The above list does not imply a specific sequence of events. Following a command to a target to send data to the initiator and a receipt of a command complete status, the initiator could send another command or even send a message.<!--[[User:Kvng/RTH]]-->
==External connectors==
{{main article|SCSI connector}}
No version of the standard has ever specified what kind of [[SCSI connector|connector]] should be used. Specific types of connectors for parallel SCSI devices were developed by vendors over time. Connectors for serial SCSI devices have diversified into different families for each type of serial SCSI protocol. See the [[SCSI connector]] article for a more detailed description.
AlthoughOriginal parallel SCSI-1 devices typically used bulky [[Micromicro ribbon|Blue Ribbon]] Amphenol connectors, and SCSI-2 devices typically used [[D-subminiature|Mini-DMD50]] connectors,. itConnectors is not correctevolved to refer to these as "SCSIHigh-1" and "SCSI-2" connectors. One valid rule is that connectors for wide SCSI buses have more pins and wires than those for narrow SCSI buses. An Amphenol-50 orDensity (HD-50 connector is for narrow SCSI, while an Amphenol-68 or HD-68 connector is for wide SCSI. On some early devices, wide parallel SCSI buses used two or four connectors) and cablesmost whilerecently narrow[[Single SCSIConnector buses used only oneAttachment]].
Connectors for wide SCSI buses have more pins and wires than those for narrow SCSI buses; typically 50 pins for narrow SCSI and 68 pins for wide SCSI. On some early devices, wide parallel SCSI buses used two or four connectors and cables while narrow SCSI buses used only one.
The first parallel SCSI connectors were the Amphenol type. They then evolved through two main stages, High-Density (HD) and most recently [[Single Connector Attachment|SCA - 80 pin]].
With the HD connectors, a cable normally has male connectors while a SCSI device (e.g., host adapter, disk drive) has female. A female connector on a cable is meant to connect to another cable (for additional length or additional device connections).<!--[[User:Kvng/RTH]]-->
