Toshiba Portege M100 Maintenance Manual - Page 119

3 Tests and Diagnostics 3.5 Memory Test 3.5 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 press Enter. 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 04 Cache Memory 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 seconds. Number of misses < Number of hits → OK Number of misses ≥ Number of hits → Fail Subtest 05 L2 Cache Memory To test the L2 cache memory, a similar test to that for the cache memory is performed. Subtest 06 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. 3-12 PORTEGE M100 Maintenance Manual (960-452)