Sharp PC7000A Service Manual page 7

3 MEMORY DIAGNOSTICS
11) Outline
The MEMORY DIAGNOSTICS program serves to test the
function of the memory (referred to as MEM in the follow*
ing explanation). The memory area which can be tested is
the entire accommodable area except for the vector area
-and the area where the MS-DOS is loaded.
(1.1) Test Menu display
When this program is started up, the system displays the
title and the memory test menu as shown in Figure
MEM-l.
This display is referred to as the MEM test menu.
SHARP Personal Computer System Diagnostics Level. 3
Data Dec/01/'85
MEMORY [1.11
Memory size =
~!!!!!! KB (OxOOOOO - Ox~!!!!!!!!!~)
(0) Marching
(1) Address complement
(2) Aging [Marching and ADCOMP]
Please input command?
~
Figure MEM·l MEM Test menu
The MEM test menu shows the memory capacity accom-
modated in the system on the upper screen.
Memory size =
!!!!!!~ KB (OxOOOOO - Ox~!!!~~!!!)
The maximum memory capacity of this personal computer
is 768 KB.
Prior to conducting the test, check whether the memory
capacity being displayed is the same as that being accom-
modated.
If the memory capacities are not identical, a part of the
memory chip has been damaged. At that time, the system
should be repaired.
(1.2) Selection of Test Menu
Enter the required test number on the test menu as follows:
[[0]] to [[2]] (1 digit)
+
[[.,I]] (When specifying [[0]],
it is possible to press [[ .,I]] only.)
The number being entered is displayed on the screen. When
pressing [[ .,I]] , the specified diagnostics program is start-
ed up_
To change the test number, delete the number being enter-
ed by using [[ . ] ] and then enter the correct number.
-5-
(1.3) EXiting Test Menu
PC-700DA
PC-7l0D
When [[ESC]] is entered before entering [[ .,I]], control
exits to the DIAG LOADER.
(1.4) Others
Parameters of each test program are entered through 10
key
+ [[ .,]],
When each test program is called, by
pressing [[ESC]], control exits to the MEM test menu
(Figure MEM-l).
(2) Description of Program
(2.1) Marching
(2.1.1) Outline
After writing fixed data to the entire memory area, the
system sequentially reads data and compares it.
After reading data, the system writes other data.
The test procedure is outlined as follows:
1) 0 -+ M:
'"~O'"
W
2) M -+ 0: '"~O'' R, "FF'" W
3) 0 -+ M: '"FF" R, ··EE" W
4)
M -+ 0: "EE" R, "DO'" W
5) 0 -+ M: '"DO" R, '"BB'" W
6) M -+ 0: "BB" R, "77" W
7) 0-+M:'"77"R,'"11"W
8)
M-+O: "11"R,"22"W
9) 0 -+ M: "22'" R, "44" W
10) M -+ 0: '"44'" R, ·'88" W
11) 0 -+ M: ··88'" R
where
test area 0 -+ M
data:::: "nn"
Memory read
=
R
Memory write
=
W
The program serVes to test the entire memory area display-
ed as the memory size in the order listed above.
(2.1.2) Operation
When specifying this test, enter the proper data to prompts
displayed sequentially as shown in Figure MEM-2.
(a) Test
(a.l) Specification of Error Stop
Error stop? [ 0: Yes, 1 : No]:!!!!
If an error oCCurs while conducting this test, specify
whether to abort or continue the test.
(a.2) Confirmation of Test Execution
Test start? [0: Yes, 1: No]
=
!!!
Confirm whether to execute the test or not.
When entering [[1]], the test can be conducted from
'"Specifications of Error Stop'" mentioned in (a.l). On the
other hand, when entering [[0]], the system displays the
screen as shown in Figure MEM-2 and starts the test.