+=item C<OS2::Error(do_harderror,do_exception)>
+
+Returns C<undef> if it was not called yet, otherwise bit 1 is
+set if on the previous call do_harderror was enabled, bit
+2 is set if if on previous call do_exception was enabled.
+
+This function enables/disables error popups associated with
+hardware errors (Disk not ready etc.) and software exceptions.
+
+I know of no way to find out the state of popups I<before> the first call
+to this function.
+
+=item C<OS2::Errors2Drive(drive)>
+
+Returns C<undef> if it was not called yet, otherwise return false if errors
+were not requested to be written to a hard drive, or the drive letter if
+this was requested.
+
+This function may redirect error popups associated with hardware errors
+(Disk not ready etc.) and software exceptions to the file POPUPLOG.OS2 at
+the root directory of the specified drive. Overrides OS2::Error() specified
+by individual programs. Given argument undef will disable redirection.
+
+Has global effect, persists after the application exits.
+
+I know of no way to find out the state of redirection of popups to the disk
+I<before> the first call to this function.
+
+=item OS2::SysInfo()
+
+Returns a hash with system information. The keys of the hash are
+
+ MAX_PATH_LENGTH, MAX_TEXT_SESSIONS, MAX_PM_SESSIONS,
+ MAX_VDM_SESSIONS, BOOT_DRIVE, DYN_PRI_VARIATION,
+ MAX_WAIT, MIN_SLICE, MAX_SLICE, PAGE_SIZE,
+ VERSION_MAJOR, VERSION_MINOR, VERSION_REVISION,
+ MS_COUNT, TIME_LOW, TIME_HIGH, TOTPHYSMEM, TOTRESMEM,
+ TOTAVAILMEM, MAXPRMEM, MAXSHMEM, TIMER_INTERVAL,
+ MAX_COMP_LENGTH, FOREGROUND_FS_SESSION,
+ FOREGROUND_PROCESS
+
+=item OS2::BootDrive()
+
+Returns a letter without colon.
+
+=item C<OS2::MorphPM(serve)>, C<OS2::UnMorphPM(serve)>
+
+Transforms the current application into a PM application and back.
+The argument true means that a real message loop is going to be served.
+OS2::MorphPM() returns the PM message queue handle as an integer.
+
+See L<"Centralized management of resources"> for additional details.
+
+=item C<OS2::Serve_Messages(force)>
+
+Fake on-demand retrieval of outstanding PM messages. If C<force> is false,
+will not dispatch messages if a real message loop is known to
+be present. Returns number of messages retrieved.
+
+Dies with "QUITing..." if WM_QUIT message is obtained.
+
+=item C<OS2::Process_Messages(force [, cnt])>
+
+Retrieval of PM messages until window creation/destruction.
+If C<force> is false, will not dispatch messages if a real message loop
+is known to be present.
+
+Returns change in number of windows. If C<cnt> is given,
+it is incremented by the number of messages retrieved.
+
+Dies with "QUITing..." if WM_QUIT message is obtained.
+
+=item C<OS2::_control87(new,mask)>
+
+the same as L<_control87(3)> of EMX. Takes integers as arguments, returns
+the previous coprocessor control word as an integer. Only bits in C<new> which
+are present in C<mask> are changed in the control word.
+
+=item OS2::get_control87()
+
+gets the coprocessor control word as an integer.
+
+=item C<OS2::set_control87_em(new=MCW_EM,mask=MCW_EM)>
+
+The variant of OS2::_control87() with default values good for
+handling exception mask: if no C<mask>, uses exception mask part of C<new>
+only. If no C<new>, disables all the floating point exceptions.
+
+See L<"Misfeatures"> for details.
+