Technical information

CHAPTER 4
Expansion Features
72 RAM Expansion Slots
The computer accepts either one or two SO-DIMMs. The bottom slot can
accommodate a 1.5-inch SO-DIMM with up to 128 MB of SDRAM. The top slot
can accommodate a 2.0-inch SO-DIMM with up to 256 MB of SDRAM. The
memory controller configures the combined memory of the SO-DIMMs into a
contiguous array of memory addresses.
Note
The PowerBook G3 Series computer does not support
memory interleaving, so installing two SO-DIMMs of the
same size does not result in any performance gain. ◆
Address Multiplexing 4
Signals A[0] – A[13] on each RAM SO-DIMM make up a 14-bit multiplexed
address bus that can support several different types of SDRAM devices. Table
4-7 lists the types of devices that can be used in this computer by size,
configuration, and sizes of row and column addresses.
64 Mbits 512K x 32 x 4 2 16 MB 128 MB
128 Mbits 4M x 8 x 4 8 128 MB 256 MB
128 Mbits 2M x 16 x 4 4 64 MB 256 MB
Table 4-7 Types of DRAM devices
Device size
Device
configuration
Size of
row address
Size of
column
address
16 Mbits
2M x 4 x 2
11 10
16 Mbits
1M x 8 x 2
11 9
16 Mbits
512K x 16 x 2
11 8
64 Mbits
8M x 4 x 2
13 10
Table 4-6 Sizes of RAM expansion devices and modules (continued)
Device size
Device
configuration
Devices
per bank
Size of
each bank
Size of
SO-DIMM