Cram1 - Radio Shack TRS-80 Service Manual

C. RAM 1
(1) Remove optional RAM module if equipped.
(2) Push the ALL RESET button on the bottom.
(3) Operate DEFM 62!EXEI.
(4) Write the following program.
10 FOR I
=
1 TO 87
20 A
(I)
=
I
30 PRINT A
(I)
40 NEXT I
50 PRINT "RAM OK"
60 END
(5) After writing the above program, confirm that the remaining program step is O.
(6) Execute the program and confirm the display counts up from 1 to 87 and shows RAM
OK by every depression of the
[t~]key.
If the above operations cannot be made, RAM 1 may be faulty.
D. RAM2 (Optional RAM module)
(1) Install the RAM module in a PC-4.
(2) Push the ALL RESET button on the bottom.
(3) Operate
I
MODE] 1 and confirm that the remaining program step is 1568.
If the display shows the remaining step as 544 .
(a) RAM 2 is not functioning.
(b) Wiring between CPU and RAM 2 has failed.
(4) Operate. DEFM 190 IEXEI and confirm the display ***VAR:216.
(5) Write the following program.
10 FOR I = 1 TO 215
20 A
(I)
=
I
30 PRINT A
(I)
40 NEXT I
50 PRINT "MODULE OK"
(6) Execute the program and confirm the display counts up from 1 to 215 and shows
MODULE OK by every depression of!EXElkey.
If the above program is not performed, the RAM2 (optional RAM module) may be at. fault.
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