Tandy 1000 Programmer's Reference Guide

Chapter 6 I BIOS Services
Keyboard
16 hex (22 dec)
Function Summary:
AH = 0: Read Keyboard (destructive with wait)
AH = 1: Scan Keyboard (nondestructive, no wait)
AH = 2: Get Current Shift Status
Function Descriptions:
Read Keyboard
Read the next character typed at the keyboard. Return the AS-
CII value of the character and the keyboard scan code, removing
the entry from the keyboard buffer (destructive read).
Entry Conditions:
AH = 0
Exit Conditions:
AL = ASCII value of character
AH = keyboard scan code
Scan Keyboard
Set up the zero flag (Z flag) to indicate whether a character is
available
to be read from the keyboard or not. If a character is
available, return the ASCII value of the character and the key-
board scan code. The entry remains in the keyboard buffer (non-
destructive read).
Entry Conditions:
AH = 1
Exit Conditions:
Z = no character is available
NZ = a character is available, in which case:
AL = ASCII value of character
AH = keyboard scan code
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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