Memory Module Numbers - HP 400 Series Servicing Manual

in any or all of these four addresses. Parity errors are displayed during the Test
Memory phase of the self-test and testing continues.
Figure 4-16 shows how the memory modules are numbered.
Figure 4-16. Memory Module Numbers
Refer to Table 4-14 and Table 4-15 to determine the memory module with the failing
address. Memory modules are grouped in pairs called Module Pairs representing two
memory modules.
In Table 4-14 and Table 4-15, blocks of memory are identified by module pairs. For
example, an 8 MB block at the top of memory has addresses FFFFFFFF down through
FF800000. In Model 400t/dl system units, Table 4-14 lists two address ranges;
FFFFFFFF down through FFC00000 and FFB00000 down through FF800000. The en-
tire address range of FFFFFFFF down through FF800000 is used for the 8 MB block
consisting of two 4 MB memory modules in the pair. These two address ranges do not
mean that one is used for module A and the other for module B. Addresses for each
module are determined by the least significant bit for each address range. For Model
400s system units, Table 4-15 lists only one address range of FFFFFFFF down through
FF800000 for the 8 MB block because the 4 MB modules are the smallest used in
Model 400s system units.
Fault Isolation 4-55