Dat klopt ik heb het zelfde probleem gehad met meer dan 512Mb werkte bij mij de dosbox niet meer
http://support.microsoft.com/support/kb/articles/Q253/9/12.ASP?LN=EN-US&SD=gn&FR=0&qry=dos%20memory%20&rnk=23&src=DHCS_MSPSS_gn_SRCH&SPR=W98SE
CAUSE
The Windows 32-bit protected-mode cache driver (Vcache) determines the maximum cache size based on the amount of RAM that is present when Windows starts. Vcache then reserves enough memory addresses to permit it to access a cache of the maximum size so that it can increase the cache to that size if needed. These addresses are allocated in a range of virtual addresses from 0xC0000000 through 0xFFFFFFFF (3 to 4 gigabytes) known as the system arena.
On computers with large amounts of RAM, the maximum cache size can be large enough that Vcache consumes all of the addresses in the system arena, leaving no virtual memory addresses available for other functions such as opening an MS-DOS prompt (creating a new virtual machine).
WORKAROUND
To work around this problem, use one of the following methods:
Use the MaxFileCache setting in the System.ini file to reduce the maximum amount of memory that Vcache uses to 512 megabytes (524,288 KB) or less.
For additional information about how to use the MaxFileCache setting, click the article number below to view the article in the Microsoft Knowledge Base: