PCI Memory Resources, PCI Card, PCI Express Card

CHAPTER 4: Hardware Installation

To observe the resources assigned by Windows 95/98 for the adapter, click on Start, then Settings, then Control Panel, and then double-click on System. Click on the Device Manager Tab, then double-click on 5250 Emulation Adapters. There will be an entry for the 5250 PCI Adapter. Double-click on this entry and then select the Resources tab. The display will now show the 5250 PCI Adapter Card resources.

The resources can also be observed by executing the GETW95C.EXE program in the 5250CARD directory. The resource information passed from Windows 95/98 to the CEM5250.VXD device driver will be displayed.

PCI Memory Resources

The PCI specifications allow the PCI card to be assigned memory resources anywhere in the system memory. In most cases, the preferred memory location of the PCI card is in lower memory (C800h, CC00h, D800h) to remain compatible with legacy applications.

Some PC manufacturers have specifically reserved these memory locations for motherboard or ISA resources. This can cause a problem when the PC’s BIOS tries to assign a memory resource to the PCI card. Problems can include memory conflicts, failure to boot, and system crashes.

In order to resolve this problem, the PCI card and the PCI Express Card use the following methods.

PCI Card

The PCI Card can be programmed through software to function below and above one megabyte in memory. The utility to program the PCI Card is called PCISET.EXE and is found on disk 1 of the software diskettes. See Section 5.3 for details about the PCISET program.

PCI Express Card

The PCI Express card has an on-board jumper that allows the card to be configured for use above and below one megabyte in memory. See Figure 4-2for the location of this jumper.