Hardware Reference
In-Depth Information
Although you might think that badly wired outlets would be a rare problem, I have seen
a large number of installations in which the outlets were wired incorrectly. Most of the
time, the problem is in the ground wire. An improperly wired outlet can result in unstable
system operation, such as random parity checks and lockups. With an improper ground
circuit,currentscanbeginflowingontheelectrical groundcircuitsinthesystem.Because
the system uses the voltage on the ground circuits as a comparative signal to determine
whether bits are 0 or 1, a floating ground can cause data errors in the system.
Memory Module Testers
Forhigh-volumeserviceshopsorlargecorporateenvironmentsservicingmanysystems,a
dedicated memory tester can offer efficiency, performance, and accuracy far beyond run-
ning memory test software on a PC. These testers are table-top devices designed to eval-
uate all types of memory modules and even individual chips. The main drawback is that
these testers can be somewhat expensive, costing thousands of dollars, but the cost can be
justified for those who need to test a lot of memory quickly and accurately.
Without one of these testers, you are reduced to testing memory by running diagnostic
programs on the PC and testing the memory as it is installed. This can be problematic be-
causememorydiagnosticprogramscandoonlytwothingstothememory:writeandread.
AdedicatedmemorytestercandomanythingsamemorydiagnosticrunninginaPCcan't
do, such as
