iii
Contents
Preface.............................................................................................................................
xv
Abbreviations .................................................................................................................. xvii
Section 1
Technical Information
System Unit .....................................................................................................................
1-1
System Board ...........................................................................................................
1-2
Chipset .............................................................................................................
1-6
PCI and Memory Controller (PCMC) ....................................................
1-6
Local Bus Accelerators ..........................................................................
1-6
PCI-EISA Bridge Component ................................................................
1-7
EISA System Component (ESC)............................................................
1-7
Bus Architecture ..............................................................................................
1-7
Host Bus .......................................................................................................
1-8
PCI Bus ........................................................................................................
1-9
EISA Bus......................................................................................................
1-9
XD Bus.........................................................................................................
1-9
System Memory Bus ....................................................................................
1-9
Processor..........................................................................................................
1-9
Secondary Cache.............................................................................................. 1-10
Flash ROM....................................................................................................... 1-10
On-Board Peripherals ...................................................................................... 1-12
SCSI Circuitry .............................................................................................. 1-12
IDE Controller.............................................................................................. 1-12
Video Circuitry............................................................................................. 1-12
EISA SRAM................................................................................................. 1-12
Real-Time Clock (RTC)............................................................................... 1-13
System I/O Controller ...................................................................................... 1-13
I/O Mapping..................................................................................................... 1-13
NEC Proprietary Ports ..................................................................................... 1-15
Keyboard Controller Ports ............................................................................... 1-20
System Memory ............................................................................................... 1-21
Interrupt Controller .......................................................................................... 1-22
Video Controller .............................................................................................. 1-23
Video Memory ................................................................................................. 1-23
EISA Bus ......................................................................................................... 1-23