diff --git a/data_files/mmgen.cfg b/data_files/mmgen.cfg
index 31e99560..5bcc757d 100644
--- a/data_files/mmgen.cfg
+++ b/data_files/mmgen.cfg
@@ -35,8 +35,8 @@
 # Uncomment to override 'rpcpassword' in bitcoin.conf
 # rpc_password mypassword
 
-# Uncomment to set the Bitcoin datadir
-# bitcoin_data_dir /path/to/datadir
+# Uncomment to set the coin daemon datadir
+# daemon_data_dir /path/to/datadir
 
 # Set the default hash preset:
 # hash_preset 3
diff --git a/mmgen/addr.py b/mmgen/addr.py
index ba57111f..fc3a76e4 100755
--- a/mmgen/addr.py
+++ b/mmgen/addr.py
@@ -36,29 +36,28 @@ class AddrGenerator(MMGenObject):
 		assert atype in d
 		return super(cls,cls).__new__(d[atype])
 
-class AddrGeneratorP2PKH(MMGenObject):
+class AddrGeneratorP2PKH(AddrGenerator):
 	desc = 'p2pkh'
 	def to_addr(self,pubhex):
+		from mmgen.protocol import hash160
 		assert type(pubhex) == PubKey
-		from mmgen.bitcoin import hexaddr2addr,hash160
-		return BTCAddr(hexaddr2addr(hash160(pubhex)))
+		return CoinAddr(g.proto.hexaddr2addr(hash160(pubhex)))
 
 	def to_segwit_redeem_script(self,pubhex):
-		raise NotImplemented
+		raise NotImplementedError
 
-class AddrGeneratorSegwit(MMGenObject):
+class AddrGeneratorSegwit(AddrGenerator):
 	desc = 'segwit'
 	def to_addr(self,pubhex):
 		assert pubhex.compressed
-		from mmgen.bitcoin import pubhex2segwitaddr
-		return BTCAddr(pubhex2segwitaddr(pubhex))
+		return CoinAddr(g.proto.pubhex2segwitaddr(pubhex))
 
 	def to_segwit_redeem_script(self,pubhex):
 		assert pubhex.compressed
-		from mmgen.bitcoin import pubhex2redeem_script
-		return HexStr(pubhex2redeem_script(pubhex))
+		return HexStr(g.proto.pubhex2redeem_script(pubhex))
 
 class KeyGenerator(MMGenObject):
+
 	def __new__(cls,generator=None,silent=False):
 		if cls.test_for_secp256k1(silent=silent) and generator != 1:
 			if not opt.key_generator or opt.key_generator == 2 or generator == 2:
@@ -76,12 +75,41 @@ class KeyGenerator(MMGenObject):
 		except:
 			return False
 
+import ecdsa
 class KeyGeneratorPython(KeyGenerator):
+	# From electrum:
+	# secp256k1, http://www.oid-info.com/get/1.3.132.0.10
+	_p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2FL
+	_r = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141L
+	_b = 0x0000000000000000000000000000000000000000000000000000000000000007L
+	_a = 0x0000000000000000000000000000000000000000000000000000000000000000L
+	_Gx = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798L
+	_Gy = 0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8L
+	_curve_secp256k1 = ecdsa.ellipticcurve.CurveFp(_p,_a,_b)
+	_generator_secp256k1 = ecdsa.ellipticcurve.Point(_curve_secp256k1,_Gx,_Gy,_r)
+	_oid_secp256k1 = (1,3,132,0,10)
+	_secp256k1 = ecdsa.curves.Curve('secp256k1',_curve_secp256k1,_generator_secp256k1,_oid_secp256k1)
+
+	# devdoc/guide_wallets.md:
+	# Uncompressed public keys start with 0x04; compressed public keys begin with
+	# 0x03 or 0x02 depending on whether they're greater or less than the midpoint
+	# of the curve.
+	def privnum2pubhex(self,numpriv,compressed=False):
+		pko = ecdsa.SigningKey.from_secret_exponent(numpriv,self._secp256k1)
+		# pubkey = 32-byte X coord + 32-byte Y coord (unsigned big-endian)
+		pubkey = hexlify(pko.get_verifying_key().to_string())
+		if compressed: # discard Y coord, replace with appropriate version byte
+			# even Y: <0, odd Y: >0 -- https://bitcointalk.org/index.php?topic=129652.0
+			p = ('03','02')[pubkey[-1] in '02468ace']
+			return p+pubkey[:64]
+		else:
+			return '04'+pubkey
+
 	desc = 'python-ecdsa'
 	def to_pubhex(self,privhex):
 		assert type(privhex) == PrivKey
-		from mmgen.bitcoin import privnum2pubhex
-		return PubKey(privnum2pubhex(int(privhex,16),compressed=privhex.compressed),compressed=privhex.compressed)
+		return PubKey(self.privnum2pubhex(
+			int(privhex,16),compressed=privhex.compressed),compressed=privhex.compressed)
 
