Civil Rights
Movements, leaders, victories and the continuing fight for equality.
Explore the people, places, events, achievements, struggles and stories that shaped our journey.
Movements, leaders, victories and the continuing fight for equality.
Innovation, patents, science, technology and world-changing contributions.
Pioneers, champions, Negro Leagues, records, activism and excellence.
Meet the people whose lives, choices and achievements shaped the journey.
Black towns, communities, institutions and places where history happened.
Moments that changed communities, movements, institutions and the nation.
In 1968 Shirley Chisholm became the first Black woman elected to the United States Congress. In 1972 she launched a campaign for the Democratic presidential nomination, breaking another political barrier.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
Society of Automotive Engineers standard SAE J1708 is a standard used for serial communications between ECUs on a heavy duty vehicle and also between a computer and the vehicle. With respect to Open System Interconnection model (OSI), J1708 defines the physical layer. Common higher layer protocols that operate on top of J1708 are SAE J1587 and SAE J1922. The protocol is maintained by SAE International.
The standard defines a 2-wire 18 gauge wire cable that can run up to 130 feet (40 m) and operates at 9600 bit/s. A message is composed of up to 21 characters, unless the engine is stopped and the vehicle is not moving in which case transmitters are allowed to exceed the 21 byte max message length. Messages start with a Message ID (MID) character and finish with a checksum at the end. Characters are transmitted in the common 8N1 format.
The hardware utilized are RS-485 transceivers wired for open collector operation through the use of a pullup and pulldown of the separate data lines. Transmission is accomplished by controlling the driver enable pin of the transceiver. This method allows multiple devices to share the bus without the need for a single master node. Collisions are avoided by monitoring the bus while transmitting the MID to ensure that another node has not simultaneously transmitted a MID with a higher priority.
SAE J1708, although still widely used, is replaced by SAE J1939 which is a CAN protocol.
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
Society of Automotive Engineers standard SAE J1708 is a standard used for serial communications between ECUs on a heavy duty vehicle and also between a computer and the vehicle. With respect to Open System Interconnection model (OSI), J1708 defines the physical layer. Common higher layer protocols that operate on top of J1708 are SAE J1587 and SAE J1922. The protocol is maintained by SAE International.
PJM Interconnection LLC (PJM) is a regional transmission organization (RTO) in the United States. It is part of the Eastern Interconnection grid operating an electric transmission system serving all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and the District of Columbia. PJM is the largest power grid operator in the United States, serving 67 million customers from Chicago to New Jersey. PJM, headquartered in Valley Forge, Pennsylvania, was the world's largest competitive wholesale electricity market until the development of the European Integrated Energy Market in the 2000s. More than 1,000 companies are members of PJM, which has 182 gigawatts of generating capacity. With 1,436 electric power generators and 88,333 miles (142,158 km) of transmission lines, PJM delivered over 800 terawatt-hours of electricity in 2024. Started in 1927, the pool was renamed the Pennsylvania-New Jersey-Maryland Interconnection (PJM) in 1956. The organization continues to integrate additional utility transmission systems into its operations. The Federal Energy Regulatory Commission (FERC) regulates PJM, and approves its open access transmission tariff for the wholesale electricity market. In 2026, PJM is anticipating future supply shortages due to expected 5% annual demand growth (compared to no growth from 2005-2020) from new data centers, combined with supply constraints from shutdowns of many generation plants for environmental or economic reasons, and the difficulty of timely permitting of new power plants.
The Open Systems Interconnection (OSI) model is a reference model published in 1984 by the International Organization for Standardization (ISO) that "provides a common basis for the coordination of standards development for the purpose of systems interconnection." In the OSI reference model, the components of a communication system are distinguished in seven abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application. The model describes communications from the physical implementation of transmitting bits across a transmission medium to the highest-level representation of data of a distributed application. Each layer has well-defined functions and semantics and serves a class of functionality to the layer above it and is served by the layer below it. Established, well-known communication protocols are decomposed in software development into the model's hierarchy of function calls. The Internet protocol suite as defined in RFC 1122 and RFC 1123 is a model of networking developed contemporaneously with the OSI model, and was funded primarily by the U.S. Department of Defense. It was the foundation for the development of the Internet. It assumed the presence of generic physical links and focused primarily on the software layers of communication, with a similar but much less rigorous structure than the OSI model. In comparison, several networking models have sought to create an intellectual framework for clarifying networking concepts and activities, but none have been as successful as the OSI reference model in becoming the standard model for discussing and teaching networking in the field of information technology. The model allows transparent communication through equivalent exchange of protocol data units (PDUs) between two parties, through what is known as peer-to-peer networking (also known as peer-to-peer communication). As a result, the OSI reference model has not only become an important piece among professionals and non-professionals alike, but also in all networking between one or many parties, due in large part to its commonly accepted user-friendly framework.
Intermediate System to Intermediate System (IS-IS, also written ISIS) is a link-state interior gateway protocol (IGP), typically deployed within a single autonomous system, and is used in large enterprise and service-provider networks to exchange routing information. The IS-IS protocol is defined in ISO/IEC 10589:2002 as an international standard in the Open Systems Interconnection (OSI) model. IS-IS operates by flooding link-state information through a network of routers. Each IS-IS router builds its own link-state database (LSDB) by collecting the flooded link-state information from other routers. Like Open Shortest Path First (OSPF), IS-IS uses Dijkstra's algorithm for computing the shortest paths through the network. Packets (datagrams) are then forwarded along the computed shortest paths to their destinations.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →The Greenwood District.