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3.7 Memory Test 3 Tests and Diagnostics
PORTEGE A200 Maintenance Manual (960-499) 3-17
3.7 Memory Test
To execute the Memory Test, select 2 from the DIAGNOSTIC TEST MENU, press Enter and
follow the directions on the screen. Move the highlight bar to the subtest you want to execute and
Subtest 01 Conventional memory
This subtest writes a constant data to conventional memory (0 to 640 KB), then
reads the new data and compares the result with the original data.
Subtest 02 Protected Mode
Note: The CONFIG.SYS file must be configured without expanded memory manager
programs such as EMM386.EXE, EMM386.SYS or QEMM386.SYS. Also, the
HIMEM.SYS must be deleted from the CONFIG.SYS file.
This subtest writes constant data and address data (from 1MB to maximum MB),
and reads the new data and compares the result with the original data.
Subtest 03 Protected Mode (Cache off)
This subtest executes the same way as the subtest 02 with the cache off.
Subtest 04 Cache Memory (on/off)
To test the cache memory, a pass-through write-read comparison of ‘5Ah’ data is
run repeatedly to the test area (‘7000’: ‘Program’ size to ‘7000’: ‘7FFF’ (32 KB))
to check the hit-miss ratio (on/off status) for CPU cache memory. One test takes 3
Number of misses ? Number of hits ? OK
Number of misses ? Number of hits ? Fail
Subtest 05 Stress
Data (from 1MB to the maximum MB) is written from the 16KB write buffer to the
16KB read buffer and compared the data in the buffers. The read buffer starts from
0001 and the comparison is continued with the following read buffer addresses:
0001, 0003, 0005, 0007, 0009, 000b, 000d and 000f.