Tandy 1000 Programmer's Reference Guide

Chapter 1 I System Calls
Dealloc
Free Allocated Memory
Function Call 49H
Returns to the system pool a piece of memory that was allocated
by the Allocate Memory function call
(48H).
Entry Conditions:
AH = 49H
ES = segment address of memory area to be freed
Exit Conditions:
Carry set:
AX = error code
Carry not set:
No error.
Error Returns:
AX = 9
Invalid block. The block passed in ES is not one allo-
cated via the Allocate Memory function call
(48H).
Arena trashed. The internal consistency of the memory
arena has been destroyed. This
is due to a user pro-
gram changing memory that does not belong to
it.
AX = 7
Example:
Dealloc eq" 49H
mov es, block
mov ah, Dealloc
int 21 H
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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