image test

ch00.asciidoc

@@ -51,16 +51,17 @@ Symbols: B⃦, Ƀ, ฿
 Currency Code: BTC (unofficial), XBT (possible ISO standard)
 
 [[table_bitcoinunits]]
+.Table of bitcoin units from bitcoin wiki (link:$$https://en.bitcoin.it/wiki/Units$$[])
 [options="header"]
 |=======
 | Unit Name | Notation | Value 
 | bitcoin	| BTC or B⃦ | 1 BTC 
 | millibitcoin | mBTC or mB⃦ | 0.001 BTC or 1/1000th  
 | microbitcoin | μBTC or μB⃦| 0.000001 BTC or 1/1m 
-| satoshi |	| 0.00000001 BTC or 1/100m 
+| satoshi | satoshi | 0.00000001 BTC or 1/100m 
 |=======
 
-Table of bitcoin units from bitcoin wiki (link:$$https://en.bitcoin.it/wiki/Units$$[])
+
 
 
 ==== A network and protocol
@@ -90,6 +91,10 @@ The ledger is a record of all bitcoin transactions and can be independently veri
 
 Bitcoin's core innovation is the _blockchain_, a distributed, timestamped ledger. The ledger consists of a cryptographically verified chain of _blocks_, each of which contains transactions, new coins and a signature (hash) of the previous block. Each full bitcoin node in the network will keep a complete local replica of the blockchain, and independently verify all transactions and balances from that replica. 
 
+[[blockchain_diagram]]
+.Blockchain: A chain of blocks
+image::images/blockchain.png["A chain of blocks"]
+
 ==== Mining for blocks
 
 Bitcoin's security is underpinned by computation. The blockchain is formed by solving a problem, called the _proof-of-work_ (PoW) that requires a predictable computational effort, one that takes approximately 10 minutes for the entire network of bitcoin nodes to solve. The process is called _mining_, since it has diminishing returns, just like mining for precious metals. It works a bit like a global lottery, where every bitcoin miner attempts to find a solution to a cryptographic equation. The first miner to find a solution, broadcasts it on the peer-to-peer bitcoin network for others to verify and include in the blockchain. For any transaction to be included in the global blockchain, it must be verified and included inside a new block. Each block includes the fingerprint of the previous block int he chain and any new transactions that have occured in the intervening 10 minutes. 

ch01.asciidoc

@@ -11,6 +11,9 @@
 
 The very first block mined, by Satoshi Nakamoto on Sat, 03 Jan 2009, is included in the source code of any "full node" client, as the basis for validating the entire blockchain.
 
+https://blockexplorer.com/b/0
+
+
 [[genesis_block_cpp]]
 .The Genesis Block, statically encoded in the source code of the reference client
 link:$$https://github.com/bitcoin/bitcoin/blob/master/src/chainparams.cpp#L120$$[bitcoin/src/chainparams.cpp:line 120]