Discrimination Between Cpu And Ram1 - Radio Shack TRS-80 Service Manual

E. Discrimination Between CPU and RAM 1
If a test unit passes the preceding checking procedures and a problem still exists,
follow the calculations.
(1) Manual Calculations Below
Perform the following calculations manually.
1
+
2)1:
(3
+
4)1: (5
+
6)1: (7
+
8)))
Correct answer 767.
(In DEG mode)
(TAN(COS(SIN(LOG 100) ))) IEXEI
Correct answer 0.0174550616
After execution of this program,
display should show END.
10 FOR I
=
1 TO 2 : FOR J
=
1 TO 2 : FOR
FOR L
=
1 TO 2
20 NEXT L : NEXT K : NEXT J : NEXT
30 GOSUB 40 PRINT "END" : END
40 GOSUB 50 RETURN
50 GOSUB 60 RETURN
60 GOSUB 70 RETURN
70 GOSUB 80 RETURN
80 GOSUB 90 RETURN
90 GOSUB 100 RETURN
100 GOSUB 110 RETURN
110 RETURN
If the above calculations cannot be made, the CPU may be faulty.
(2)
Program
Execute the following program after pushing the ALL RESET button on the bottom.
K
=
1 TO 2:
If the above manual calculations (1) are done but the program (2) cannot be executed,
RAM 1 may be faulty.
-10-