Dell Inspiron 3700 - Manual (Page 51)

Memory Allocations
Table 4 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
Table 5 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
Table 6 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