external paging system
21Protected mode — This article is about an x86 processor mode. For Internet Explorer Protected Mode, see Mandatory Integrity Control. x86 processor modes Mode First supported Real mode Intel 8086 8080 emulation mode NEC …
22Public address — This article is about audio systems. For IP addresses, see IP address. Horn loudspeakers are often used to broadcast sound to outdoor locations A public address system (PA system) is an electronic amplification system with a mixer, amplifier and… …
23TOPS-20 — Infobox OS name = TOPS 20 logo = caption = developer = Digital Equipment Corporation source model = ? kernel type = ? supported platforms = PDP 10 ui = Command line interface family = DEC OS family latest release version = ? latest release date …
24NORD-10 — Two adjacent NORD 10/S systems NORD 10 was a medium sized general purpose 16 bit minicomputer designed for multilingual time sharing applications and for real time multiprogram systems, produced by Norsk Data. It was introduced in 1973. The later …
25Hospital emergency codes — For the computer virus, see Code Red (computer worm). For the Portall Album, see Code Black (album). For the Iceahouse Album, see Code Blue (album). For the practice of corruption among U.S. law enforcement, see Blue Code of Silence. Hospital… …
26AT&T Merlin — 5 button telephone (voice terminal) manufactured in early 1985 The AT T (also Lucent, now Avaya) Merlin telephone system was introduced in late 1983, branded American Bell Merlin. After the breakup of AT T in 1984, it was rebranded AT T Merlin.… …
27Civil defense siren — Federal Signal Thunderbolt 1003 Civil Defense siren. A civil defense siren (also referred to as an air raid siren, tornado siren, tsunami siren, fire siren/whistle, flood siren, weather siren, time/curfew siren, or other outdoor warning siren) is …
28Palm Beach County Fire-Rescue — Motto:  When seconds count, count on us Established 1984 Staffing Combination Career/Volunteer …
29Google Earth — Infobox Software name = Google Earth caption = Screenshot of Google Earth in Windows Vista developer = Google released = mid 2006 latest release version = 4.3.7284.3916 latest release date = release date and age|2008|7|13 programming language =… …
30JT Global — Type Subsidiary Industry Communications Founded 1888 Headquarters …
