Honeywell 6000 Series Reference Manual page 13

COMPONENT FUNCTIONS
SECTION II
FUNCTIONAL DESCRIPTION
The Disk Storage Subsystem may be configured in many different ways to obtain data
availability and throughput requirements. Versatility, especially adaptability to new require-
ments' is significantly inc reased by the use of a microprogrammed peripheral control as the
disk storage control (DSC) for the subsystem. The disk storage units (disk pack drives and
disk packs) communicate with the DSC across a radial interface that permits a DSU to be
reInoved from service without interfering with the operation of other DSU's in the subsystem.
Four of various subsystem configurations that may be used in a computer system are
shown in Figures 2 -1 through 2 -4. The abbreviations used are:
ADE - Additional Drive Electronics
CCA or CA - Control Adapter
DCA Disk Control Adapter
DCX Dual Control Crossbar (includes associated cables and
additional EDE electronics)
DSC - Disk Storage Control (refers to the complete control)
DSS Disk Storage Subsystem
DSU Disk Storage Unit (refers to the DSU190 and DSU190B
Disk Storage Units unless noted otherwise)
EDAC Error Detection and Correction
EDE Extended Drive Electronics
EUS External User System (refers to any Series 6000 Central
System or DATANET 355 Front-End Network Processor)
IDCW - Instruction Data Control Word
LA - Link Adapter
OPl - Operational In (a status line from the device to the controller
indicating the operational status of the device)
Z -1 DB37