IBM 6275 - PC 300 GL, Technical Information Manual

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Chapter 2. System-Board Features
Flash EEPROM
The system board uses an 8 Mb flash electrically-erasable, programmable, read-only memory (EEPROM)
to store the basic input/output system (BIOS), video BIOS, IBM logo, Configuration/Setup Utility, and Plug
and Play data.
If necessary, the EEPROM can be easily updated using a stand alone utility program that is available on a
3.5-inch diskette.
Riser Card
The system board uses a riser card to route PCI and ISA bus signals to the expansion connectors. Each
ISA-expansion connector is 16 bits, and each PCI-expansion connector is 32 bits. PCI-expansion
connectors support the 32 bit 5, V dc, local-bus signalling environment that is defined in
PCI Local Bus
Specification 2.1. The ISA bus is buffered to provide sufficient drive for the ISA-expansion connectors,
assuming two low-power Schottky (LS) loads per slot.
The system board uses one of two riser cards. The two riser cards provide different configurations of PCI
and ISA connectors and are representative of the different mechanical sizes. The following figure
summarizes the characteristics of the two riser cards.
* Indicates full size adapter slots.
For information on the connector pin assignments, see “ISA Connectors” on page 54 and “PCI
Connectors” on page 56.
Figure 4. Riser Card Characteristics
Expansion Slots 4x4 Riser Card 6x6 Riser Card
Shared ISA/PCI 1* 0
Dedicated ISA 1* 3*
Dedicated PCI 2 3*
Chapter 2. System Board Features
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