Instruction Manual

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 4. Conventional Memory Map
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
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
Address Range Use
0009FC00-0009FFFF PS/2-mouse data area
000A0000-000BFFFF Video 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
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 determine if the memory address of an external peripheral (such as a PC Card) conflicts with a memory address
reserved by the system.
Check the documentation of the external I/O device to determine its memory address. If there is a conflict with a memory address
reserved by the system, change the address of the device.
NOTE: To view I/O addresses 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 6. I/O Memory Map
Address Device
0000-001F DMA controller #1
0020-003F Interrupt controller #1
0040-005F System timers