freepascal.compiler/docs/go32ex/meminfo.pas

{ Shows how to obtain memory information via get_meminfo();

notice the checks if any of the returned information is invalid (-1)
}

uses
	go32;

var
	meminfo : tmeminfo;

begin
	get_meminfo(meminfo);
	if (int31error <> 0)  then begin
		Writeln('Error getting DPMI memory information... Halting');
		Writeln('DPMI error number : ', int31error);
	end else begin
		with meminfo do begin
			Writeln('Largest available free block : ',
				available_memory div 1024, ' kbytes');
			if (available_pages <> -1) then
				Writeln('Maximum available unlocked pages : ',
					available_pages);
			if (available_lockable_pages <> -1) then
				Writeln('Maximum lockable available pages : ',
					available_lockable_pages);
			if (linear_space <> -1) then
				Writeln('Linear address space size : ',
					linear_space*get_page_size div 1024, ' kbytes');
			if (unlocked_pages <> -1) then
				Writeln('Total number of unlocked pages : ',
					unlocked_pages);
			if (available_physical_pages <> -1) then
				Writeln('Total number of free pages : ',
					available_physical_pages);
			if (total_physical_pages <> -1) then
				Writeln('Total number of physical pages : ',
					total_physical_pages);
			if (free_linear_space <> -1) then
				Writeln('Free linear address space : ',
					free_linear_space*get_page_size div 1024,
					' kbytes');
			if (max_pages_in_paging_file <> -1) then
				Writeln('Maximum size of paging file : ',
					max_pages_in_paging_file*get_page_size div 1024,
					' kbytes');
		end;
	end;
end.