Toshiba Portege R500 Maintenance Manual - Page 128

3 Tests and Diagnostics 3.7 Memory Test 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 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 03 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 seconds. Number of misses < Number of hits → OK Number of misses ≥ Number of hits → Fail Subtest 04 Stress Write/Read buffer (1 size = 1B30h) is prepared in the conventional memory. The data is made in the Write Buffer, the data in Write Buffer is written in the area of address of 1MB or after. The data is red in the Read Buffer and data is compared in area up to the maximum size. Data: FFh, FFh, FFh, FFh, FFh, 00h, 00h, 00h, 00h, FFh, FFh, FFh, 00h, FFh, 00h, 00h, FFh, 00h, 00h, FFh, FFh, FFh, FFh, 00h, 00h, 00h, AAh 3-16 [CONFIDENTIAL] PORTEGE R500 Maintenance Manual (960-634)