Epson MX-80 User Manual page 64

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Chapter 9

ght! The first 3 categories are present. Now, what coding scheme does each

-^category represent?

1. Greater than 100: Reserved for graphic characters. 32 added to the

number (for ASCII offset) and printed. Users in restricted TRS-80 mode

(SW# 2-4 ON), must remove the +32 in lines 20 & 30.

2. Between 0 and 100: Reserved for the "counter" in STRINGS. If " A "

reads a "counter", "B" then reads next DATA number which will be

>100, thus graphic. STRINGS prints B+32 a total of A times.

3. 0: Signals a CR and LF via a plain old LPRINT.

4. If none of above, defaults to line 50 which converts negative value to

positive, then ON-GOSUB to a print line (which we have yet to type in).

Even tho we haven't yet completed the program, isn't the logic flow nice and easy

to follow?

Micro-Analysis

Let's now go inside DATA line 90 and see what is being READ into the logic

system we examined above.

90 DATA

1 5 1 , 1 6 3 , 1 5 9 , 1 7 5 , 1 4 7 , 1 6 3 , 1 4 7 , 1 9 , 1 3 1 , 1 7 1 , 0

One Piece of Data At a Time

151 is a graphics character. 151 + 32 = 183. Check Appendix G to see

what it should look like.

Using the Editor, change(C) the comma following 1 5 1 in line 90 to a colon,

making it look like this

90 DATA 1 5 1 : 1 6 3 , 1 5 9 , 1 7 5

. . . .

e t c .

and RUN.

F i g u r e 7-5

Sure enuf, that's what we get.

Again using the Editor, move the colon to after the 163. Replace the comma

after 151.

What does ASCII 163 stand for? 163+32 = 195.

now RUN, READing 2 pieces of DATA