't run well at all on their suggested target of P2/128 MB RAM).

would you care to elaborate? it could help others.

Basically what you have to do is run "cwsdpmi.exe -p" before you run FASM. The overly detailed explanation now follows ....

1. Download csdpmi5b.zip from by clicking on the "Binary Distribution Link" here.
2. In the zipped folder under "BIN" you will find "cwsdpmi.exe". Copy "cwsdpmi.exe" to your fasm folder (or wherever you like if you are familiar with DOSBox).
3. Start DOSBox and enter "mount Z C:\blah1\blah2\FASM\" (or something like this).
4. Then enter "cwsdpmi.exe -p" (This starts DPMI. The "-p" cwsdpmi.exe tells the program to stay resident meaning that you only need to use this line once.
5. Then enter "fasm file.asm file.exe"

So basically like this:




If you want to, you can have cwsdpmi run automatically when you start DOSBox...
1. Open "dosbox.conf" It can be found in e.g. "C\blah\dosbox\dosbox.conf"
2. At the end of the file under:

3. Write

4. Save dosbox.conf
5. Run dosbox and use fasm as much as you want.