Tandy 1000 Programmer's Reference Guide

Chapter 1 I System Calls
StdConOutput
Display Character Function Call 02H
Displays a character on the video screen. If a CONTROL-
C
is typed, Interrupt 23H is executed.
Entry Conditions:
AH
= 02H
DL
= character to display
Macro Definition:
display-chr macro
mov
mov
int
endm
character
d1,character
ah,02H
21
H
Example:
The following program converts lowercase characters to
up-
percase before displaying them.
func-02H: read-k bd ;see Function 08H
CmP a I , "a"
11 uppercase ;don't convert
CmP a1
, "2"
19 uppercase ;don't convert
5ub al,20H ;convert
to FlSClI code
;for uppercase
uppercase: display-char
a1 ;THIS FUNCTION
J mP func-02H ;get another character
34

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