GNU Fortran (version 3.4.6 release 3)

How set up a simple application to run the GNU Fortran for RISC-OS

GNU Fortran requires a machine with at least 4Mbytes free application space
This version is claimed to be 32-bit (Iyonix) compatible.

If you already have this GNU Fortran set up and want the PGPlot package, click here

• Download the skeleton application (!GNUF77, 61 Kbytes) and unzip it to a suitable directory
• Download the g77.zip (2.15 Mbytes).
• Download the gcc.zip (2.51 Mbytes)
• the g77.zip just contains an application called !gcc. Extract the files:
  • !gcc.bin.g77
    to your new !GNUF77.bin.g77
  • !gcc.bin.arm-riscos-aof.3_4.f771
    to !GNUF77.bin.f771
  • !gcc.bin.arm-riscos.3_4.apcs32.abs.unixlib.o.libg2c
    to !GNUF77.bin.o.libg2c
  • there is also a directory of docs which you may find useful. The file g77-readme has a list of error numbers and the file g77 has all the possible compiler options. You should read the beginnings of these to be aware of the GNU license.
• the gcc.zip also contains an application !gcc. Extract the files:
  • !gcc.bin.arm-riscos-aof.3_4.as
    to !GNUF77.bin.as
  • !gcc.bin.arm-riscos-aof.3_4.apcs32.abs.unixlib.o.libgcc
    to !GNUF77.bin.o.libgcc
  • !gcc.bin.arm-riscos-aof.3_4.apcs32.abs.unixlib.o.unixlib
    to !GNUF77.bin.o.unixlib
  • !gcc.bin.gcc
    to !GNUF77.bin.gcc
  • !gcc.bin.drlink
    to !GNUF77.bin.drlink
• (you would normally have to download the system.zip but this just has a module which is already in the skeleton application)
• all the information needed has now been extracted from the downloaded zip files so you could delete them now.

There is a rudimentary interface to RISC-OS in our library called ‘OSlibN32’ which contains many of the functions of the Utils, Graphics and SpriteOps libraries defined in our free distribution for Fortran release 2. This library has had little testing so far, (Oct 2004), we can do more testing and extend it further if there is any interest.

Now you should be ready to compile, link and run a simple Fortran program.
Double-click on the !GNUF77 which sets up system variables and opens the directory ‘myprogs’ containing the source subdirectory ‘f’ with the trivial program ‘Hello’.
The obey files ‘clr’ and ‘clrOpt’ will compile, link and run a Fortran program, either unoptimized or optimized.
‘clr’ or ‘clrOpt’ request a 4Mbyte chunk of memory for the compiler. This is not necessary for short programs and can be reduced to 3Mbytes if you only have a 4Mbyte computer (use !Edit to change the second line of these Obey files appropriately).
Open a task window (Ctrl+F12) and type ‘clr hello’ to see it perform.
It will create a directory ‘o’ with the object code and place the run image directly into ‘myprogs’.

GNU Fortran and the PGPlot graphics package

Bugs we have found

1. unable to open a file with a name with a ‘/’ in it;
   unhelpful for files with DOS extensions
   no change from previous version;
2. reading integers which are too big for the word size does not report an error, it just gives a wrong result;
   no change from previous version;
3. does not allow trailing blanks in I/O keywords;
   no change from previous version;
4. integer division by zero gives the diagnostic ‘Floating Exception’;
   no change from previous version.

Please send any comments to us here.

Good Luck!