IBMCACHE.SYS Will Not Load If HIMEM.SYS Is Loaded (71989)

The information in this article applies to:
    Microsoft MS-DOS operating system 4.0
    Microsoft MS-DOS operating system 4.01
    Microsoft MS-DOS operating system 5.0

This article was previously published under Q71989


The disk caching program IBMCACHE.SYS version 1.00 will not load if HIMEM.SYS is loaded. When the cache device driver is loaded with DOS high, the following error message appears:

Allocating Cache Buffers...Not enough space to allocate Cache buffers
This problem occurs because IBMCACHE.SYS tries to allocate extended memory via the interrupt 15 (or INT 15) interface. As specified by XMS 2.0, HIMEM.SYS allocates all extended memory to itself via INT 15 to provide XMS memory.

There are three workarounds to this problem:

    Do not load HIMEM.SYS.
    In MS-DOS version 5.0, load HIMEM.SYS with the following switch:
          DEVICE=HIMEM.SYS /INT15=xxxx
    This switch allocates the specified amount of extended memory, in kilobytes, for the interrupt 15h interface. To ensure that enough memory is available, add 64 to the value you want to specify for xxxx. Valid values range from 64 through 65535. For more information on the /INT15 switch, refer to the version 5.0 "Microsoft MS-DOS User's Guide and Reference."

Modification Type: Major Last Reviewed: 10/15/2003
Keywords: KB71989