Toshiba T3400, Maintenance Manual

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3-10 T3400, T3400CT
3.5 Memory Test
To execute the Memory Test, select 2 from the DIAGNOSTIC TESTS menu, press Enter
and follow the directions displayed on the screen. Move the highlight bar to a subtest 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 original
data.
Constant data is FFFFh, AAAAh, 5555h, 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
(program end to 640 KB), then reads the new data and compares the result
with 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 original data.
Constant data is AAAAh and 5555h.
NOTE: There is a short delay between write and read operations, depending on
data size.
Subtest 04 Protected mode
This subtest writes constant data and address data to extended memory (maxi-
mum address 100000h) then reads new data and compares the result with
original data.
Constant data is FFh, AAh, 55h, and 00h.