Serial presence detect use of SIMMs with "parallel" presence detect (more commonly called simply "presence detect" or PD). Some of this equipment uses non-standard PD coding, IBM computers and Hewlett-Packard LaserJet and other printers in particular. Serial presence detect In computing, serial presence detect (SPD) is a standardized way to automatically access information about a memory module. Earlier 72-pin SIMMs included five pins that provided five bits of "parallel presence detect" (PPD) data, but the 168-pin DIMM standard changed to a serial presence detect to encode much more information. When an ordinary modern computer is turned on, it starts by doing a power-on
Parallel and counter parallel Parallel and counter parallel In music, a parallel chord (relative chord, German: "Parallelklang") is an auxiliary chord derived from one of the primary triads and sharing its function: subdominant parallel, dominant parallel, and tonic parallel. The term is derived from German theory and the writings of Hugo Riemann (see: Riemannian theory). For example, the major and and minor and . The parallel chord (but "not" the counter parallel chord) of a major chord will always be the minor chord whose root is a minor third "down" from the major chord's root, inversely the parallel chord of a minor chord will