When trying to compile, Fasm shows an error message: out of memory. This didn't happen with previous versions of Fasm though.
I know my PC has very little RAM (only 48 MB) but why Fasm doesn't want to use any virtual memory (on HDD)? It should be possible to use Fasm even when there is no free RAM available. Currently it is possible to compile with ANY other assembler, but not with Fasm.
The memory handling should be improved.

President.

Oh, I forgot to mention that I use the console version of Fasm for DOS/Win32.

I had to change it a little bit in the latest version of fasm, because I've got some complaints about unwanted swap file increase with the previous releases. The main problem that causes it all is that fasm needs the whole block of memory it will use to be allocated before starting the compilation (this is the architectural relict, caused by the fasm's origin - it was originally written for single-task OS without any virtual memory). Currently fasm allocates 50% of physical memory, but it was a mistake, it had to be 75%. Look in the SOURCE/WIN32/SYSTEM.INC file, there is an init_memory routine. In 1.46.9.6 it begins with:

Replace shr edx,1 with shr edx,2 to fix my mistake. If you want, you can also replace mov eax,dword [buffer+12] with mov eax,dword [buffer+28] to use the whole virtual memory size intead of physical memory size as a base for calculation, but I won't do it in the official releases.
It is also possible to make Win32 version of fasm handle out_of_memory error differently - it may increase the memory block an begin compilation once again instead of displaying an error message and exiting, what do you think?

I replaced "shr edx,1" with "shr edx,2" and compiled the Win32 console Fasm with Win32 GUI Fasm. Then I tried to compile something with the modified version of Fasm, but it is still problematic: sometimes it compiles, sometimes exits with the out_of_memory error.
By the way, the GUI version works all the time perfectly. Maybe because there I can set the amount of memory to allocate for compiling. Now maybe adding a command line option to set the memory block size manually (for the console Fasm) could help to correct problems?

President.

It seems you have very small amount of free physical memory - please try the further modification.
Anyway I can also make the console fasm use the .ini file to read the memory settings and environment variables like the GUI version...

Oh, yes! Reading .INI file would be fine!

President.

Please try the 1.47, I've changed it to use half of the existing physical memory - in your case it should be 24 MB, and it shouldn't touch the swap too much I hope.

Yes, thanks, Privalov! Now it works!
But, you could still make something to enable to set the size manually too. For example, half is the default, but even if it is not enough (or is too much), then it should be possible to set an optional command line option for this. For example, to compile app.asm to app.exe and allocate only 4 MB of memory, I could execute Fasm as follows:

fasm.exe app.asm app.exe 4096

What do you think? But even if you don't agree, I am still happy with the current working variant.

It would be more siutable with:

-a for allocate (possibly --allocate for linux versions)
it's better with a switch so one don't need to specify it every time, or we might end up with compile lines like:

I would fully agree with:

The question is... will Privalov agree with it.

But, scientica, there will never be such command lines anyway like:

The other arguments are placed inside the source. Only the memory allocation argument (beside the source.asm and output.exe) would be in the command line.

Yes, I think it would be good to implement such switch (I'd prefer to use -m 4096 form), also for the Linux version.

Yes, it would be great!

Thanks Privalov!

You see the problem lies in the fact that in my customization of fasmw (named Phantome) the -m switch is used for make (and -r for fun).
So to me -a (as in allocate (memnory) is more siutable).

But you are the master and author of fasm, if you want that switch to be -m then I'll have to find some other "switch name". I bow before thee for thou are root.

Is that feature is enabled in Linux version? I don't see it
I run compiler end it tells me that there's now free memory. I've got 300MB free memory (640MB total). If Linux version uses half of memory then it's too much for my purposes. It is a little difficult to recompile fasm sources with other values since there's almost always half of the memory is used.

Is that line switching feature is forgotten?

(Fasm 1.51, FreeBSD 5.1).