Q50004: Example of Saving Numeric Array to Disk Using BLOAD and BSAVE

Article: Q50004
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# S891017-63 B_BasicCom | mspl13_basic
Last Modified: 12-DEC-1989

The program below demonstrates how to BSAVE a numeric array as a
memory image file to disk and how to BLOAD the array from disk into a
new array in memory.

This information applies to Microsoft QuickBASIC Versions 4.00, 4.00b,
and 4.50, to Microsoft BASIC Compiler Versions 6.00 and 6.00b for
MS-DOS, and to Microsoft PDS Version 7.00 for MS-DOS.

The BSAVE statement allows you to copy the contents of a memory
location to a memory-image file on disk. A memory-image file is a
byte-for-byte copy of what is in memory along with control information
used by BLOAD to load the file. The program below initializes an
array, transfers the contents of it to an output file using BSAVE,
erases that array from memory, and then loads the saved array into a
new array in memory using BLOAD.

Code Example
------------

REM $DYNAMIC
DIM array%(8, 8)       ' 9 elements per dimension.
FOR i% = 0 TO 8        ' Initialize the array with desired values.
    FOR j% = 0 TO 8
        array%(i%, j%) = i% + j%   ' Arbitrary values assigned.
    NEXT j%
NEXT i%
' Set DEF SEG at the segment (paragraph address) of the array:
DEF SEG = VARSEG(array%(0, 0))
' Specify the output disk file name (JUNK.DAT), the offset of the
' starting address of the area in memory to be saved, and the number
' of bytes to save (9*9*2 is 162 bytes):
BSAVE "Junk.dat", VARPTR(array%(0, 0)), 162
DEF SEG                'Restore BASIC segment to default
PRINT "After save"
ERASE array%
DIM array2%(8, 8)      ' Dimension new array.
DEF SEG = VARSEG(array2%(0, 0))   ' Set DEF SEG for subsequent BLOAD.
BLOAD "Junk.dat", VARPTR(array2%(0, 0))   ' Reloads the array.
FOR j% = 0 TO 8
    FOR i% = 0 TO 8
        PRINT array2%(i%, j%);   ' Confirms array is reloaded.
    NEXT i%
    PRINT
NEXT j%

The following is the output for this program:

After save
 0  1  2  3  4  5  6  7  8
 1  2  3  4  5  6  7  8  9
 2  3  4  5  6  7  8  9  10
 3  4  5  6  7  8  9  10  11
 4  5  6  7  8  9  10  11  12
 5  6  7  8  9  10  11  12  13
 6  7  8  9  10  11  12  13  14
 7  8  9  10  11  12  13  14  15
 8  9  10  11  12  13  14  15  16

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