                       Falcon Screen Resolution Detecting
                       ==================================

                  by Richard Davey (fog@walusoft.centron.com)

     FALCON SCREEN RESOLUTIONS
     =========================

     One major problem I had  when  making  my programs was detecting which
     damn screen resolution the  user  was  loading  my programs in.  Could
     they be in a weird True  Colour  resolution?   If  they have a VGA, do
     they have the Double Line  On  or  Off  ?   All these questions and no
     obvious answer made me fiddle around and here is what I found...

     SYSTAB & GETREZ%
     ================

     Both these calls are supposed to  be  used independently, but with the
     amount of resolutions on the  Falcon  it  makes sense to combine their
     results  to  find  out  the  correct  resolution  and  warn  the  user
     accordingly.

     r%=peekw(systab)
     g%=getrez%

     The above are the methods used from  within HB.  You will need to have
     the Xbios library installed for the getrez  command to work or else it
     will return a value of 0 each time regardless.

     VGA WARNING
     ===========

     I am yet to test my results on  an  RGB monitor, or indeed a TV should
     that be any different, so  for  the  meantime  here are the results as
     tested on a Samsung VGA.

     RESULTS!
     ========

     Falcon Resolution                SYSTAB    GETREZ
     -------------------------------------------------
     4 colour, 40 column, DL Off        2         7
     4 colour, 80 column, DL Off        2         2
     4 colour, 40 column, DL On         2         0
     4 colour, 80 column, DL On         2         1

     16 colour, 40 column, DL Off       4         7
     16 colour, 80 column, DL Off       4         2
     16 colour, 40 column, DL On        4         0
     16 colour, 80 column, DL On        4         1

     256 colour, 40 column, DL Off      8         7
     256 colour, 80 column, DL Off      8         2
     256 colour, 40 column, DL On       8         0
     256 colour, 80 column, DL On       8         1

     True Colour, 40 column, DL Off     16        7
     True Colour, 40 column, DL On      16        0

     ST LOW                             4         0
     ST MED                             2         1
     ST HIGH                            1         2

     THAT'S IT!
     ==========

     I am sure you can see  from  the  above  table that when you check the
     systab and getrez results if they equal  16  and 7 then the user is in
     the True Colour, 40 column, Double Line Off mode... and so on...

     PROBLEM
     =======

     There is only one problem though.   The  ST  LOW results (4/0) are the
     same as the 16  colour,  40  column,  Double  Line  On (4,0).  This is
     because essentially they are the same  screen dimensions but you still
     might like to know which one of the  two it is.  Well I can't help you
     here I am afraid but if anyone out there can then PLEASE get in touch!

     CONTACT
     =======

     Falcon owning, HiSoft Basic  programming  people  please  get in touch
     with me to swap ideas and routines.

     Richard Davey, 10 Oak Drive, Portishead, Bristol, BS20 8QS, UK.
     Phone: +44 (0) 275 843241
     Email: requiem@armory.com

     The email will become active again  during October 1994.  Please allow
     some time for  a  reply  as  all  mail  is  forwarded  to  me  when at
     University.

     Anyone who wants details about the FALCON  OWNERS GROUP just send me a
     single first class stamp and your address.
