user29915: I am new to bitcoin. When I use this online 'Script Execution' site, to calculate the SHA256 hash of 1, I get 4bf5122f344554c53bde2ebb8cd2b7e3d1600ad631c385a5d7cce23c7785459a
but using any other online calculator you get a different result 6b86b273ff34fce19d6b804eff5a3f5747ada4eaa22f1d49c01e52ddb7875b4b
So probably OP_SHA256 is not what I think, or something happens to input after 1 is pushed into stack. 

user24925: Your conflict is caused because you are hashing different values in the two situations. 
>>> import hashlib
>>> hashlib.sha256("1").hexdigest()
'6b86b273ff34fce19d6b804eff5a3f5747ada4eaa22f1d49c01e52ddb7875b4b'

Your online tools are showing the hash of the string "1". 
>>> hashlib.sha256("\x01").hexdigest()
'4bf5122f344554c53bde2ebb8cd2b7e3d1600ad631c385a5d7cce23c7785459a'

Bitcoin script stack elements are bytes, for OP_1 this is 01.

29915: <p>I am new to bitcoin. When I use this online <a href="http://webbtc.com/script" rel="noreferrer">'Script Execution'</a> site, to calculate the SHA256 hash of 1, I get <strong>4bf5122f344554c53bde2ebb8cd2b7e3d1600ad631c385a5d7cce23c7785459a</strong>
but using any other online calculator you get a different result <strong>6b86b273ff34fce19d6b804eff5a3f5747ada4eaa22f1d49c01e52ddb7875b4b</strong>
So probably OP_SHA256 is not what I think, or something happens to input after 1 is pushed into stack. </p>
 24925: <p>Your conflict is caused because you are hashing different values in the two situations. </p>

<pre><code>&gt;&gt;&gt; import hashlib
&gt;&gt;&gt; hashlib.sha256("1").hexdigest()
'6b86b273ff34fce19d6b804eff5a3f5747ada4eaa22f1d49c01e52ddb7875b4b'
</code></pre>

<p>Your online tools are showing the hash of the string "1". </p>

<pre><code>&gt;&gt;&gt; hashlib.sha256("\x01").hexdigest()
'4bf5122f344554c53bde2ebb8cd2b7e3d1600ad631c385a5d7cce23c7785459a'
</code></pre>

<p>Bitcoin script stack elements are bytes, for <code>OP_1</code> this is <code>01</code>.</p>
