User Guide

3.6 Memory Test 3 chTests and Diagnostics
3.6 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 256-byte unit of constant data to conventional
memory (0 to 640 KB). Then reads the new data and compares the result
with the original data. The content of the memory to be tested is saved
before the test and it is restored after the test.
The constant data is FFFFh, AAAAh, 5555h, 0101h and 0000h.
Subtest 02 Protected Mode
NOTE: The CONFIG.SYS file must be configured without extended 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 (FFh, AAh, 55h, 00h) and address data
(FFFFh, FFFEh, … 0000h) to from 1MB to the maximum MB then reads
the new data and compares the result with the original data and executes
the address bit test (in 64KB unit. FFh, FEh, …).
Subtest 04 Cache Memory
To test the cache memory, a pass-through write-read comparison of ‘5A’
data is run repeatedly to the test area (‘7000’:’Program’ size to
‘7000’:’7FFF’ (32KB)) to check the hit-miss ratio (on/off status) for CPU
cache memory.
Number of misses < Number of hits → OK
Number of misses ≥ Number of hits → Fail
Satellite A50/TECRA A2 Maintenance Manual (960-478) 3-15