user124301: Is there a specific reason why 1D00FFFF is the target bit for the genesis block and not 1CFFFFFF? Both bits are forcing 8 zeros in the front of the hash (hexadecimal).
Regards steff

user208: In the custom uint256 encoding used in Bitcoin, bit 0x00800000 denotes the sign, so 0x1CFFFFFF actually denotes the value -2200(223 - 1). Obviously the target value cannot go negative, so this aspect of the encoding is not useful in this context, but for whatever reason, that's what Bitcoin's creator chose.

124301: <p>Is there a specific reason why 1D00FFFF is the target bit for the genesis block and not 1CFFFFFF? Both bits are forcing 8 zeros in the front of the hash (hexadecimal).</p>
<p>Regards steff</p>
 208: <p>In the custom uint256 encoding used in Bitcoin, bit 0x00800000 denotes the sign, so 0x1CFFFFFF actually denotes the value <em>-2<sup>200</sup>(2<sup>23</sup> - 1)</em>. Obviously the target value cannot go negative, so this aspect of the encoding is not useful in this context, but for whatever reason, that's what Bitcoin's creator chose.</p>
