FIX: Phar Lap err 58 Running MASM From Read-Only Drive

The information in this article applies to:

• Microsoft Macro Assembler for MS-DOS, version 6.1

SYMPTOMS

An attempt to run the Microsoft Macro Assembler (MASM) version 6.1 fails and MASM generates the following message:

   Phar Lap err 58: Can't create VM swap file of size 0 in directory

CAUSE

MASM is installed on a read-only drive, possibly a network drive. The error occurs because the DOSXNT DOS extender attempts to create a virtual memory swap file on the drive DOSXNT runs from when the operating system does not support virtual memory.

RESOLUTION

To work around this problem, you can run DOSXNT on a read/write drive listed in your PATH MS-DOS environment variable. In addition, you can specify one of the following two environment variable settings to prevent DOSXNT from attempting to create a swap file on the read-only network drive:

• Set the DOSX environment variable to prevent DOSXNT from using any virtual memory. Edit your AUTOEXEC.BAT file to include the following:

        set dosx=-novm
  

• Set the DOSX environment variable to specify where DOSXNT creates the virtual memory swap file. Edit your AUTOEXEC.BAT file to include the following:

        set dosx=-swapdir <path>
  

  where <path> specifies the drive and directory on which to create the temporary swap file.

STATUS

Microsoft has confirmed this to be a problem in MASM version 6.1. This problem was corrected in MASM version 6.1a.