For example, we may have 4 gigabytes of RAM on one machine, and 16 gigabytes on another machine. Devices that may have configurable parameters or may be upgraded or changed from time to time, can’t actually be handled by the BIOS alone because the presence of the device or the quantities or parameters may change from system to system.
We don’t have to set anything in the BIOS to support these devices. These parameters don’t change so nothing has to be changed in the programming that allows the CPU to communicate with that given device. Devices that have no configurable parameters can be handled by the BIOS alone. And we have custom devices that may or may not be present in any given system. We have devices that have configurable parameters or that are likely to be changed from time to time. We have devices that have no configurable parameters and aren’t likely to ever be replaced. Device Categoriesĭevices that are connected to or are part of the motherboard can be categorized into three different categories. Updating the BIOS (called flashing the BIOS) makes new features available, such as allowing the BIOS to recognize newer hardware devices. Some motherboards have two BIOS chips, one for the main BIOS and a second for a backup. BIOS is not rewritable and it is an example of firmware. We should check for BIOS updates from manufacturers frequently. The CPU can read information from the ROM chip the same way it reads information from RAM. Most of the ROM chips that we use in a PC system for the BIOS are about 64K in size though there is 384k address space available for the BIOS to use. We often refer to BIOS as the BIOS chip, but BIOS is not really the chip itself, it’s the software inside that’s really the BIOS. BIOSīIOS is the collection of programs contained in the ROM chip. Those programs stored on the ROM Chip are collectively referred to as the Basic Input/Output Services or BIOS chip.
These devices include the keyboard, disk drives, memory, etc. ROM chips that are installed on the motherboard contain programs that were burned into that ROM, that allow the CPU to communicate the with various devices attached to the motherboard. In contrast to ROM, a RAM chip loses it’s contents when the PC’s turned off. ROM stands for Read Only Memory, and this kind of chip retains it’s contents even if the system is powered off. To enable our CPU to communicate with other devices on our motherboard, we implement a special chip on the motherboard called a ROM chip. Key terms: device, chip, cpu, memory, parameter, motherboard, battery, post, load, data, power, address, software, firmware Objectives: Learn the difference between BIOS and CMOS.
0 kommentar(er)
