### Memory Window Size and Starting Addresses

#### PCI Adapters

The memory starting address is determined by the PCI BIOS. No switches or jumpers are required to change these parameters.

Digi PCI adapters require 4 Megabytes of unused memory address space in your computer. This is typically allocated from the third or fourth gigabyte in your computer's memory map (it can, however, be mapped into any free region above the 1 Megabyte boundary, depending on your operating system).

#### ISA Adapters

The memory window size and starting address are programmed into the adapter by the device driver. No switches or jumpers are required to change these parameters.

The Digi Xe ISA adapters require 8K bytes of unused memory address space in your computer, and the other Digi adapters require 32K bytes. This is typically allocated from the area between 0C0000h and 0EFFFFh in your computer's memory map (it can, however, be mapped into any free region in the first sixteen megabytes of address space, depending on your operating system).

When deciding on a memory start address, keep in mind that the adapter may have to coexist with a number of other devices which also require memory address space. You may have to try a number of different starting addresses before you find a free area.

The starting addresses for 32K windows between 0C0000h and 0EFFFFh are 0C0000h, 0C8000h, 0D0000h, 0D8000h, 0E0000h and 0E8000h.

NOTE--If you are installing two or more Digi adapters, they may all share the same starting memory address.

You can use Digi's Memory Map utility to find free memory addresses. For information, see:

Using Digi's Memory Map Utility for ISA Adapters

Otherwise, if you don't know what areas in this region are free, you'll have to use trial and error to find an available 32K window.

A good sequence to try is:

- 0D0000h

- 0D8000h,

- 0C8000h

- 0C0000h.

If these don't work, try some of the addresses in the 0E0000h column (if your computer has Extended BIOS functions, this area may not be available).

If your system has monochrome graphics (e.g. Hercules), you may be able to use addresses in the 0A0000h-0AFFFFh range.

If your system has 512K of base memory (memory below 1 megabyte), instead of the usual 640K, you may be able to use addresses between 080000h and 09FFFFh.

Device | Addresses
VGA | A0000-C7FFF
Shadow RAM | Possibly anywhere. Check system BIOS setup.
SCSI Controller | DC000-DA000. Check controller documentation.
Network Interface | Check network interface controller documentation.

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