IRQ6 Generated by the diskette drive controller to indicate that the diskette drive requires the attention of the
microprocessor
IRQ7 Parallel port; available if parallel port is disabled
IRQ8 Reserved; generated by the real time clock
IRQ9 SCI in ACPI mode
IRQ10 PCI IRQA, B, C, D
IRQ11 Available
IRQ12 Reserved; generated by the keyboard controller to indicate that the output buffer of the touch pad or
PS/2 mouse is full
IRQ13 Reserved; generated by the math coprocessor
IRQ14 Reserved; generated by the hard-disk drive to indicate that the drive requires the attention of the
microprocessor
IRQ15 Reserved; generated by the CD-ROM or DVD-ROM drive in the external media bay to indicate that the
drive requires the attention of the microprocessor
Memory Allocations
Table 3 provides a map of the conventional memory area. When the microprocessor or a program addresses a location within the conventional memory
range, it is physically addressing a location in main memory.
NOTE: To view memory allocations in Windows 95 and Windows 98, click the Start button, point to Settings, and click Control Panel.
Double-click the System icon. Click the Device Manager tab, and then double-click Computer.
Table 3. Conventional Memory Map
Address Range Use
0000h-003FFh Interrupt vector table
00400h-004FFh BIOS data area
00500h-005FFh MS-DOSĀ® and BASIC work area
00600h-9FBFFh User memory
Table 4 provides a map of the upper memory area. Some of these addresses are dedicated to various system devices, such as the system/video basic
input/output system (BIOS). Others are available for use by expansion cards and/or an expanded memory manager (EMM).
Error Messages, IRQs, and Memory Assignments: Dell Latitude LS Portable Computers User's Guide
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