Date   : Sun, 17 Feb 1985 19:06:56 PST
From   : bang!crash!ihom@nosc.ARPA
Subject: Re: changing user areas

The BDOS function code for "getting" and "setting" the user area is 20h.
The contents of register E determines whether to get or set.  If register
E contains FFh, then the curent user area is returned in register A.
Any other valid user number in register E will set you to that user.
i.e.
 
procedure change_users;
   const
      user_code = $0020;   { BDOS call }
      current = $FF;
   var
      new_user : byte;
   begin
      writeln('Current user is: ',bdos(user_code,current));
      write('New user? ');
      readln(new_user);
      bdos(user_code,new_user);
   end;

--Irwin Hom          {ihnp4, sdcsvax!bang}!crash!ihom
                                bang!crash!ihom@nosc
                              sdamos!crash!ihom@ucsd