

                                STAC ELECTRONICS
                           TECHNICAL SUPPORT BULLETIN

  NUMBER:     009
  SUBJECT:    CACHE

  DATE:       May 24, 1991
  TIME:       3:00 PM

  SOURCE:         Engineering, Tech Support
  SUPERCEDES/
  SUPERCEDED BY:  
  RELEASE STATUS: Public

  TITLE:
      STACKER and disk-cache programs.

  OVERVIEW:
      While STACKER includes its own cache, the driver is compatible with other
      products that perform the same function.

      Norton's NCACHE and Microsoft WINDOWS' SMARTDRV.SYS are loaded from the
      CONFIG.SYS, usually before STACKER.  Other programs, such as PC-KWIK and
      PC-CACHE, load from the AUTOEXEC.BAT file, after STACKER.

  ISSUES/COMMENTS:
      1) Some cache programs (e.g., PC-CACHE, PC-KWIK) may report that a
      particular drive letter is not eligible for caching, but caching proceeds
      normally.

      2) When multiple cache programs are operating, disk reads/writes may have
      unpredictable results.  Use of memory may also be negatively impacted.


  RECOMMENDED ACTIONS:
      1) Alter the settings for the cache so that the uncompressed, host drive
      is cached.  This will, by extension, cache any STACKER volumes residing
      on it.  (The PC-KWIK message can be avoided by excluding the STACKER
      volume when the cache program is invoked.  Consult PC-KWIK documentation
      for the appropriate parameter.)

      2) If a commercial cache program is running, specify a STACKER cache of 0
      bytes (/M=0)