Pattern buffer
The pattern buffer was a key component of transporter, holodeck, and replicator systems.

Transporters 

For transporter systems, pattern buffers were also synonymously referred to as a transporter buffer, transporter pattern buffer, transport pattern buffer, or simply transport buffer.

The buffer was used during matter-energy conversion to temporarily store the matter stream following dematerialization, but prior to sending the stream to its target. This was done because of the relative motion of transporter and target. By temporarily storing the matter stream, the Doppler compensators had enough time to adjust the targeting scanners.

Once a pattern was in the buffer, transport could no longer be blocked. ()

The buffer capacity could be expanded, "in a pinch", to transport several dozen occupants at a time. This was not usually a preferred method of operation on account of safety reasons. () 

The transporter buffer performs it's own version of a microcellular scan every time someone uses it. In reviewing transporter logs, it was possible to observe the first time an anomalous reading might have appeared in an individuals molecular pattern. ()

A matter stream could not be stored indefinitely in the buffer. The only known occurrence of a person surviving in a buffer longer than the theoretical maximum was Captain Montgomery Scott on board the . Following the Jenolans crash landing on a Dyson sphere, Scott, with the help of Matt Franklin, was able to store his pattern in the buffer for 75 years. This was achieved by disabling the rematerialization subroutine, connecting the phase inducers to the emitter array, bypassing the override, and locking the buffer into a continuous diagnostic cycle. Although Captain Scott's pattern suffered less than 0.003% degradation, and was successfully recovered by Geordi La Forge of the  in 2369, Franklin was irretrievable, as one of the inducers had failed, causing a 53% degradation in his pattern. ()

In 2152, diamagnetic storms saturated with polaric energy were encountered on a planet visited by the crew of the starship . The storms interfered with the operation of the ship's transporter, resulting in Hoshi Sato being trapped in its pattern buffer for 8.3 seconds while Malcolm Reed worked to reintegrate the matter stream. ()

A pattern buffer malfunctioning was the leading cause of transporter accidents. In the 2270s, during the V'ger incident, Commander Will Decker and Lieutenant Cleary did repairs on the pattern buffer but it malfunctioned while Cleary was replacing the transporter sensor. Janice Rand attempted to beam Commander Sonak and a female officer aboard the Enterprise but they were both killed. Scotty later repaired the pattern buffer and the sensor in time to beam Ilia and Leonard McCoy aboard. ()

On  starships, the pattern buffer was located immediately beneath the transporter pad. ()

In 2367, when Lwaxana Troi became agitated upon not being allowed to transport to Kaelon II and her daughter tried to talk her down, Miles O'Brien stated that he would go check the pattern buffers and left to give the two privacy. ()

When weapons were beamed to a rebel camp on Krios from a cargo transporter of the Enterprise-D that same year, Miles O'Brien asked Geordi La Forge if he could check the reliability of the pattern buffers. ()

When Jadzia Dax decided to stay on Meridian in 2371, the transporter buffer of the  was used to bring her quantum matrix in sync with that of the Meridians. ()

In 2372, Odo began to experience the effects of an unknown affliction that he had acquired from his fellow Changelings, which caused the destabilization of his molecular structure. When it was proposed that he be ferried aboard the  to the Founders' new homeworld, the crew had to wait for Odo to carry himself aboard the ship. When it was questioned why he couldn't go through the transporter, Doctor Julian Bashir explained that "his molecular structure is scrambled enough as it is," adding, "[t]he last thing he needs is a trip through a transporter buffer." ()

When the Orion Syndicate planted a bomb on board the , Odo was able to mitigate the damage from the bomb by beaming it out and channeling the explosion through the transporter buffer. ()

Starships could also transfer patterns from one pattern buffer to another by "locking on" to the target buffer and energizing. ()

To eliminate the medical condition called transporter psychosis, Federation transporters were equipped with multiplex pattern buffers. ()

The transporter buffer of an  starship performed a version of a microcellular scan every time it was used. ()

Cardassian transporter systems were still equipped with active feed pattern buffers in 2367; these were considered less advanced by Starfleet standards. ()

In 2374, the crew of Voyager overloaded the ship's pattern buffers attempting to transport deuterium from beneath the surface of a Y-class planet. ()

In 3190, while investigating a subspace rift, the crew of the  except its captain Michael Burnham was maintained in the ship's pattern buffers for more than 10 minutes, in order to save them from the ship's disintegration by Galactic barrier particles. ()

Holodecks 
A pattern buffer was also a component used in holodecks, where it was referred to as the holodeck buffer, holo-buffer, or even just "the holodeck's pattern buffer." ()

Replicators 
Pattern buffers were also a component used in replicator systems, and were referred to as the replicator buffers. ()
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Transporter technology
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