Expansion Slots

Front 1

ISA

Back 1

Industry Standard Architecture
Speed: 8 MHZ
Data Bits: 8 & 16 bit
Use: Modems, 8-bit expansion cards

Front 2

MCA

Back 2

Micro Channel Architecture
Speed: 10 MHZ
Data Bits: 16 & 32 bit
Use: This bus is now obsolete

Front 3

EISA

Back 3

Extended Industry Standard Architecture
Speed: 8MHZ
Data Bits: 32 bit, but able to support 8 and 16 bit
Use: Specialty roles; mostly obsolete and being replaced by PCI slots

Front 4

VESA

Back 4

Viseo Electronics Standards Association
Speed: 33 MHZ
Data Bits: 32 bit
Use: Once used for faster video performance than the ISA bus, this bus has since become obsolete

Front 5

PCI

Back 5

Peripheral Component Interconnect
Speed: 33 MHz
Data Bits: 32 bit, 64 bit
Use: Audio and video cards, networking cards, modems, SCSI adapters and more. Not for use with serial or parallel ports.

Front 6

AGP

Back 6

Accelerated Graphics Port
Speed: 66 MHz
Data Bits: 32 bit
Use: Video adapter only