AMPEX is an acronym, created by its founder, Alexander M. Poniatoff. It actually means (A)lexander (M). (P)oniatoff (Ex)cellence. Poniatoff's company was born in 1944 as the Ampex Electric and Manufacturing Company.
In 1948, ABC used an Ampex Model 200 audio recorder for the first-ever U.S. tape delay radio broadcast of The Bing Crosby Show.
In 1950, Ampex introduced the first "dedicated" instrumentation recorder, Model 500, built for the U.S. Navy.
Ampex became a leader in magnetic recording technology, both sound and video. Ampex was not a recording format, per se, but a company that invented the quadruplex format that dominated the broadcast industry for decades. The format was licensed to RCA for use in their "television tape recorders." Ampex's invention revolutionized the television industry by eliminating the kinescope process of archiving television programs on motion picture film (at least in the U.S. - in Britain, the BBC and most of the ITV companies continued to use kinescoping alongside videotape until the late 1960s.) The Ampex broadcast video tape recorder also facilitated time-zone broadcast delay so that networks could air programming at the same hour in various time zones.
One of the key engineers in the development of the quadruplex video recorder for Ampex was Ray Dolby, who went on to form Dolby Laboratories, a pioneer in audio noise reduction systems.
The first television program recorded on the new Ampex Quadruplex recording system was "CBS News with Douglas Edwards" in Oct 1956.
Since the early 1950s, Bing Crosby and others tried to record video on very fast-moving magnetic tape. One semi-successful attempt was the BBC's VERA.
Only Ampex had the wisdom to rotate the heads at high speed and keep tape movement slow. The "Quad" head assembly has 4 heads that rotate at 14,400 rpm. They write the video vertically across the width of a tape that is 2 inches (5 cm) wide and runs at 15" (38cm) per second. This allows programs of one hour to be recorded on one reel of tape. But in 1956 one reel of tape cost 300 dollars. The machines themselves cost about 75 to 100 thousand dollars. So the only videotaped archives that exist are network programs as the typical television station could not afford an Ampex VTR. RCA called them "television tape recorders."
In 1967, ABC used the Ampex HS-100 disk recorder for playback of slow-motion downhill skiing on World Series of Skiing in Vail, Colorado. Thus began the use of slow motion instant replay in sporting events. Also, that year, Ampex introduced the Ampex VR-3000 portable broadcast video recorder, which revolutionized the recording of high-quality television in the field, without the need for long cables and large support vehicles. Broadcast quality images could now be shot anywhere, including out of airplanes, helicopters and boats.
In 1970, Ampex introduced the ACR-25, the first automated robotic library system for the recording and playback of television commercials. Each commercial was recorded on an individual cartridge. These cartridges were then loaded into large rotating carousels. Using sophisticated mechanics and compressed air, the "carts" were able to be loaded into and extracted from the machine at extremely high speed. This allowed TV stations to re-sequence commercial breaks at a moments notice, adding, deleting and rearranging commercials at will. The TV newsroom also began to use the ACR-25 to run news stories because of its random access capability.
The Ampex video system is now obsolete. Those machines which still survive have been pressed into service to transfer recordings onto modern digital video formats.
Deleted "in 1956 money" as an awkward construction, but conversion to current values would be useful.
Someone should mention that AMPEX tape was professional audio industry standard, and maybe mention Quantegy.