AHA-1740A/1742A/1744 Product FeaturesEISA FeaturesThe AHA-1740A/1742A/1744 is a full-performance EISA board offering the highestperformance available across the bus. It takes advantage of first-party DMA opera-tions, also known as bus mastering, which allow data transfers to proceed at highdata rates without system processor intervention. The main EISA functions whichcome standard on the board include:• Auto Configuration Support• High-performance Bus Master transfers with burst cycles which provide adata rate of 33 MBytes/second• 32-bit data path• 32-bit address space• Even or odd starting address and byte count handling• 1K FIFO for efficient data transfer• Interrupts enabled/disabled through I/O port write• Interrupts configurable for either edge or level trigger• Dual Control Interface, AHA-1540 family-compatible (Standard Mode) orEISA-SCB compatible (Enhanced Mode)SCSI FeaturesAdaptec has long been a supplier of leading edge SCSI products and the AHA-1740A/1742A/1744 is no exception. The board uses industry-standard protocol ICswhich fully comply with the 1990 ANSI SCSI specification, including:• Maximum synchronous SCSI transfer rate of 10.0 MBytes/second (Fast SCSI)• Asynchronous and synchronous peripherals supported simultaneously• Disable synchronous negotiation independently on each target as a configura-tion option• Disable disconnection independently on each target as a configuration option• Supports Modify Data Pointer message (Zero Latency Reads)• High-density SCSI-2 connector• Non-destructive current limit on terminator power supplyadaptec AHA-1740A/1742A/17441- 2
