Assembly language

Programming for the microcomputer is done in assembly language and cross assembled on the minicomputer. Details of the mini-microcomputer system and its organization have been reported elsewhere (1,2,3). 

If a "P" is typed in response to the query "SCOPE, PLOTTER, OR EXIT" then control will be given to an assembly language program that is designed to format the spectral data so chromatographs may be plotted. 

LABPAC. LABPAC is sold by the manufacturer of the LabMaster board (TecMar) and supports only this card. LABPAC consists of a collection of assembly language subroutines which can be called from high level languages like BASIC, Pascal or FORTRAN. 

SALT. SALT is a threaded interpretive language which is interfaced to BASIC. Thus it exhibits both the fast response of assembly language programs and the interactive character of BASIC programs. SALT was written by a researcher who emphasized the ability of instrument control. SALT supports only the TecMar LabMaster hardware. 

It is worth pointing out that the vectorised code is written in standard FORTRAN. The CRAY FORTRAN compiler simply recognises the vectorisable loops and translates these into hardware vector orders. An inspection of the machine code thus generated revealed that very little was to be gained by hand coding the kernels into Assembly language. 

The question of special purpose routines for structural chemistry will be discussed later and attention will now be directed to the construction of the library. It would have been possible to write a small number of strategic routines in Z80A/MVP-9500 assembly language and the remainder of the library in FORTRAN code which made use of the assembler level nucleus. 

This would certainly have resulted in an operational library in the shortest possible time but at considerable sacrifice in efficiency. All of the VPLIB subroutines were therefore written entirely in Z80A/MVP-9500 assembly language and this produced modules which contained, on average, one third of the assembler instructions produced by F80 for the same operation coded in FORTRAN. In addition to these straightforward savings a considerable amount of hand optimization was possible on the assembler level subroutines. 

Assembly Language FDA (1995) A low-level programming language that corresponds closely to the instruction set of a given computer, allows symbolic naming of operations and addresses, and usually results in a one-to-one translation of program instructions (mnemonics) into machine instractions. 

Instruction Set Architecture—the abstract image of a computing system that is seen by a machine language (or assembly language) programmer. This inlcudes the instruction set, memory address modes, processor registers, and address and data formats. 

Implementation Problems. A discussion of problems encountered during implementation of the SECS program follows in three parts problems in converting the assembly language... 

Thus, the dynamic array allocation routines, the list processing routines, and most of the GT42LIB routines were rewritten in FORTRAN. The bit packing and unpacking routines and the logical set manipulation routines were rendered into IBM assembly language ... 

In the process of implementing the UTIL routines, whether in FORTRAN or assembly language, extensive error checking of passed arguments was incorporated to facilitate the location of errors introduced in implementing other parts of the program. 

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