IV. BIOS SOFTWARE

DMA x Used By ISA (No/ICU)

These fields indicate whether or not the displayed DMA channel for each field is being used by a legacy (non-PnP) ISA card. Available options include: No/ICU and Yes. The first option, the default setting, indicates either that the displayed DMA channel is not used or an ICU is being used to determine if an ISA card is using that channel. If you install a legacy ISA card that requires a unique DMA channel, and you are not using an ICU, you must set the field for that channel to Yes.

ISA MEM Block BASE (No/ICU)

This field allows you to set the base address and block size of a legacy ISA card that uses any memory segment within the C800H and DFFFH address range. If you have such a card, and you are not using an ICU to specify its address range, select a base address from the six available options; the ISA MEM Block SIZE field will then appear for selecting the block size. If you have more than one legacy ISA card in your system that requires to use this address range, you can increase the block size to either 8K, 16K, 32K, or 64K. If you are using an ICU to accomplish this task, leave ISA MEM Block BASE to its default setting of No/ICU.

SYMBIOS SCSI BIOS (Auto)

Auto allows the motherboard’s BIOS to detect whether you have a Symbios SCSI card. If a Symbios SCSI card is detected, the motherboard’s Symbios BIOS will be enabled; if no Symbios SCSI card is detected, the onboard Symbios SCSI BIOS will be disabled. Disabled will disable the motherboard’s Symbios SCSI BIOS so that the BIOS on an external Symbios SCSI card can be used. (If your Symbios SCSI card does not have a BIOS, the Symbios SCSI card will not function.)

USB Function (Disabled)

This motherboard supports Universal Serial Bus (USB) devices. Set to Enabled if you want to use USB devices. Your system must support USB function. The default setting is Disabled.

USB IRQ (Auto)

This field allows you to reserve an IRQ# (5, 7, 9, 10, 11, 12, 14, or 15) for the USB to work. Auto assigns an IRQ# automatically to your USB device. If you are not using a USB device, you may disable this feature by setting it to NA to save an extra IRQ# for other devices or expansion cards.

VGA BIOS Sequence (PCI/AGP)

If your computer has both PCI and AGP VGA cards, this field allows you to select which of the cards will act as your primary card. The default, PCI/AGP, allows your PCI card to take precedent when detected. AGP/PCI uses the AGP card as your primary card.

Plug & Play/PCI

IV. BIOS

ASUS P5A User’s Manual

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