National Instruments VXI-1394 - Manual (Page 58)

Appendix D Common Questions
© National Instruments Corporation D-5 VXI-1394 User Manual for Windows
What is shared memory and dual-ported memory?
These terms refer to a block of memory that is accessible to both a client
and a server. The memory block operates as a message buffer for
communications. Shared memory is applicable only if you are using either
A24 or A32 address space.