Epson MX-80 User Manual page 60

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Chapter 9

Vertical Tabs

Vertical TABS are similar to Horizontal ones. While we can get to any line on the

paper by using enough LPRINTs, VTABs can simplify programming.

Replace the current program with this NEW one:

1 0 L P R I N T C H R $ ( 2 7 ) " C "

C H R $ ( 3 3 ) ;

2 0 L P R I N T C H R $ ( 2 7 ) " B "

C H R $ ( 1 3 8 )

CHR$ ( 1 4 8)

CHR$ ( 1 2 8 ) ;

3 0 L P R I N T

" V E R T I C A L "

C H R $ ( 1 3 9 ) " TABS"

C H R $ ( 1 3 9 ) " W O R K "

4 0 L P R I N T C H R $ ( 1 4 0 ) ;

: GOTO 2 0

and RUN

Smooth as silk. The explanation of how the program works is almost as simple:

Line 10 sets for form length at 33 lines.

Line 20 Esc"B" opens the door to receive V TABs

Line 20 sets Vert TABs at 10 (10+1 28) and 20 (20+128)

Line 20 closes the TAB door with a null 0. (0+128).

Line 30 prints "VERTICAL", TABs down to the 10th line and prints, TABs

down to 20 and prints. CHRS( 139) is the TAB " k e y "

Line 40 sends the Form Feed and keeps the loop closed.

Note the semicolons at the end of the commands in lines 10,20 and 40. Without

them we would slip a line here and there. The Printer will count every LF, but

unless we are printing on a form requiring every line to be positioned just so, we

would miss one now and then.

Did you notice that use of Vertical TABs sends the paper upward in a nice

smooth flow? If we did the same, thing in BASIC with LPRINTs, the paper would

move jerkily as each Line Feed was executed.

Carefully and properly done, Vertical TABs combined with Form Feeds are very

powerful programming tools for business applications.

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