Tandy 1000 Basic Reference Manual

Chapter 10 I BASIC Keywords
ASC Function
ASC(strZng)
Returns the ASCII code for the first character of string.
ASC returns the value as a decimal number. If string is null, an
"Illegal function call" error occurs.
Example
PRINT ASC("A"1
prints 65, the ASCII code for A.
Sample Program
You can use ASC to be sure a program is receiving proper input.
Suppose you want
to write a program that requires the user to
input hexadecimal digits (0-9, A-F). To be sure that only those
characters are input, and all other characters are excluded, you
can insert the following routine.
100 INPUT "ENTER A HEXADECIMAL VALUE";N$
110 A = ASCCN$) 'get ASCII code
120 IF A>47 AND A<58 OR A>64 AND A<71 THEN PRINT
"OK.": GOTO 100
130 PRINT "VALUE NOT OK." : GOTO 100
98

Tandy 1000 Specifications

General

Processor	Intel 8088
Processor Speed	4.77 MHz
RAM	128 KB (expandable to 640 KB)
Operating System	MS-DOS 2.11
Manufacturer	Tandy Corporation
Release Year	1984
Storage	Single or double 5.25" floppy disk drive (360 KB), optional hard drive
Sound	Tandy 3-voice sound
Ports	Parallel, Serial
Graphics	CGA (Color Graphics Adapter)
Graphics Modes	320x200, 640x200