 class KeyGeneratorSecp256k1(KeyGenerator):
 	desc = 'secp256k1'
@@ -91,7 +119,7 @@ class KeyGeneratorSecp256k1(KeyGenerator):
 		return PubKey(hexlify(priv2pub(unhexlify(privhex),int(privhex.compressed))),compressed=privhex.compressed)
 
 class AddrListEntry(MMGenListItem):
-	addr  = MMGenListItemAttr('addr','BTCAddr')
+	addr  = MMGenListItemAttr('addr','CoinAddr')
 	idx   = MMGenListItemAttr('idx','AddrIdx') # not present in flat addrlists
 	label = MMGenListItemAttr('label','TwComment',reassign_ok=True)
 	sec   = MMGenListItemAttr('sec',PrivKey,typeconv=False)
@@ -306,7 +334,7 @@ Removed %s duplicate WIF key%s from keylist (also in {pnm} key-address file
 	def addrpairs(self):
 		return [(e.idx,e.addr) for e in self.data]
 
-	def btcaddrs(self):
+	def coinaddrs(self):
 		return [e.addr for e in self.data]
 
 	def comments(self):
@@ -316,7 +344,7 @@ Removed %s duplicate WIF key%s from keylist (also in {pnm} key-address file
 		for e in self.data:
 			if idx == e.idx: return e
 
-	def btcaddr(self,idx):
+	def coinaddr(self,idx):
 		for e in self.data:
 			if idx == e.idx: return e.addr
 
@@ -329,8 +357,8 @@ Removed %s duplicate WIF key%s from keylist (also in {pnm} key-address file
 			if idx == e.idx:
 				e.label = comment
 
-	def make_reverse_dict(self,btcaddrs):
-		d,b = MMGenDict(),btcaddrs
+	def make_reverse_dict(self,coinaddrs):
+		d,b = MMGenDict(),coinaddrs
 		for e in self.data:
 			try:
 				d[b[b.index(e.addr)]] = MMGenID('{}:{}'.format(self.al_id,e.idx)),e.label
@@ -671,15 +699,15 @@ re-import your addresses.
 		if al_id in self.al_ids:
 			return self.al_ids[al_id]
 
-	def mmaddr2btcaddr(self,mmaddr):
+	def mmaddr2coinaddr(self,mmaddr):
 		al_id,idx = MMGenID(mmaddr).rsplit(':',1)
-		btcaddr = ''
+		coinaddr = ''
 		if al_id in self.al_ids:
-			btcaddr = self.addrlist(al_id).btcaddr(int(idx))
-		return btcaddr or None
+			coinaddr = self.addrlist(al_id).coinaddr(int(idx))
+		return coinaddr or None
 
-	def btcaddr2mmaddr(self,btcaddr):
-		d = self.make_reverse_dict([btcaddr])
+	def coinaddr2mmaddr(self,coinaddr):
+		d = self.make_reverse_dict([coinaddr])
 		return (d.values()[0][0]) if d else None
 
 	def add_tw_data(self):
@@ -710,8 +738,8 @@ re-import your addresses.
 		else:
 			raise TypeError, 'Error: object %s is not of type AddrList' % repr(addrlist)
 
