Digital Equipment DEC 3000 Series Service Information page 18

System Overview,
Memory
Subsystem
1–4
Continued
The memory subsystem includes the following:

Four memory motherboards (MMB) that mount on the system
module. To have an operational memory subsystem, all four
MMBs must be present.

The memory arrays are spread among the four MMBs. Each
bank of memory consists of eight memory modules, two on
each MMB.
The memory subsystem can support up to 256M bytes, with a
future expansion of up to 1 gigabyte of memory.
The DEC 3000 Model 500/500S AXP system contains a high-
performance memory subsystem that uses ECC logic. Memory
can be configured with up to 256M byte (using 1M
up to 1 gigabyte (using 4M
2
4 DRAMs).
Continued on next page
2
4 DRAMs) or