SCSI disk interface software needed for Symbolics XL400

["Leslie A. Walko" <attila@FLASH.BELLCORE.COM>]

	Does anyone know of a SCSI driver for the XL400 machine? 
 
    Date: Mon, 7 Aug 89 15:27 EDT
    From: Reti@RIVERSIDE.SCRC.SYMBOLICS.COM

    SCSI disk drivers already exist in the Genera 7.4+ software; they
    work but are currently officially unsupported.

Thank you for your prompt reply!

We would be very happy with unsupported software for now.  (We can set
up automated backups to Unix boxes which run when the machine is idle.
At most, we loose the currently modified version of some file.)  So, if
you could point us to where the software is, we would like to take our
chances.

    The issues about attaching a random SCSI
    disk are 1) many don't permit sufficient flexibility to fit the
    Lispm constraints on block size (i.e. a disk block must be at least
    256 words long, or (* 5 256) = 1280 bytes and 

This suggests that there are *some* disks which do permit 1280 Bytes or
longer blocks.  Which ones are on this category?

    2) the performance is usually pretty bad compared with the
    equivalent ESDI disk. 

True, it is *pretty bad* relative to ESDI, but no worse than the *best*
performance using a SUN for example and certainly better than getting
the data from some Unix file server (which probably uses SCSI) accross
Ethernet.  The performance of SCSI is quite acceptable for many uses
--system source, rarely used files, mail collections, fonts, bitmaps,
etc.

Leslie Walko		attila@bellcore.com    201/829-4824