## Virtual Device Driver Reference for OS/2

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### DOS Session Creation

When a DOS session is created, the virtual BIOS device driver is responsible for allocating and initializing the following areas in the DOS session's address space with the respective values from physical memory:

Interrupt Vector Table
BIOS data area
DOS communications area
Extended BIOS data area (on a PS/2 personal computer).

The virtual BIOS device driver is also responsible for mapping the system ROM and adapter ROM into the address space of the DOS session. The per-DOS session copy of the POS registers is initialized at this time.