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MS-5128 version 1.0
CPU Clock Selection: SW1
The speed of the Intel Pentium CPU is decided by the ratio of the
CPU internal Clock and CPU external clock. SW1 bit 1, 2, and 3,
of the TR4 motherboard are used to choose the internal CPU Clock
ratio and bit 4, 5, and 6 are for the external CPU Clock speed.
The follwoing table is the setting for Intel and AMD:
|
CPU Internal
|
SW1( 1, 2, 3)
|
Ratio
|
SW1 ( 4, 5, 6)
|
Clock
|
|
1
|
2
|
3
|
4
|
5
|
6
|
1
|
2
|
3
|
4
|
5
|
6
|
|
75Mhz
|
OFF
|
OFF
|
OFF
|
|
|
|
1.5
|
|
|
|
OFF
|
ON
|
OFF
|
50MHz
|
|
90Mhz
|
OFF
|
OFF
|
OFF
|
|
|
|
1.5
|
|
|
|
OFF
|
OFF
|
ON
|
60MHz
|
|
100Mhz
|
OFF
|
OFF
|
OFF
|
|
|
|
1.5
|
|
|
|
OFF
|
OFF
|
OFF
|
66MHz
|
|
120Mhz
|
OFF
|
ON
|
OFF
|
|
|
|
2
|
|
|
|
OFF
|
OFF
|
ON
|
60MHz
|
|
133Mhz
|
OFF
|
ON
|
OFF
|
|
|
|
2
|
|
|
|
OFF
|
OFF
|
OFF
|
66MHz
|
|
150Mhz
|
OFF
|
ON
|
ON
|
|
|
|
2.5
|
|
|
|
OFF
|
OFF
|
ON
|
60MHz
|
|
166Mhz
|
OFF
|
ON
|
ON
|
|
|
|
2.5
|
|
|
|
OFF
|
OFF
|
OFF
|
66MHz
|
|
180Mhz (Reserved)
|
OFF
|
OFF
|
ON
|
|
|
|
3
|
|
|
|
OFF
|
OFF
|
ON
|
60MHz
|
|
200Mhz (Reserved)
|
OFF
|
OFF
|
ON
|
|
|
|
3
|
|
|
|
OFF
|
OFF
|
OFF
|
66MHz
|
Cyrix CPU Speed setting is different from either Intel or AMD:
|
CPU Internal
|
SW1( 1, 2, 3)
|
Ratio
|
SW1 ( 4, 5, 6)
|
Clock
|
|
1
|
2
|
3
|
4
|
5
|
6
|
1
|
2
|
3
|
4
|
5
|
6
|
| P 120 + |
OFF
|
ON
|
OFF
|
|
|
|
2
|
|
|
|
OFF
|
ON
|
OFF
|
50MHz
|
| P 133 + |
OFF
|
ON
|
OFF
|
|
|
|
2
|
|
|
|
ON
|
ON
|
ON
|
55MHz
|
| P 150 + |
OFF
|
ON
|
OFF
|
|
|
|
2
|
|
|
|
OFF
|
OFF
|
ON
|
60MHz
|
| P 166 + |
OFF
|
ON
|
OFF
|
|
|
|
2
|
|
|
|
OFF
|
OFF
|
OFF
|
66MHz
|
2. CPU Voltage Selector: JV1, JV2, JV3
There are four different types of voltage settings for the Intel
Pentium CPU: 2.8V, STD, VR and VRE. JV1~JV3 jumpers are used to
set the correct voltage for the CPU on the TR4 motherboard.
|
CPU Voltage
|
JV1
|
JV2
|
JV3
|
|
1
|
2
|
3
|
4
|
5
|
|
STD, VR (3.3~3.45V)
|
Short all
|
Open
|
Open
|
Short
|
Short
|
Open
|
Open
|
|
VRE (3.45~3.6V)
|
Short all
|
Open
|
Open
|
Short
|
Short
|
Open
|
Short
|
|
P55 (2.8~2.9V)
|
Open all
|
Short
|
Short
|
Open
|
Short
|
Short
|
Open
|
|