S-100 bus

E744086

The S-100 bus is an early microcomputer expansion bus standard, originally used in Altair 8800–era systems, that defined a 100-pin edge connector for modular CPU, memory, and peripheral cards.

All labels observed (5)

Label Occurrences
S-100 bus canonical 13
S-100 bus systems 2
Altair bus 1

How this entity was disambiguated

Statements (50)

Predicate Object
instanceOf computer bus standard
hardware interface
microcomputer expansion bus
addressBusWidth 16-bit (originally)
24-bit (later IEEE 696)
alsoKnownAs Altair bus
linked to: S-100 bus

S100 bus
linked to: S-100 bus
architecture parallel bus
connectorType edge connector
controlSignals DMA support (later)
interrupt lines
separate control lines for memory and I/O
dataBusWidth 16-bit (later IEEE 696)
8-bit (originally)
governedBy IEEE 696 standard
linked to: IEEE 696
historicalSignificance one of the first widely adopted microcomputer bus standards
influenced later microcomputer bus designs
introducedBy MITS
introducedInProduct Altair 8800
linked to: MITS Altair 8800
introducedYear 1975
marketRole enabled third-party hardware ecosystem for early microcomputers
numberOfPins 100
operatingSystems CP/M
CP/M-86 (on later 16-bit systems)
linked to: CP/M-86
popularIn 1970s
early 1980s
predecessorOf later proprietary PC expansion buses
regionOfPopularity Europe
United States
standardizedAs IEEE 696
standardizedYear 1979
supportedCPU Intel 8080
Intel 8085
Intel 8086 (later systems)
linked to: Intel 8086

Motorola 68000 (via adapter designs)
Zilog Z80
typicalCardFormFactor plug-in board with 100-pin edge connector
usedFor CPU cards
memory cards
microcomputer expansion
peripheral interface cards
usedIn Altair 8800
linked to: MITS Altair 8800

Cromemco systems
linked to: Cromemco

IMSAI 8080
NorthStar Horizon
Vector Graphic systems
linked to: Vector Graphic

various CP/M computers
voltageLevels +16 V
+8 V
±16 V (later variants)

How these facts were elicited

Referenced by (18)

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

Control Program for Microcomputers usedOn S-100 bus systems
linked to: S-100 bus
IMSAI 8080 busArchitecture S-100 bus
MP/M targetHardware S-100 bus systems
linked to: S-100 bus
S-100 bus alsoKnownAs S100 bus
linked to: S-100 bus
S-100 bus alsoKnownAs Altair bus
linked to: S-100 bus
Cromemco usedHardwareStandard S-100 bus
Cromemco busStandard S-100 bus
CompuPro usedBusArchitecture S-100 bus
Altair 8800 expansionBus S-100 bus
subject linked to: MITS
MITS associatedWith S-100 bus standard
linked to: S-100 bus