General description

The iSBC 214 multi-peripheral controller provides MUL TIBUS systems (8-bit and 16-bit data paths) with an interface for Winchester disk drives, flexible diskette drives, and streaming tape drives. A maximum of ten peripheral devices can interface with one board in the following configuration: two 5.25-inch Winchester disk drives, four 5.25-inch flexible diskette drives, and four lt4-inch streaming tape drives.

The iSBC 214 controller board emulates the iSBC 215G Winchester controller board communications protocol for interfacing the Winchester drives. The iSBX-217C and iSBX-218A MULTIMODULE® communications protocol is emulated for the tape drive and flexible disk drive interfaces. The Intel 80186 microprocessor serves as the controller’s CPU. The Intel 80186 features direct memory access (DMA) and uses a dual-bus architecture to maximize data transfer between the host memory and attached peripheral devices. Each peripheral device interface has a dedicated on-board VLSI controller to perform the data I/O functions requested by the host system.

The iSBC 214 controller increases the peripheral storage device control capabilities of Intel’s micro-systems. It uses VLSI technology for device interface control rather than MULTIMODULES. The following list briefly describes some of the major features of the iSBC 214 controller:

  • Supports the ST506/412 interface for one or two 5.25-inch Winchester drives
  • Supports the SA450 / 460 interface for up to four 5.25-inch flexible disk drives
  • Supports the QIC-2 interface for up to four lt4-inch Streaming Tape Drives
  • Supports 24-bit MUL TIBUS addressing
  • Emulates iSBC 215G controller I/O Parameter Block communications protocol (with or without the iSBX 217C and iSBX 218A MULTI MODULES)
  • Supports overlapped seek operations
  • Performs retry, Error Checking, and Correcting operations on Winchester drive data transfers
  • Software selectable bytes per sector, sectors per track, and tracks per surface for Winchester and flexible disk drives
  • Provides on-board power-up diagnostics

Electronics diagrams


The iSBC-214 controller can interface to one or two ST506/412 Winchester 5.25-inch disk drives. The Winchester physical interface consists of one 34-pin, right angle connector which handles a single control cable and two 20-pin, right angle connectors that mate with the Winchester data cables (one for each drive). The single control cable is connected in daisy chain manner to both drives.


The iSBC-214 controller can interface a maximum of four 5.25-inch flexible disk drives. To select 5.25-inch flexible disk drives, the user may jumper certain stake pins on the board. The flexible disk physical interface consists of a single 34-pin right-angle connector which mates to the drive’s data/control cable. Note that flexible diskettes formatted using an iSBC-215G controller with an iSBX-218A MULTIMODULE are compatible with the iSBC-214 controller as long as the data encoding technique is the same (FM or MFM).


The iSBC-214 board can interface up to four QIC-2 standard streaming tape drives. All standard commands in the QIC-2 interface are supported by the iSBC-214 board. The QIC-2 physical interface on the board consists of a single 50-pin rightangle connector. The QIC-2 control signal cable mates with this header; additional drives are daisy-chained off the control cable.