[comp.sys.ibm.pc] About SCSI

neese@cpedev.UUCP (02/02/88)

Let's talk SCSI.......

  Adaptec has announced the AHA-1540 AT SCSI Host Adapter.  I'd like
to talk a little about it.  Here's the bullets:

. High Performace First Party DMA with programmable data rates of up to
  10 MB/sec.
. 16 and 8 bit transfers
. Even or odd starting address transfers
. Maximum sychronous SCSI transfer rate of 5.0MB/sec.
. Asychronous and Sychronous peripherals supported simultaneously
. Programmable AT bus burst transfer on/off times
. Jumper selectable DMA channel for bus arbitration (0,5,6,7)
. Jumper selectable interrupt channels (9,10,11,12,14,15)
. True multi-threaded operation supporting up to 255 tasks simultaneously
. Programmable mailbox architecture
. BIOS for AT hard disk emulation.
. Jumper selectable I/O port address
. Internal and external SCSI connectors

  That's the bullets.  Target retail prices between $300.00 and $350.00.
Basically, its the highest performance I/O adapter in its class.  At the
BIOS level I have measured real data through puts of 2.0MB/sec.  As opposed
to the 247Kb/sec for ST-506 and 730KB/sec to 1.0MB/sec for ESDI.  The
beautiful thing about this performance is that it is independent of the
CPU.  You can have this performance in a 8MHZ 286AT or a 16MHZ 386 box due
to the on-board DMA.


						Roy Neese
					UUCP @	ihnp4!sys1!cpe!neese