IRQ6 Diskette drive interface
IRQ7 Parallel port
IRQ8 RTC
IRQ9 Available if ACPI is set to Off in System Setup program
IRQ10 Available
IRQ11 Available
IRQ12 Mouse controller
IRQ13 Math coprocessor
IRQ14 Primary EIDE interface (if Enabled in System Setup program)
IRQ15 Secondary EIDE interface (if Enabled in System Setup program)
NOTE: For the full name of an abbreviation or acronym used in this table, see the " Glossary ".
Memory Allocations
A processor and programs operating under MS - DOS (real-mode operation) can address only 1 megabyte (MB) (1024 kilobytes
[KB]) of system memory. This area is divided into conventional memory (sometimes called base memory) and upper memory. All
system memory above this 1 MB is called extended memory and cannot be directly addressed by MS-DOS -based programs
without the aid of some special memory - managing software.
Table B-10 provides a map of the conventional memory area. When the processor or a program addresses a location within the
conventional memory range, it is physically addressing a location in main memory, which is the only main memory it can address
under MS-DOS.
Table B-10. Conventional Memory Map
Address Range Use
00000h-003FFh Interrupt vector table
00400h-004FFh BIOS data area
00500h-005FFh MS-DOS and BASIC work area
00600h-0FFFFh User memory
10000h-1FFFFh User memory
20000h-2FFFFh User memory
30000h-3FFFFh User memory
40000h-4FFFFh User memory
50000h-5FFFFh User memory
60000h-6FFFFh User memory
70000h-7FFFFh User memory
80000h-8FFFFh User memory