HP 7958 Disc Drive

The 7958A was a modular 130MB hard disc drive connected primarily to 300 Series machines. It had an HP-IB interface with an average seek time of 29ms and a data transfer rate of 1.25 MB per second. The 7958B was introduced in 1988 with a storage capacity of 152MB and average seek time of 17ms. The 7958S was introduced in 1989 with a SCSI interface, 17.5ms average seek time, 1.5 MB per second data transfer rate, and 161MB storage capacity.