Food cards used in the food synthesizers
A food synthesizer
A voice commanded food synthesizer
The food synthesizer (or food processor) was a common receptacle used aboard 23rd century starships and starbases for synthesizing foods and beverages. These food receptacles served as a supplement to the ship's chef and were predecessors to 24th century replicators. Unlike replicators, where food orders were made by voice command -- food orders given to food synthesizers were made by program tapes or cards inserted into a slot.
Food synthesizers were located in numerous locations throughout Template:ShipClass starships, including the transporter room. (TOS: "Tomorrow is Yesterday")
In 2268, while the USS Enterprise was infested with tribbles, it was discovered that they had gotten into the food processors aboard the ship through one of the ship's air vents. (TOS: "The Trouble with Tribbles"; DS9: "Trials and Tribble-ations")
One of the reasons Rojan cited for neutralizing non-essential Enterprise personnel during the trip to the Andromeda Galaxy was to conserve the food synthesizer's resources. (TOS: "By Any Other Name")
Nurse Chapel offered the surviving children of the Starnes Exploration Party a selection of cards with differing flavors of ice cream to choose from. All they had to do was pick a card and the computer would mix their favorite combination. (TOS: "And the Children Shall Lead")
Upon taking on a contingent of Klingon officers, lead by Kang, aboard the Enterprise, Captain Kirk ordered Johnson to have the food synthesizers programmed to accommodate their guests. (TOS: "Day of the Dove")
By 2270, the food synthesizers aboard the Enterprise were converted over to a voice command ordering system. (TAS: "The Practical Joker")
Romulan D7 class battle cruisers were also equipped with food synthesizers. (TAS: "The Practical Joker")
The term was still used occasionally while explaining the more advanced replicator to others. (TNG: "The Vengeance Factor")