When the IBM-PC BASIC interpreter sends hex code OD (carriage return)
it adds an extra hex OA (line feed). Hex code 1A (end-of-file) also gets
special treatment: the interpreter does not send it at ah. This can cause
problems that generate graphics or download character data, but there is a
solution. Try changing line 20 in the preceding program and adding the
coding shown below.
Coding for IBM-PC with monochrome display:
20 GOSUB 100
100 O=INP(&H379) :IF 0<128 THEN 100
110 OUT &H378,1 : OUT &H37A, 5 :OUT &H37A,4
120 RETURN
Coding for IBM-PC with color adapter:
20 GOSUB 100
100 O=INP(&H3BD) :IF 0<128 THEN 100
110 OUT &H3BC,I :OUT &H3BE,5 :OUT &H3BE,4
120 RETURN
L
b
c
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