What follow are my personal views. Others will disagree with them. None of the assembly-language texts I have looked at is a bad book.
In my view they all do, however, suffer from one radical defect. They treat the macro language late and inadequately. (Their discussions of the created set symbols that make possible the macro subroutines that do something important without generating any code at all are particularly inadequate.) For this and other reasons most mainframe assembly-language programmers underuse the macro language, again radically. Per se the assembly language of the HLASM is long-winded and detail-ridden. Using the macro language these defects can be much mitigated, all but eliminated. Even a measure of portability is achievable. I often use the macro language to generate machine instructions for Intel micropreocessors, z/OS utility control statements, and text in statement-level procedural languages like C and PL/I. Or again, list processing--the assembly-time use of linear lists, queues, binary-search trees, and the like--is easy to do using macro-language facilities. For this reason I strongly recommend that you study and use the macro language in parallel with learning how to use the machine and assembler instructions. John Gilmore, Ashland, MA 01721 - USA
