Computer Architecture - Hardware - Lessons 1-2 - Eric Vanderburg

1. Computer Architecture:
Core Hardware
Chapter 1-2
Eric Vanderburg

2. Hardware
• Hardware & Software are soulmates
• Device Drivers
– 16 bit real mode (DOS, 9x)
– 32 bit protected mode (9x, Me, NT, 2000,
XP)
– 64 bit
• BIOS (Basic Input Output System)
– System BIOS – Controls basic devices
(FDD/Keyboard/Ports)
– Startup BIOS – Boots the computer
– CMOS setup – Allows changes to be
made to the startup BIOS.

3. Our toolkit so far
• What is in it?

4. Toolkit
• Crossover cable
• Boot CD
• Password recovery CD
• Screwdriver & other basic tools
• Flashlight
• Portable hard drive unit
• USB Flash drive

5. Resources
• IRQ (Interrupt Request) – ask for
attention
• I/O Address – where a device listens
• Memory Address
• DMA (Direct Memory Access)
channel

6. IRQs
IRQ Device IRQ Device
0 System Timer 8 Real Time Clock
1 Keyboard 9 Available
2 IRQ Cascade 10 Available
3 COM2/COM4 11 SCSI
4 COM1/COM3 12 Mouse
5 LPT2 / Audio 13 Math
Coprocessor
6 FDD 14 Primary IDE
7 LPT1 15 Secondary IDE

7. DMA Channels
• 0-3 8-bit
• 4 is cascade
• 5-7 is 16-bit

8. POST
• Power On Self Test
• The computer will beep if errors are
encountered here
• Beep code meanings are determined
based on the BIOS type
– Phoenix
– AMI
– Award

9. Loading the OS
• Seeks out devices in the order BIOS
specifies
• Locates the MBR (Master Boot
Record) on the device
• MBR specifies where the OS is
located on the device

10. Loading the OS
• Seeks out devices in the order BIOS
specifies
• Locates the MBR (Master Boot
Record) on the device
• MBR specifies where the OS is
located on the device