Q-bus

E697042

Q-bus is a computer bus architecture developed by Digital Equipment Corporation for its PDP-11 and early VAX systems, providing a cost-effective, multiplexed alternative to the earlier Unibus.

All labels observed (1)

Label Occurrences
Q-bus canonical 6

How this entity was disambiguated

Statements (46)

Predicate Object
instanceOf computer bus architecture
system bus
addressSpaceType shared address and data lines
architectureFamily DEC bus architectures
belongsTo PDP-11 architecture ecosystem
linked to: PDP-11

VAX architecture ecosystem
compatibleWith various DEC peripheral controllers
designedFor PDP-11 minicomputers
linked to: PDP-11

low-cost system configurations
minicomputers
developer Digital Equipment Corporation
electricalType parallel bus
hasAdvantageOver Unibus in board count reduction
Unibus in cost
Unibus in wiring complexity reduction
hasCharacteristic cost-effective design
multiplexed bus
hasFeature arbitration for bus mastership
memory-mapped I/O
vector interrupts
hasNameVariant QBUS
introducedBy Digital Equipment Corporation
isAlternativeTo Unibus
manufacturer Digital Equipment Corporation
marketRole lower-cost alternative to Unibus-based systems
replaced Unibus
signalType multiplexed address/data lines
supports 16-bit data paths in many implementations
DMA transfers
I/O device connections
byte and word data transfers
extended addressing in later implementations
interrupt handling
memory transfers
multiple bus masters
topology backplane bus
usedDuring 1980s
early 1990s
late 1970s
usedFor connecting CPU, memory, and peripherals
expansion of PDP-11 and VAX systems via plug-in cards
usedIn MicroVAX systems
linked to: MicroVAX

PDP-11
VAX
early VAX systems
embedded and industrial PDP-11 systems

How these facts were elicited

Referenced by (6)

Full triples — surface form annotated when it differs from this entity's canonical label.

PDP-11 hasBusArchitecture Q-bus
Gordon Bell notableWork Q-bus
Unibus influenced Q-bus
Unibus replacedBy Q-bus
UNIBUS replacedBy Q-bus