	VRTARY: Virtual Array Access Routines for RT-11 and TSX-Plus

				Abstract

VRTARY contains routines for declaring, accessing, and eliminating a
two dimension array in extended memory.  The routines are written in
MACRO-11 and follow the FORTRAN subroutine calling protocol.  The size
of the array is limited only by the amount of memory that is available.
The number of elements in the array is limited by the size of the array
and the size of each element.  Access to the array is through a local
buffer in the calling program that must be capable of holding a single
row or column of array elements.  Calling sequences are documented in
the source file.

The first applications permitted the processing of some rather large
image arrays under RT-11 and TSX-Plus.  One image contained 640 by 480
1-byte pixels or elements.  This is 300K (K=1024) elements occupying
300Kb of memory.  The other image contained 512 by 512 or 256K 8-byte
pixels occupying 2048Kb or 2Mb of memory.

An additional application performed a two-dimension convolution on a
640 by 480 array of byte elenents.  It uses either a 3 by 3, a 5 by 5,
or a 7 by 7 mask.  This array also occupies 300Kb of memory.

Three sample FORTRAN programs are included in the package, one test
program and two application programs.  Documentation for these programs
is included in the source and indirect command files.

TSX-Plus prior to V5.1c limits the virtual array to less than 2Mb.

				N. A. Bourgeois, Jr.
				05-Jun-85
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