Motherboard BIOS and Setup Utility

3.14.10.3ISA Shared Memory Size

Sets a range of memory addresses that will be directed to the ISA bus rather than on-board memory. The options are:

Disabled (default)

16 KB

32 KB

48 KB

64 KB

80 KB

96 KB

If this is set to Disabled, the ISA Shared Memory Base Address (described below) will not be visible.

This field should be set to Enabled only when a non Plug and Play ISA card (legacy card) that requires non-ROM memory space is used. LAN cards that have on-board memory buffers are one example of this; video capture cards that have video buffer memory are another.

By default, allocation of upper memory is as follows: memory from C0000-C7FFF is automatically shadowed. (This memory range is typically reserved for video BIOS.) Memory from C8000-DFFFFh is initially unshadowed. The BIOS scans this range for any ISA expansion card BIOS that may be present and notes the location and size. The BIOS will then autoconfigure the PCI and Plug and Play devices, shadowing the ROM requirements (other than video) into the area above E0000h until that area is full. It will then assign additional PCI and Plug and Play expansion cards to the area between C8000h and DFFFFh. If an ISA legacy card has non-ROM memory requirements, the autoconfigure routine may write into an area that is needed by the ISA expansion card. The ISA Shared Memory Size parameter signifies the autoconfigure routine that this block of memory is reserved and should not be shadowed.

Shadowing is a technique that copies a block of memory from an add-in card’s ROM to the same address in system memory. This provides faster access and achieves higher performance. By default, all upper memory is shadowed.

3.14.10.4ISA Shared Memory Base Address

Sets the base address for the ISA Shared Memory. The options are:

C8000h (default)

CC000h

D0000h

D4000h

D8000h

DC000h

This setting could affect the ISA Shared Memory Size item. The value entered in the ISA Shared Memory Size item cannot extend to the E0000h address.

For example, if a size of 64K is selected, options D4000h, D8000h, and DC000h are not available. If the ISA Shared Memory Size is set to Disabled, this field will not appear.

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Intel AP440FX specifications ISA Shared Memory Size, ISA Shared Memory Base Address, ∙ C8000h default

AP440FX specifications

The Intel AP440FX is a pivotal motherboard that was released in the late 1990s, designed to support the Intel Pentium II and Pentium III processors. Known for its robust performance and versatile functionalities, the AP440FX became a popular choice among computer enthusiasts and system builders during its time.

One of the defining features of the Intel AP440FX is its support for the Intel 440FX chipset. This chipset provided improved system performance through its use of a 66 MHz front-side bus, which allowed for faster data transfer between the CPU and the memory. The motherboard was equipped with two DIMM slots capable of supporting a maximum of 512 MB of SDRAM, providing users with the flexibility to choose the amount of memory they required for their applications.

Another notable characteristic of the AP440FX motherboard is its integrated support for various peripheral interfaces. It comes equipped with multiple ISA and PCI slots, allowing users to expand their system capabilities through the addition of various cards. The presence of two USB ports, which were relatively new at the time of its release, gave users access to a wider range of peripherals and external devices.

The Intel AP440FX also features an integrated IDE controller, enabling connection for hard drives and optical drives without the need for additional controller cards. This integrated solution simplified storage management for users and contributed to the overall efficiency of the system. The motherboard also supported SCSI through optional daughter cards, catering to users who required high-speed data transfer and reliable disk storage solutions.

Moreover, the AP440FX was designed with future upgrades in mind. Its BIOS supported plug-and-play installations, allowing users to easily configure new hardware components without extensive troubleshooting. Additionally, the ATX form factor of the motherboard contributed to its compatibility with a wide range of cases and power supplies.

In terms of power management, the Intel AP440FX incorporated advanced features such as ACPI (Advanced Configuration and Power Interface), which allowed for better power efficiency and management of power states. This feature was particularly beneficial for users looking to reduce energy consumption and improve the overall longevity of their systems.

All in all, the Intel AP440FX represented a significant advancement in motherboard technology during its era. Its combination of robust performance, upgradeability, and support for new technologies made it a popular choice for users looking to build powerful and efficient computing systems.