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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 |
| | |
