Little Board™/486e Technical Manual

Table 2–6. Little Board/486e Memory Map

Memory Address

Function

 

 

0100000h – 3FFFFFFh

Extended memory

 

 

00F0000h - 00FFFFFh

64K ROM BIOS

 

 

00D0000h - 00EFFFFh

Byte-wide socket S0, if enabled, otherwise, free

 

 

00CC000h – 00CFFFFh

Onboard BIOS Expansion Flash device for Ethernet

 

boot PROM code

 

 

00C0000h - 00CBFFFh

Video BIOS for onboard flat panel video controller

 

 

00A0000h - 00BFFFFh

Normally contains video RAM, as follows:

 

CGA Video: B8000-BFFFFh

 

Monochrome: B0000-B7FFFh

 

EGA and VGA video: A0000-AFFFFh

 

 

000000h - 09FFFFh

Onboard DRAM

 

 

Expanded Memory and Extended Memory

Extended memory is a contiguous linear block of memory above 1M byte. Some programs require that memory be available as expanded or EMS memory, which makes memory available as pages rather than as a contiguous block. The procedure for accessing expanded memory is defined in the EMS LIM 4.0 specification.

Expanded memory can be converted into EMS memory by using the EMS emulation utilities in DOS. Current versions of DOS provide EMS emulation utilities, such as EMM386, that conform to the LIM 4.0 specification. Refer to the DOS technical documentation for instructions for using the EMS emulation utility.

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Ampro Corporation 486E manual Expanded Memory and Extended Memory, Memory Address Function