National Aeronautics and Space Administration

Creating a new SYS.xxx routine

Before you can run QDP you will need to create one other system dependent file called XANADU:[LIB.XANLIB]SYS.xxx. As described below, not all routines in SYS.xxx need to be fully implemented in order to use QDP/PLT. In addition, some of the routines are used by other parts of the XANADU software and are not needed by QDP/PLT This section only deals with the routines that are needed by QDP/PLT.

The following routines are implemented in standard Fortran in SYS.SUN and therefore you should be able use that version without modification:

FRELUN   Free up a logical unit number
GETLUN   Get a free logical unit number
LOCASE   Convert to lower case
UPC      Convert to upper case

The following routines can be considered optional in that QDP/PLT will still work if these routines do nothing. Of course, implementing these routines will increase the usefulness of QDP/PLT.

CONC     Converts filename to system preferred case
PLTTER   Toggle graphics/alpha mode on terminal
RDFORN   Read a foreign command, i.e., the command line
SPAWN    Spawn to the operating system

The last set of routines need to be implemented, although in many cases some loss of functionality is allowed. For example, subroutine PROMT must display the prompt. It would be nice if the cursor was left at the end of the prompt line, but if you don't know how to do that on your system, use a standard Fortran write operation.

DIRPOS   Return the number of characters in directory spec
OPENWR   Wrapup for the Fortran OPEN statement
PROMPT   Write a prompt on the user's terminal
PTEND    Add prefix (disk and directory name) to file names
TRLOG    Translate logical name/environment variable