Applied Engineering Viewmaster 80, Руководство пользователя, Страница: 28 / 37

HTAB
- This command was originally intended for use with a 40
column display only. Trying to HTAB beyond 40 columns will not
work. To position the cursor anywhere on the 80 column line, use the
POKE 36,n command ("n" is the column number between 0 and 79).
The program statements shown below demonstrate the use of the
HTAB command.
10 PRINT CHR$(12)
20 VTAB 10
30 POKE 36, 55: PRINT "APPLE II FOREVER! "
Cursor Positioning
Expansion-slot 80 column cards, including Viewmaster 80, do not
support text windowing (POKE 34,T and POKE 35,B), but you can
use the "Control-^ XY" cursor positioning command to emulate the
windowing feature. Please refer to Table C-2 and the following
BASIC program, which illustrates the use of this command.
10 PRINT CHR$(4);"PR#3"
20 INPUT "COLUMN COORDINATE: X = ";X:REM range 0 to 79
30 INPUT "LINE COORDINATE: Y = ";Y:REM range O to 23
40 PRINT CHR$(30); CHR$(X + 32); CHR$(Y + 32);
50 GOTO 20
The POS(0) command, used to return the cursor's current column
position, can be emulated by the PEEK 1403 command. PEEK 1531
will return the cursor's current line number.
Custom Cursor Shape
Upon initialization, the Viewmaster 80 cursor defaults to a solid,
slowly blinking rectangular shape. Both the cursor's blink rate and its
vertical size and position can be controlled from within a BASIC
program. This example program shows how the cursor shape and
blink rate can be altered.
10 PRINT CHR$(4);"PR#3"
20 VM = 49328
30 BLINK = 0
40 FIRST = 2
50 LAST = 5
60 POKE VM,10
70 POKE VM + 1,BLINK + FIRST
80 POKE VM, 11
90 POKE VM + 1, LAST
99 END
App. C - For Programmers Only... 19