Likely areas of incompatibility

There are a number of areas where incompatibilities between machines are likely to arise. These include:

1. Fortran OPEN statements. Modifications are likely to routines such as KUOPEN, RZOPEN, FMOPEN etc. In addition to various language extensions, such as the READONLY and SHARED attributes in VAX Fortran, the units in which the record length of direct access files often varies (typically bytes or words).
2. The syntax for file and directory names is likely to differ. This will affect packages such as , and amongst others.
3. Data representation. The majority of new systems support IEEE floating point. If your system does not support IEEE floating point format, then you will need to modify the KERNLIB package IE3CONV. If your system uses a floating point format that already exists, then you should find the appropriate code in one of the KERNLIB pam files. For example, the routines to convert to and from IBM floating point representation can be found in the KERNIBM pam file.
4. Byte order. Most systems are big endian, which corresponds to the way that we write numbers in every day life (i.e. the left most bit has the highest significance. Some systems, in particular DEC systems (VAX, Alpha, Ultrix) and IBM PCs and compatibles, are little endian.
5. Interface to the system. Routines in the KERNLIB package CINTF will probably require modification.
6. The graphics packages may require heavy modification depending on the graphics facilities on the target machine.