PLZ/SYS(ID:3983/plz004)

HIgh level dialect of PLZ for Zilog Z-80
Related languages
PLZ => PLZ/SYS   Dialect of
References:
  • Bass, Charlie "PLZ: a family of system programming languages for microprocessors" pp34-39. view details
          in Computer 11(3) (March 1978) view details
  • Snook, Tod et al, "Report on the Programming Language PLZ/SYS", Springer 1978. view details
          in Computer 11(3) (March 1978) view details
  • Burkowski, F. J. - Review of Bass view details Extract: Review
    PLZ: a family of system programming languages for microprocessors.
    34,933
    BASS, CHARLIE
    PLZ: a family of system programming languages for micro- processors.
    Computer 11, 3 (March 1978), 34-39.

    The author has written an interesting and informative review of the salient features and functional capabilities of PLZ, a "family" of system programming languages for microprocessors.

    At the present time, the PLZ family has two members: PLZ/ASM and PLZ/SYS. The family will eventually expand to encompass languages which handle list processing applications, mathematics in scientific applications, and text processing.

    Each language in the PLZ family is based on a "kernel" grammar; i.e., they are syntactically similar while still maintaining an identity in terms of level. Thus, PLZ/ASM is a low-level language built by adding Z80 assembly language instructions to the kernel framework, while PLZ/SYS is a high- level language.

    The control statements in PLZ/ASM primarily generate test and branch instructions which do not interfere with the programmer's control of register values or condition codes. In contrast, PLZ/SYS does not permit any direct access to machine operations. The principal construct added is an assignment statement with conventional algebraic notation.

    While the cost of software often equals that of hardware in mainframe systems, it can totally dominate the economics of a microcomputer-based system. In this context, improvement is usually measured in terms of reliability, time to completion, and flexibility. Thus, PLZ has addressed itself to the problems of providing efficient tools for "structured programming. " In an effort to provide these tools, PLZ has constructs which organize programs into procedures and blocks. This approach tends to reinforce desirable programming practices.

    A system programming language designed microcomputer should have the following characteristics which have been stressed in the design of PLZ: it should 1) reinforce good programming practices, 2) manage system resources, 3) allow access to the architecture of the machine, 4) produce efficient code, and 5) be relatively easy to compile. The author has provided more details relating to the above list and has presented some examples of source code.

    Although it might be argued that the presence of a common kernel grammar would hinder the syntactic strength of low-level and high-level compilers, the author presents a convincing argument in support of such a feature.

    F. J. Burkowski, Winnipeg, Manitoba, Canada

          in ACM Computing Reviews 20(08) August 1979 view details