

                                STAC ELECTRONICS
                           TECHNICAL SUPPORT BULLETIN

  NUMBER:     006
  SUBJECT:    LOADHI

  DATE:       July 9, 1991
  TIME:       12:47 PM

  SOURCE:         Tech Support, Engineering, User's Manual
  SUPERCEDES/
  SUPERCEDED BY:  
  RELEASE STATUS: Public

  TITLE:
      Loading STACKER into high memory.

  OVERVIEW:
      To conserve base memory, it is possible to load the STACKER driver into
      high memory (between 640K and 1024K) on systems with 80286 chips and
      higher.  Appropriate memory management software (QRAM, MOVE'EM, QEMM386,
      386MAX) and hardware are needed.  Loading high on an 80286 machine
      requires hardware support for Expanded Memory Specification (EMS) 4.0
      (see User's Manual, "Loading STACKER into High Memory").

      Note: For loading high using MS-DOS 5.0's DEVICEHIGH, see TECH015.DOC,
      "Loading STACKER into upper memory with MS-DOS 5.0".

  ISSUES/COMMENTS:
      Potential problems with loading high are:
      -crowding in high memory, resulting in disk-read errors;
      -erratic behavior of memory-intensive programs;
      -exclude-phrases omitted from the memory manager device line (STACKER
          coprocessor version only);
      -load-high driver not invoked in STACKER.COM device driver line;
      -STACKER cache (/M=xx) specified at excessive size;
      -insufficiently large block of contiguous memory between 640K and 1024K.

  RECOMMENDED ACTIONS:
      1) Consult documentation for memory manager to verify syntax in
      CONFIG.SYS.  (User's Manual, page 33, shows examples of modification to
      STACKER line only.)

      2) If applicable, edit load-high driver line to exclude range used by
      coprocessor card (see User's Manual, "Re-enabling Memory Managers").
      Note that the correct syntax for the AT&T 6300's AEMM.SYS is /X=addr-
      addr.

      3) Verify syntax of load-high statement in STACKER.COM device driver line
      (see User's Manual, "Loading STACKER into High Memory").

      4) Reduce size of STACKER disk cache (/M=xx switch in STACKER.COM device
      driver line).

      5) To verify load-high status, use a memory-mapping utility such as
      Quarterdeck's MANIFEST.  If Interrupts 25 and 26 are at a segment value
      above A000, then STACKER is loaded high.