Troubleshooting
WADE-8011/WADE-8012 User’s Manual
5-5
System Memory Address Map
Each On-board device in the system is assigned a set of memory addresses, which
also can be identical of the device. The following table lists the system memory
address used for your reference.
Memory Area
Size
Device Description
0000-003F 1K
Interrupt
Area
0040-004F
0.3K
BIOS Data Area
0050-006F 0.5K
System
Data
0070-0E2E 54K
DOS
0E2F-0F6B 5K
Program
Area
0F6C-9BFF 562K
【
Available
】
= Conventional memory ends at 624K =
9C00-9D3F
5K
Extended Bios Area
9D40-9FFF 11K
Unused
A000-AFFF 64K
VGA
Graphics
B000-B7FF 32K
Unused
B800-BFFF 32K
VGA
Text
C000-CD7F 54K
Video
ROM
CD80-EFFF 138K
Unused
F000-FFF 64K
System
ROM
HMA
64K
First 64k Extended
Interrupt Request Lines (IRQ)
Peripheral devices can use interrupt request lines to notify CPU for the service
required. The following table shows the IRQ used by the devices on board.
Interrupt Request Lines IRQ
IRQ#
Current Use
Default Use
IRQ 0
System ROM
System Timer
IRQ 1
System ROM
Keyboard Event
IRQ 2
【
Unassigned
】
Usable
IRQ
IRQ 3
System ROM
COM2
IRQ 4
System ROM
COM1
IRQ 5
【
Unassigned
】
Usable
IRQ
IRQ 6
System ROM
Diskette Event
IRQ 7
【
Unassigned
】
Usable
IRQ
IRQ 8
System ROM
Real-Time Clock
IRQ 9
【
Unassigned
】
Usable
IRQ
IRQ 10
【
Unassigned
】
Usable
IRQ
IRQ 11
Video ROM
Usable IRQ
IRQ 12
System ROM
IBM Mouse Event