-	def make_reverse_dict(self,btcaddrs):
+	def make_reverse_dict(self,coinaddrs):
 		d = MMGenDict()
 		for al_id in self.al_ids:
-			d.update(self.al_ids[al_id].make_reverse_dict(btcaddrs))
+			d.update(self.al_ids[al_id].make_reverse_dict(coinaddrs))
 		return d
diff --git a/mmgen/bitcoin.py b/mmgen/bitcoin.py
deleted file mode 100755
index 39fcdad2..00000000
--- a/mmgen/bitcoin.py
+++ /dev/null
@@ -1,150 +0,0 @@
-#!/usr/bin/env python
-#
-# MMGen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
-# Copyright (C)2013-2017 Philemon <mmgen-py@yandex.com>
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-"""
-bitcoin.py:  Bitcoin address/key conversion functions
-"""
-
-import ecdsa
-from binascii import hexlify, unhexlify
-from hashlib import sha256
-from hashlib import new as hashlib_new
-import sys
-
-# From electrum:
-# secp256k1, http://www.oid-info.com/get/1.3.132.0.10
-_p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2FL
-_r = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141L
-_b = 0x0000000000000000000000000000000000000000000000000000000000000007L
-_a = 0x0000000000000000000000000000000000000000000000000000000000000000L
-_Gx = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798L
-_Gy = 0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8L
-_curve_secp256k1 = ecdsa.ellipticcurve.CurveFp(_p,_a,_b)
-_generator_secp256k1 = ecdsa.ellipticcurve.Point(_curve_secp256k1,_Gx,_Gy,_r)
-_oid_secp256k1 = (1,3,132,0,10)
-_secp256k1 = ecdsa.curves.Curve('secp256k1',_curve_secp256k1,_generator_secp256k1,_oid_secp256k1)
-
-# From en.bitcoin.it:
-#  The Base58 encoding used is home made, and has some differences.
-#  Especially, leading zeroes are kept as single zeroes when conversion happens.
-# Test: 5JbQQTs3cnoYN9vDYaGY6nhQ1DggVsY4FJNBUfEfpSQqrEp3srk
-# The 'zero address':
-# 1111111111111111111114oLvT2 (pubkeyhash = '\0'*20)
-_b58a='123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
-
-def _numtob58(num):
-	ret = []
-	while num:
-		ret.append(_b58a[num % 58])
-		num /= 58
-	return ''.join(ret)[::-1]
-
-def _b58tonum(b58num):
-	b58num = b58num.strip()
-	for i in b58num:
-		if not i in _b58a: return False
-	return sum(_b58a.index(n) * (58**i) for i,n in enumerate(list(b58num[::-1])))
-
-def hash160(hexnum): # take hex, return hex - OP_HASH160
-	return hashlib_new('ripemd160',sha256(unhexlify(hexnum)).digest()).hexdigest()
-
-def hash256(hexnum): # take hex, return hex - OP_HASH256
-	return sha256(sha256(unhexlify(hexnum)).digest()).hexdigest()
-
-# devdoc/ref_transactions.md:
-btc_addr_ver_nums = {
-	'p2pkh': { 'mainnet': ('00','1'), 'testnet': ('6f','mn') },
-	'p2sh':  { 'mainnet': ('05','3'), 'testnet': ('c4','2') }
-}
-btc_addr_pfxs             = { 'mainnet': '13', 'testnet': 'mn2', 'regtest': 'mn2' }
-btc_uncompressed_wif_pfxs = { 'mainnet':'5','testnet':'9' }
-btc_privkey_pfxs          = { 'mainnet':'80','testnet':'ef' }
-
-from mmgen.globalvars import g
-
-def verify_addr(addr,verbose=False,return_dict=False,testnet=None):
-	testnet = testnet if testnet != None else g.testnet # allow override
-	for addr_fmt in ('p2pkh','p2sh'):
-		for net in ('mainnet','testnet'):
-			ver_num,ldigit = btc_addr_ver_nums[addr_fmt][net]
-			if addr[0] not in ldigit: continue
-			num = _b58tonum(addr)
-			if num == False: break
-			addr_hex = '{:050x}'.format(num)
-			if addr_hex[:2] != ver_num: continue
-			if hash256(addr_hex[:42])[:8] == addr_hex[42:]:
-				return {'hex':addr_hex[2:42],'format':addr_fmt,'net':net} if return_dict else True
-			else:
-				if verbose: Msg("Invalid checksum in address '{}'".format(addr))
-				break
-
-	if verbose: Msg("Invalid address '{}'".format(addr))
-	return False
-
-def hexaddr2addr(hexaddr,p2sh=False,testnet=None):
-	testnet = testnet if testnet != None else g.testnet # allow override
-	s = btc_addr_ver_nums[('p2pkh','p2sh')[p2sh]][('mainnet','testnet')[testnet]][0] + hexaddr
-	lzeroes = (len(s) - len(s.lstrip('0'))) / 2
-	return ('1' * lzeroes) + _numtob58(int(s+hash256(s)[:8],16))
-
-def wif2hex(wif,testnet=None):
-	testnet = testnet if testnet != None else g.testnet # allow override
-	num = _b58tonum(wif)
-	if num == False: return False
-	key = '{:x}'.format(num)
-	compressed = wif[0] != btc_uncompressed_wif_pfxs[('mainnet','testnet')[testnet]]
-	klen = (66,68)[bool(compressed)]
-	if compressed and key[66:68] != '01': return False
-	if (key[:2] == btc_privkey_pfxs[('mainnet','testnet')[testnet]] and key[klen:] == hash256(key[:klen])[:8]):
-		return {'hex':key[2:66],'compressed':compressed,'testnet':testnet}
-	else:
-		return False
-
-def hex2wif(hexpriv,compressed=False,testnet=None):
-	testnet = testnet if testnet != None else g.testnet # allow override
-	s = btc_privkey_pfxs[('mainnet','testnet')[testnet]] + hexpriv + ('','01')[bool(compressed)]
-	return _numtob58(int(s+hash256(s)[:8],16))
-
-# devdoc/guide_wallets.md:
-# Uncompressed public keys start with 0x04; compressed public keys begin with
-# 0x03 or 0x02 depending on whether they're greater or less than the midpoint
-# of the curve.
-def privnum2pubhex(numpriv,compressed=False):
-	pko = ecdsa.SigningKey.from_secret_exponent(numpriv,_secp256k1)
-	# pubkey = 32-byte X coord + 32-byte Y coord (unsigned big-endian)
-	pubkey = hexlify(pko.get_verifying_key().to_string())
-	if compressed: # discard Y coord, replace with appropriate version byte
-		# even Y: <0, odd Y: >0 -- https://bitcointalk.org/index.php?topic=129652.0
-		p = ('03','02')[pubkey[-1] in '02468ace']
-		return p+pubkey[:64]
-	else:
-		return '04'+pubkey
-
-def privnum2addr(numpriv,compressed=False,segwit=False): # used only by tool and testsuite
-	pubhex = privnum2pubhex(numpriv,compressed)
-	return pubhex2segwitaddr(pubhex) if segwit else hexaddr2addr(hash160(pubhex))
-
-# Segwit:
-def pubhex2redeem_script(pubhex):
-	# https://bitcoincore.org/en/segwit_wallet_dev/
-	# The P2SH redeemScript is always 22 bytes. It starts with a OP_0, followed
-	# by a canonical push of the keyhash (i.e. 0x0014{20-byte keyhash})
-	return '0014' + hash160(pubhex)
-
-def pubhex2segwitaddr(pubhex):
-	return hexaddr2addr(hash160(pubhex2redeem_script(pubhex)),p2sh=True)
diff --git a/mmgen/globalvars.py b/mmgen/globalvars.py
index 81135511..f3d8bc2a 100755
--- a/mmgen/globalvars.py
+++ b/mmgen/globalvars.py
@@ -38,7 +38,7 @@ class g(object):
 		sys.exit(ev)
 	# Variables - these might be altered at runtime:
 
