Table of Contents
Advertisement
Most
BASICS,
however,arenotquitethatstraightfonvard. F orexample,the
IBM-PC
will give
you
a printoutsimilarto Figure2-5.
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
! " 4+$%!%'( )
x+, -. /
O 123456789:
: .::= ::. ?
@ABCDEFGHIJF::LMNO
PQF:STLIVWXYZ [ \ 1'"'-
' abcde+g
h i j l:.1mno
pqh. 5tLlVW>:y Z
: : ]+.
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
".
Figure2-5. Sample hexadecimal dump with IBM-PC
When the IBM-PCBASICinterpretersendshex codeOD(carriagereturn)
it adds an extra hex OA(line feed). Hex code 1A (end-of-fde)also gets
special treatment:the interpreterdoes not send it at all. This can cause
problemswithgraphicsordownloadcharacterdata.However,youcansolve
this problemby changingline 20 in the precedingprogramand addingthe
codingshownbelow.
Codingfor IBM-PCwith monochromedisplay:
20 GOSUB 100
100 O==INP(&H3BD) : IF 0<128
THEN 100
110 OUT &H3BC, I
: OUT &H3BE,5
: OUT &H3BE, 4
1204 RETURN
Codingfor IBM-PCwith color adapter:
20 GOSUB 100
100 O=INP (&H379 ) : IF 0<128
THEN 100
110 OUT &H378, I
: OUT &H37A, 5
: OUT &H37A, 4
120 RETURN
ill
Advertisement
Table of Contents
