Texas Instruments TI-99/4A - Page 183

Character Definition
These subroutines print a given string beginning at a specified row
and column on the screen. Lines 770 through 810 print a string
horizontally. Lines 820 through 860 print a string vertically.
This subroutine is used to allow you to change the dots you have
turned on or off First. the new cursor location is checked. If the
cursor is at the end of the line and the RIG HT arrow key is
pressed. the cursor moves to the left side of the next line down. If
the cursor IS at the begmnmg of the hne and the LEFT arrow key
is pressed. the cursor moves to the right side of the next line up. If
the cursor is at the upper left corner and the LEFT arrow key is
pressed. the cursor moves to the lower right corner. If the cursor is
at the lower right corner and the RIGHT arrow key is pressed, the
cursor moves to the upper left hand corner.
A so.mple of the screen for u progro.m run is shown o.t the right.
User's Reference Guide
Examples:
;"600 Y-16
>610 x"12
>620 GOSUB 770
>630
M$="PR E S5 Q TO QUIT"
>"40 Y-18
>650 X=12
>660
GOSUB 770
>670 M$="PRES5
ANY OTHER"
>680 Y=19
>690 GOSUB 770
>700 M$="KEY TO CONTINUE"
>710 Y=20
>720 cOSUS 770
>730 CALL KEYCO,KEY,STATUS)
>740
IF STATUS=O THEN 730
>750 IF KEY<>81 THEN 140
>760 STOP
>770 fOR 1=1 TO LEN(M$)
>780 COOE=ASC(SEG$CM$,I,1»
>790
CALL HCHAR(Y,X+I,CODE)
>800 NEXT I
>810 RETURN
>820 fOR 1=1 TO LEN(M$)
>830 CODE=ASC(SEG$CM$,I,1»
>840 CALL HCHAR(Y+I,~,(ODE)
>850 f'lEXT I
>860 RETURN
>870 CALL HCHAR{8+R,4+C,100+B
(R, C) )
>880 IF KEY=9 THEN 960
>890 C=C-1
>900 IF
C<>O THEN 1020
>910 (=08
>920 R=R-1
>930 IF
R<>O THEN 1020
>940 R"'8
>950 GO TO 1 020
>960 C=C+1
>970 IF C<>9 THEN 1020
>980 C=1
>990 R:R+1
>1000 IF R<>9 THEN 1020
>1010 R=1
>1020 RETURN
>RUN
AUTO CHARACTER DEFINITION
flJ'"" f8 ~
~ FOFOFOFOFOFOFOFO
PRESS Q TO QUIT
u-OFF=WHIT£ PR£SS ANY OTHER
1=ON=BLACK KEY TO CONT1NUE
I1I-27