EISA Configuration Chip (AIC-575)The host adapter provides a number of options which may be programmed at configu-ration time. They are summarized below:• AHA-1540 base port address• Bus on time after preempt• Interrupt definition and selection• Synchronous negotiation enable/disable per target• Disconnection enable/disable per target• Boot drive identification for DOS• BIOS enable, location, and optionsThe following versions of the ASW-1400 family of software managers support thesefeatures:• ASW-1410, v3.0 and later• ASW-1420, v1.3 and later• ASW-1440, v3.0 and later• ASW-1450, v1.0 and laterBMIC Bus Interface Chip (82355)This highly integrated ASIC device from Intel controls and interfaces to the EISAbus. It implements the following main functional blocks:• 32-bit bus interface• Adapter FIFO interface• EISA bus protocol logicFloppy Disk Controller (AHA-1742A Only)This is implemented by a 82077A single-chip floppy disk drive controller. All drivecontrol signals are fully decoded and have 40 mA drive buffers with selectable polar-ity. Signals returned from the drive are sent through on-chip input buffer with hys-teresis for noise immunity. The integrated analog data separator needs no externalcompensation yet allows for a wide motor speed variation with exceptionally low softerror rates. The microprocessor interface has a 12 mA drive buffer on the data busplus 100% hardware register compatibility for standard systems. The 16-byte FIFOwith programmable thresholds is extremely useful in multimaster systems, oradaptec AHA-1740A/1742A/17442-4
