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Service Hints & Tips |
Document ID: SSCT-3JMDY7 |
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IBM PC - Processor upgrade jumpers
Applicable to: World-Wide
Service Information:
The "Installing Options" manual describes processor upgrades for PC 300 systems but does not cover a couple of situations that may arise.
Intel has recently released 100MHz i486 DX4 and 25/63MHz Pentium Overdrive upgrades. These have onboard 5v to 3.3v regulators so may be installed in any SX, DX or DX2 model of the PC-300. If a DX4 Overdrive is fitted, remove jumpers JP10 1-2 and 3-4 .This ensures that the DX4 runs at 3x the planar speed.
The base planar speed is set by jumper J37 (ON=25MHz OFF=33 MHz). Some examples:
1. When upgrading from an SX/33 to a DX2/50 or Pentium Overdrive 25/63, J37 must be ON.
2. When upgrading from a DX2/50 to a DX2/66, DX4/100 or Pentium Overdrive 33/83, J37 must be OFF
Note: If a DX4 Overdrive is installed, the Setup utility may report the processor type as "unknown" and the speed as 0MHz. However QCONFIG (from DOS) will measure the actual processor speed.
Search Keywords |
Intel | |
Hint Category |
Processors | |
Date Created |
06-09-95 | |
Last Updated |
22-01-99 | |
Revision Date |
13-04-99 | |
Brand |
IBM PC | |
Product Family |
PC 330, PC 350 | |
Machine Type |
6571, 6573, 6575, 6581, 6583, 6585 | |
Model |
Various | |
TypeModel |
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Retain Tip (if applicable) |
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