Method of visual signaling, usually with flags or lights. Before radio, a semaphore system was widely used to send messages between ships. A person would stand with arms extended, moving two flags to specific angles to indicate letters or numbers. Before the invention of the telegraph, semaphore signaling with lights on high towers was used to transmit messages between distant points; messages were read by telescope. Modern semaphores have included movable arms or rows of light simulating arms, displayed from towers and used to signal railroad trains.
Learn more about semaphore with a free trial on Britannica.com.
Dual-port SRAMs provide semaphores for software memory arbitration. (static random access memory) (Cypress Semiconductor)
May 21, 1992; A 4-member family of dual-port static RAMs (SRAMs) provides on-chip logic that helps simplify memory-access arbitration in...
Processor Module supports automation and SCADA applications.(Semaphore Announces Processor with Integrated SHDSL for RTU Product Line)
Mar 28, 2012; Based on 32-bit, 505 MIPS PowerPC processor, Model MS-CPU32X supports up to 20 serial ports in T-BOX MS RTU installation. Unit...