PIO | Programmed Input/Output. A way the CPU can transfer data to and from |
| memory using the computer’s I/O ports. PIO is usually faster than DMA, |
| but requires CPU time. |
Port Address | Also Port Number. The address through which commands are sent to a |
| host adapter board. This address is assigned by the PCI bus. |
Port Number | See Port Address. |
Queue Tags | A way to keep track of multiple commands that allow for increased |
| throughput on the SCSI bus. |
RAM | Random Access Memory. The computer’s primary working memory in |
| which program instructions and data are stored and are accessible to the |
| CPU. Information can be written to and read from RAM. The contents of |
| RAM are lost when the computer is turned off. |
RISC Core | LSI Logic SCSI chips contain a RISC (Reduced Instruction Set |
| Computer) processor, programmed through microcode scripts. |
ROM | Read Only Memory. Memory from which information can be read but not |
| changed. The contents of ROM are not erased when the computer is |
| turned off. |
SCAM | SCSI Configured AutoMatically. A method to automatically allocate SCSI |
| IDs using software when SCAM compliant SCSI devices are attached. |
SCSI | Small Computer System Interface. A specification for a |
| peripheral bus and command set. The original standard is referred to as |
| |
The current SCSI specification which adds features to the original | |
| |
| The SCSI specification which adds features to the |
SCSI Bus | A host adapter and one or more SCSI peripherals connected by cables |
| in a linear chain configuration. The host adapter may exist anywhere on |
| the chain, allowing connection of both internal and external SCSI |
| devices. A system may have more than one SCSI bus by using multiple |
| host adapters. |