Memory allocations, I/o memory map – Dell Inspiron 3700 User Manual
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Memory Allocations
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.
Table 4. Conventional Memory Map
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).
When the microprocessor or a program addresses a location within the upper memory area, it is physically addressing a location within one of
these devices.
Table 5. Upper Memory Map
I/O Memory Map
provides a map of memory addresses reserved by the system for peripheral input/output (I/O) devices. Use the information in Table 6 to
IRQ2
Reserved; generated internally by the interrupt controller to enable IRQ8 through IRQ15
IRQ3
Available for use by a PC Card unless the integrated serial port or infrared port is configured for COM2 or COM4
IRQ4
Available for use by a PC Card unless the integrated serial port or infrared port is configured for COM1 (the default) or COM3
IRQ5
Available for use by the audio controller
IRQ6
Generated by the diskette drive controller to indicate that the diskette drive requires the attention of the microprocessor
IRQ7
Available for use by a PC Card or audio controller if the parallel port is disabled
IRQ8
Reserved; generated by the system I/O controller's real-time clock (RTC)
IRQ9
Reserved; generated by the video controller
IRQ10
Available for use by a PC Card or audio controller unless the Inspiron 3700 Advanced Port Replicator (APR) is attached
IRQ11
Generated by Universal Serial Bus (USB), PC Card, and audio controllers; available for use by a PC Card
IRQ12
Reserved; generated by the keyboard controller to indicate that the output buffer of the DualPoint™ integrated pointing device or the
external 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 drive in the media bay to indicate that the drive requires the attention of the microprocessor
NOTE: To view memory allocations in 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.
Address Range
Use
0000h-003FFh
Interrupt vector table
00400h-00FFFF
BIOS data area
00500h-005FFh
MS-DOS
® and BASIC work area
00600h-9FBFFh
User memory
Address Range
Use
0009FC00-0009FFFF
PS/2-mouse data area
000A0000-000BFFFF
Video random-access memory (RAM)
000C0000-000CFFFF
Video BIOS
000CC000-000CDFFF
Reserved for PC Card
000F0000-000FFFFF
System BIOS
00100000-03FFFFFF
High memory area
FD000000-FDFFFFFF
Video RAM
FF200000-FF2FFFFF
Video RAM
FFFE0000-FFFFFFFF
BIOS ROM