Description - IBM 5-1/4" Diskette Drive Adapter Hardware Reference Manual

Description
The IBM 5-1/4" Diskette Drive Adapter fits into one of the
expansion slots in the system unit. It is connected to one or two
diskette drives through an internal, daisy-chained flat cable. The
adapter has a connector at the other end that extends through the
rear panel of the system unit. This connector has signals for two
additional external diskette drives; thus, the 5-1/4 inch diskette
drive adapter can attach four 5-1/4 inch drives - two internal
and two external.
The adapter is designed for double-density, MFM-coded, diskette
drives and uses write precompensation with an analog phase-lock
loop for clock and data recovery. The adapter is a
general-purpose device using the
NEe fLPD765
or equivalent
controller. Therefore, the diskette drive parameters are
programmable. In addition, the attachment supports the diskette
drive's write-protect feature. The adapter is buffered on the I/O
bus and uses the system board's direct memory access (DMA) for
record data transfers. An interrupt level also is used to indicate
when an operation is complete and that a status condition requires
microprocessor attention.
In general, the 5-1/4 inch diskette drive adapter presents a
high-level command interface to software I/O drivers.
Diskette Adapter 1