NEC PC-8201 Service Manual page 64

5.3.4 RS-232C Interface Operation Test
(Preparation
)
Connect the pin in Figure 5.21
with the RS-232C connector.
(
1
)
RS-232C Connector Test Program
Test using the program in Figure 5.20.
Repeat transmitting and receiving the data (address &H 1 to &HFF). and display
the received data on the monitor. then compare it with the transmitted
data.
If
the RS-232C interface is normal. you can confir111 each terminal
signal in Figure 5.22, "RS-232C TEST OK" is displayed when the test is
finished.
IT
it is abnormal, "RS-232C ERROR" is displayed.
10 OUT 144,192:OUT 216,27
20 OUT 188,3: OUT 189,64 :PRINT CHRB( 12)
30 FOR A = l TO 255:OUT 200,A:B=INP(200)
40 I F A<>B GOT0 80 ELSE PRINT B;
50 FOR N=l TO 100 :NEXT
60 NEXT
70 PRINT: PRINT
"
RS-232C TEST OK" :END
80 PR1NT:PRINT "RS-232C ERROR ! !":END
Figure 5.20 Test Program
RS.232C 25-pin D SUB CONNECTOR
Figure 5.21 Pin Connection
5-15
-
Pin number
1
S~gnal name
GND
2 T x D
I -
3
4
5
6
7
RxD
RTS
CTS
DSR
GND
1
DCD
1 0
I
20
22
25
D T
R
RD
. . .