Editing HAL/S (section)

==Goals and principles==
The three key principles in designing the language were reliability, efficiency, and [[Software portability|machine-independence]]. The language is designed to allow aerospace-related tasks (such as [[vector (geometry)|vector]]/[[matrix (mathematics)|matrix]] arithmetic) to be accomplished in a way that is easily understandable by people who have spaceflight knowledge, but may not necessarily have proficiency with computer programming.

HAL/S was designed not to include some constructs that were thought to be the cause of [[computer bug|error]]s. For instance, there is no support for dynamic memory allocation. The language provides special support for [[real-time computing|real-time]] execution environments.

Some features, such as "[[GOTO]]" were provided chiefly to ease mechanical translations from other languages.<ref name="hal-s-specification-nov2005"/> (page 82) <ref>{{Cite web|url = https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790006637.pdf|title = Programming in HAL/S|date = 1979|access-date = 2016-02-14|website = |publisher = Source: NASA Technical Reports Server|last = Ryer|first = Michael J.}}</ref>

"HAL" was suggested as the name of the new language by Ed Copps, a founding director of [[Intermetrics]], to honor Hal Laning, a colleague at [[MIT]]. On the Preface page of the HAL/S Language Specification,<ref name="hal-s-specification-nov2005" /> it says,
{{bquote|fundamental contributions to the concept and implementation of MAC were made by Dr. [[J. Halcombe Laning]] of the [[Draper Laboratory]].}}

A proposal for a NASA standard ground-based version of HAL named HAL/G for "ground" was proposed, but the coming emergence of the soon to be named [[Ada (programming language)|Ada]] programming language contributed to Intermetrics' lack of interest in continuing this work. Instead, Intermetrics would place emphasis on what would be the "Red" finalist which would not be selected.

Host compiler systems have been implemented on an IBM 360/370, [[Data General Eclipse]], and the [[MODCOMP|Modcomp]] IV/Classic computers. Target computer systems have included [[IBM 360|IBM 360/370]], [[IBM System/4 Pi|IBM AP-101]] (space shuttle avionics computer), Sperry 1819A/1819B, [[Data General Nova]] and Eclipse, CII Mitra 125, Modcomp II and IV, [[NASA Std. Spacecraft Computer-l]] and Computer-2, [[ITEK ATAC]] 16M ([[Galileo (spacecraft)|Galileo Project]]), and since 1978 the [[RCA 1802|RCA CDP1802 COSMAC]] microprocessor (Galileo Project and others).<ref name=Lytle-1981>{{Cite web|url=https://archive.org/details/NASA_NTRS_Archive_19810022530|title=Current Status of the HAL/S Compiler |last=Lytle|first=P.J. |date=1981|website=|access-date=}}</ref>