Toshiba Libretto 50CT, User Manual

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3.5 Memory Test 3 Tests and Diagnostics
3-10 Libretto 50CT/70CT Maintenance Manual
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. The Memory Test contains six subtests that test the
computer’s memory. Move the highlight bar to the subtest you want to execute and press
Enter .
Subtest 01 RAM constant data (real mode)
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 constant data is FFFFh, AAAAh, 5555h, 0101h, and 0000h.
Subtest 02 RAM address pattern data (real mode)
This subtest writes address pattern data created by the exclusive-ORing
(XORing), to the address segment and address offset in conventional memory
(from program end to 640 KB), then reads the new data and compares the
result with the original data.
Subtest 03 RAM refresh (real mode)
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 constant data is AAAAh and 5555h.
NOTE: There is a short delay between write and read operations,
depending on the size of the data.
Subtest 04 Protected mode
This subtest writes constant data and address data to extended memory
(maximum address 100000h), then reads the new data and compares the result
with the original data.