Memory Test - Toshiba T6400 Maintenance Manual

Table of Contents

3.5

Memory Test

To execute the Memory Test , type 2 from the DIAGNOSTIC TEST MENU, press Enter, and

follow the directions displayed on the screen. The Memory Test contains five subtests that test the

following T6400 memories: RAM constant data, RAM address pattern data, RAM refresh (real

mode), protected mode, and memory module. Select the number corresponding to the subtest you

want to execute and press Enter.

Subtest 01

RAM Constant Data

This subtest writes constant data FFFFh, AAAAh, 5555h, 0101h, and 0000h to

conventional memory (0 to 640KB). The constant data is then read from conven-

tional memory and compared to the original data.

Subtest 02

RAM Address Pattern Data

This subtest writes address pattern data created by eXclusive-ORing (XORing) to

the address segment and address offset in conventional memory (0 to 640KB). The

address pattern data is then read from conventional memory and compared to the

original data.

Subtest 03

RAM Refresh (Real Mode)

This subtest writes a 256-byte unit of constant data (AAAAh and 5555h) to conven-

tional memory (0 to 640KB). This data is then read from conventional memory and

compared to the original data.

NOTE: The size of the data being read and written to conventional memory causes a short

delay between write and read operations.

Subtest 04

Protected Mode

This subtest writes constant data FFh, AAh, 55h, 00h and address data to extended

memory (addressed 100000h to the maximum address). The data is then read from

extended memory and compared to the original data.

3-13

Table of Contents

Show Quick Links

Table of Contents