Replacing the SIMM
893-743-A
I-5
Replacing the SIMM
The DRAM SIMM is installed in a SIMM socket labeled U21 on the printed
circuit board that is just under the hub cover. You need to remove the SIMM
already installed on the board before installing a new SIMM.
Model 281xSA hubs use 72-pin SIMMs. SIMM capacity is a function of the
number and type of memory devices on the SIMM.
There are currently three SIMM capacities that can be installed on the Model
281xSA hub (see Table I-1).
Table I-1. DRAM SIMM capacities and types
SIMM capacity
and type
Memory device
type
SIMM
manufacturer
SIMM
part number
2 MB (2 sides)
512 Kb
×
32, 70 ns
Texas Instruments
Motorola
NEC
Micron
TM512CBK32-70
MCM32512SG70
MC-42512A32F-70
MT16D51232G-7
4 MB (1 side)
1 Mb
×
32, 70 ns
Texas Instruments
Motorola
NEC
Hitachi
Micron
TM124BBK32-70
MCM32130SHG70
MC421000A32F-70
HB56D132BR-7A
MT8D132G-7
8 MB (2 sides)
2 Mb
×
32, 70 ns
Motorola
NEC
Hitachi
Micron
MCM32230SHG70
MC-422000A32F-70
HB56D232BS-7A
MT16D232G-7