Editing Apollo Guidance Computer (section)

==={{anchor|DSKY}} DSKY interface===
[[File:Apollo display and keyboard unit (DSKY) used on F-8 DFBW DVIDS683588.jpg|thumb|250px|Apollo computer DSKY user interface unit]]
[[File:Apollo DSKY interface.svg|thumb|250px|right|LM DSKY interface diagram]]
The [[user interface]] to the AGC was the ''DSKY'', standing for ''display and keyboard'' and usually pronounced ''"DIS-kee".'' It has an array of indicator lights, numeric displays, and a [[calculator]]-style keyboard. Commands were entered numerically, as two-digit numbers: [[Verb]] and [[Noun]]. ''Verb'' described the type of action to be performed and ''Noun'' specified which data were affected by the action specified by the Verb command.

Each digit was displayed via a green (specified as 530&nbsp;nm<ref>{{Cite web|url=https://www.youtube.com/watch?v=feRCZyLzAwA?t=1405|title = Apollo DSKY panel relight: The full story|website = [[YouTube]]| date=27 July 2021 }}</ref>) high-voltage [[electroluminescent display|electroluminescent]] [[seven-segment display]]; these were driven by electromechanical [[relay]]s, limiting the update rate. Three five-digit signed numbers could also be displayed in [[octal]] or [[decimal]], and were typically used to display [[vector (geometry)|vectors]] such as space craft [[Aircraft attitude|attitude]] or a required velocity change ([[delta-V]]). Although data was stored internally in [[International System of Units|metric units]], they were displayed as [[United States customary units]]. This calculator-style interface was the first of its kind.

The command module has two DSKYs connected to its AGC: one located on the main instrument panel and a second located in the lower equipment bay near a [[sextant]] used for aligning the [[inertial guidance]] platform. The lunar module had a single DSKY for its AGC. A [[flight director (aviation)|flight director attitude indicator]] (FDAI), controlled by the AGC, was located above the DSKY on the commander's console and on the LM.