Owner's Manual

Review the hex dump for missing codes or codes that have

been changed or added to. Typical things to look for include: an

<LF> (ASCII 0AH) added after the <CR> (ASCII 0DH) code,

<HT> (ASCII 09H) changed into a series of spaces (ASCII 20H),

or <FF> (ASCII 0CH) changed into a series of <LF> (ASCII

0AH) codes.

The program illustrated above could, of course, be written in

any language that you wish to investigate.

Beyond finding problem codes, the hex dump feature also pro-

vides a way to check which codes are actually being sent to the

printer by a program. Just turn on the hex dump feature and run

the program. Then interpret the codes that are printed out.

If you are investigating a program that uses the graphics op-

tions, be prepared for a lot of printing since each byte of graphics

data is printed in hex. This can be several pages of hex dump

numbers. You can usually stop the printer after a couple of print

lines of graphic data have been printed.

Figure 7-2 shows the hex dump printout of the first graphics

demonstration program in Chapter 6. If you study the codes you

can see the graphics option command and the graphics data,

followed by a <CR> <LF>

1B 2A

00 0E 00 03 07 1F 3F 7E

70 60

21 19 05 03

Figure

7-2.

Hex dump printout of Chapter 6 graphics program