Technical Reference Guide
Compaq Deskpro Personal Computers
Third Edition - April 2001
3-7
Figure 3-4 shows the system memory map.
NOTE: All locations in memory are cacheable. Base memory is always mapped to DRAM. The next 128 KB 
fixed memory area can, through the north bridge,  be mapped to DRAM or to PCI space. Graphics RAM area is 
mapped to PCI or AGP locations.  
Figure 3–4. System Memory Map
High BIOS Area 
2 MB
Host/PCI Memory 
Expansion 
(496 MB) 
FFFF FFFFh
1 MB 
Graphics/SMRAM 
RAM (128 KB) 
System BIOS Area
(64 KB) 
Fixed Mem. Area 
(128 KB) 
Base Memory 
(512 KB) 
Extended BIOS 
Area 
Extended Memory
1
 MB
 
FFE0 0000h 
0100 0000h 
00FF FFFFh 
0010 0000h 
000F 0000h 
000E FFFFh 
000F FFFFh 
0000 0000h 
0007 FFFFh 
0008 0000h 
0009 FFFFh 
000B FFFFh 
000A 0000h 
512 KB 
640 KB 
16 MB 
4 GB 
Host, PCI, 
ISA Area 
DOS Compatibility 
 Area 
Option ROM  
(128 KB) 
000E 0000h 
000D FFFFh
000C 0000h 
512 MB 
Host,  
PCI, AGP Area 
PCI Memory 
(18 MB) 
FFDF FFFFh
FEC1 0000h 
FEC0 FFFFh 
APIC Config. Space 
(64 KB) 
FEBF FFFFh 
FEC0 0000h 
PCI Memory 
Expansion 
(3060 MB) 
1FFF FFFFh 
2000 0000h