MIRIAD tasks should be written in Fortran-77. Though you should program in standard FORTRAN, two extensions will generally be needed by the programmer. Firstly MIRIAD \ uses both upper and lower case character strings (Fortran-77 strictly supports only upper case characters. However almost all compilers support both upper and lower case, and it would be a reasonably simple preprocessing job to convert all of MIRIAD to a strictly upper case system if the need ever arises). Generally MIRIAD routines are case-sensitive, with lower case being preferred.
Secondly MIRIAD tasks should use the maxdim.h include file where appropriate. This include file defines a parameter, maxdim, which gives the maximum image dimension that a task should be prepared to accept. Currently this is set to 4096, but by using maxdim to define needed storage, it should be reasonably easy to rebuild all MIRIAD tasks to handle larger images. The include file also defines a parameter maxbuf, which is a guide to the maximum amount of internal data storage that a program should contain.
Despite the encouragement to use this include file, programmers are generally discouraged from using include files and common blocks. This is far from a strict rule. Avoid them if you can.
See Chapter 3 for a description of some utilities which simplify the development of code.