writing a hex value to file

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paulus123
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Posts: 1
Joined: Fri Oct 25, 2013 11:14 am

writing a hex value to file

Post by paulus123 »

Hi,
I have a hex value as string and want to write it to a file.
the hex number is F088 for example
this should be $F0 and $88 in the file and take two bytes of space.
(hi and low byte)
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burger2227
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Posts: 2466
Joined: Mon Aug 21, 2006 12:40 am
Location: Pittsburgh, PA

Re: writing a hex value to file

Post by burger2227 »

HEXadecimal values use 2 characters to express one byte of information.

That would require 4 bytes to express it as a HEX$ value, but you could convert each two characters into an ASCII byte value ranging from 0 to 255 for 00 to FF.

So if we have the HEX$ text values we can use VAL with "&H" prefix to get the byte value:

hexa$ = "F0"
byte% = VAL("&H" + hexa$)

We can then PRINT # or PUT # the value into a file as an ASCII character:

ascii$ = CHR$(byte%) '0 to 255 only
PUT #1, , ascii$

If you use QB64 you can put each value into a file AS _UNSIGNED _BYTE.
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