
           HiSoft DevPac Assembler MACRO Definition Reference Sheets
           =========================================================
                                 By Peter Hibbs
                                 --------------

     The HiSoft  DevPac  Assembler  comes  with  a  complete  set  of MACRO
     definitions for the GEM AES/VDI functions  which can save a programmer
     a lot of time and also make  the  source code easier to use and debug.
     The Assembler manual lists  all  the  MACRO  functions available along
     with the names  of  parameters  which  must  be  passed  to the MACRO.
     Unfortunately this list does not  tell  the programmer the function of
     each parameter and while some  are  pretty  obvious, others need to be
     looked up in a GEM reference  book.  Also the parameters returned from
     each MACRO (where relevant) are  not  mentioned  at  all in the DevPac
     manual. Another problem that I have  found  is  that the arrays in the
     HiSoft definitions  do  NOT  tally  with  my  'GEM  on  the  Atari ST'
     reference book although they  do  tally  with  the 'Compute' series of
     books, for example the int_out  and  int_in arrays have the underscore
     character missing in the first book.  Yet  another problem is that the
     DevPac manual (even in the DevPac 3 issue) has errors, the ptsin array
     is shown as the intin array in the VDI section.

     All the above problems make programming more error prone than it needs
     to be and so I have produced a number of reference sheets which define
     each MACRO together with the  parameters required, a brief description
     of each parameter and  the  location  and  function  of any parameters
     returned by the MACRO. The MACROs are  listed  in the same order as in
     the DevPac manual. Bear in  mind,  however,  that these are still only
     quick reference sheets, you will  still  need good reference books for
     details on each GEM function but they  are much easier to use than the
     DevPac manual and several GEM books.

     I have found the reference sheets easier to use if the AES and the VDI
     sections are printed on  different  coloured  paper  and then inserted
     into a clear plastic pockets folder  that should be available from any
     W H Smiths. If the file  MACRODAT.DOC  is loaded into a word-processor
     and tidied up (with only a few functions crossing page boundaries) the
     document should need about 35 pages. The data is easier to read if the
     headings and MACROs are printed in  bold  and parameters which are not
     defined in the MACRO itself (such as the data that goes into the ptsin
     array for example) is printed in italics.

     The  file  is  also  available   in  Protext  format  (including  text
     formatting codes, of course) if required,  just send a disk and return
     postage to me at ICTARI. I can also provide a printed copy if required
     for a small fee, contact me for more details if you are interested.
