From www.absoluteastronomy.com, a badly formatted text about the AGC and the HP-65 which I have taken the liberty of correcting:

Dsky user interface

The user interface unit was called the Dsky. Dsky stood for display and keyboard and was usually pronounced dis-key. It had an array of numeric displays and a calculator-style keyboard. Commands were entered numerically, as two-digit numbers: program, verb, and noun. The numerals were green high-voltage electroluminescent seven segment displays. The segments were driven by electromechanical relays, which limited the display update rate (Block II used faster silicon controlled rectifiers). Three 5-digit signed numbers could also be displayed in octal or decimal. These were typically used to display vectors such as space craft attitude or a required velocity change (delta-V). This calculator-style interface was the first of its kind, the prototype for all similar digital control panel interfaces.

The first advanced desktop calculators hit the market in roughly the same time frame, with scientific and then programmable pocket calculators appearing during the following decade. The first programmable handheld calculator, the HP-65, was tried on backup computations aboard the Apollo Command/Service Module in the Apollo-Soyuz Test Project in 1975.

The command module (CM) had two Dskys; one located on the main instrument panel and another located in the lower equipment bay near a sextant used for aligning the inertial guidance platform. Both Dskys were driven by the same AGC. The lunar module (LM) had a single Dsky for its AGC. A Flight Director Attitude Indicator (FDAI), controlled by the AGC, was located above the Dsky on the commander’s console and on the LM.

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