History (1977): Standards Accelerate Disk Drive Integration

This article comes from the Computer History Museum.

1977: Standards Accelerate Disk Drive Integration
Disk drive interfaces either become a standard or fail in the marketplace

Dal Allan, publisher of ENDL newsletter

Standardized hardware and software for connecting disk drives to other computer components expand the market and accelerate the adoption of new technology. Efforts began in 1977 to define Control Data Corporation’s SMD (Storage Module Drive) interface as a storage industry standard. Subsequently every new interface developed for disk drives either became a standard or failed in the marketplace.

The following dominate different market segments:

SCSI – The Shugart Associates Systems Interface (SASI) defined under the leadership of Larry Boucher who later founded Adaptec, was adopted as the Small Computer System Interface (SCSI) in 1982. Originally used as a universal peripheral interface, SCSI has grown into the high performance interface of choice for disk and tape as SAS (Serial Attached SCSI).

IDE – In 1985, Bill Frank at Western Digital wrote a specification to integrate the Host Bus Adapter (HBA) electronics onto the disk drive board of IBM’s PC AT computer. The IDE (Integrated Drive Electronics) interface quickly dominated the market for PC-attached disk drives. The proliferation of variations led to the AT-Attachment (ATA) project in 1989 and the ATAPI (ATA Packet Interface) in 1993.

Fibre Channel – Work on defining Fibre Channel started in 1988 to provide SCSI, IPI (Intelligent Peripheral Interface) and HIPPI (HIgh-Performance Parallel Interface) with a growth path to a switched 100MB/s serial interface. After Brocade Communications Systems introduced a packet switch championed by founder Kumar Malavalli, the rapid adoption of Storage Area Networks (SANs) changed how companies managed data storage.

The storage industry’s embrace of standards extends to the complementary specifications of form factor packaging, connectors, and transceivers. Efforts to simplify the integration of storage continue as a voluntary activity in several technical committees.