System Memory; Memory Map - NEC VERSA 2600 Service Manual

1-14 Technical Information

SYSTEM MEMORY

The system board provides 16-MB of standard random access memory (RAM).
Optional memory DIMMS with a value of 8-, 16-, or 32-MB can be added to increase sys-
tem memory up to a maximum of 80-MB (70ns Fast Page access or HyperPage access).
The DIMMS must be added in pairs of the same capacity. In addition, 256-KB of read-only
memory (ROM), 1 x 28F020, enables the system BIOS to be flashed.
The system provides 1-MB (TFT models) or 1.5-MB (DSTN model) of video RAM (60ns
HyperPage mode, self refresh).
The following Cache RAM is provided:
T
L1:
16KB (Internal Pentium P54C-133)
32KB (Internal Pentium P55C-150MMX)
T
L2: 256 KB PipeLineBurst-SRAM.

Memory Map

The system supports system and video shadowing, both controlled through complementary
metal oxide semiconductor (CMOS). The system supports BIOS as a cacheable area with
write protection. Table Section 1-2 lists the system memory map.
Memory Space
0000000h-0009FFFFh
00A0000h-000B7FFF
00B8000h-000BFFFFh
00C0000h-000C9FFF
00CA000h-000CFFFFh
00D0000h-000DFFFFh
00E0000h-000FFFFFh
0000000h -00FFFFFFh
0000000h -FFFEFFFFh
Table Section 1-2 Memory Map
Size Function
640 KB DOS Applications & Optional Memory Space Gap
96 KB Video (VGA) Graphic Memory
32 KB Text Mode Memory (SMM Space)
40 KB Video (VGA) BIOS
24 KB PnP BIOS / PCI BIOS
64 KB Setup / PCMCIA Window (Extended Memory or
Upper Memory Block)
128 KB System BIOS ROM
16 MB Total Base Memory
80 MB Total Extension Memory