-	version      = '0.9.3'
+	version      = '0.9.399'
 	release_date = 'October 2017'
 
 	proj_name = 'MMGen'
@@ -51,7 +51,6 @@ class g(object):
 
 	coin   = 'BTC'
 	coins  = 'BTC','BCH'
-	ports = { 'BTC': (8332,18332), 'BCH': (8442,18442) }
 
 	user_entropy   = ''
 	hash_preset    = '3'
@@ -67,7 +66,7 @@ class g(object):
 	http_timeout = 60
 	max_int      = 0xffffffff
 
-	# Constants - some of these might be overriden, but they don't change thereafter
+	# Constants - some of these might be overriden in opts.py, but they don't change thereafter
 
 	debug                = False
 	quiet                = False
@@ -84,7 +83,6 @@ class g(object):
 	rpc_port             = 0
 	rpc_user             = ''
 	rpc_password         = ''
-	testnet_name         = 'testnet3'
 
 	bob                  = False
 	alice                = False
@@ -107,13 +105,12 @@ class g(object):
 		die(2,'$HOME is not set!  Unable to determine home directory')
 
 	data_dir_root,data_dir,cfg_file = None,None,None
-	bitcoin_data_dir = os.path.join(os.getenv('APPDATA'),'Bitcoin') if platform == 'win' \
-						else os.path.join(home_dir,'.bitcoin')
+	daemon_data_dir = '' # set by user or protocol
 
 	# User opt sets global var:
 	common_opts = (
 		'color','no_license','rpc_host','rpc_port','testnet','rpc_user','rpc_password',
-		'bitcoin_data_dir','force_256_color','regtest','coin','bob','alice'
+		'daemon_data_dir','force_256_color','regtest','coin','bob','alice'
 	)
 	required_opts = (
 		'quiet','verbose','debug','outdir','echo_passphrase','passwd_file','stdout',
@@ -132,7 +129,7 @@ class g(object):
 	cfg_file_opts = (
 		'color','debug','hash_preset','http_timeout','no_license','rpc_host','rpc_port',
 		'quiet','tx_fee_adj','usr_randchars','testnet','rpc_user','rpc_password',
-		'bitcoin_data_dir','force_256_color','max_tx_fee','regtest'
+		'daemon_data_dir','force_256_color','max_tx_fee','regtest'
 	)
 	env_opts = (
 		'MMGEN_BOGUS_WALLET_DATA',
diff --git a/mmgen/main_txsend.py b/mmgen/main_txsend.py
index 2a4f2ecb..ef139331 100755
--- a/mmgen/main_txsend.py
+++ b/mmgen/main_txsend.py
@@ -54,7 +54,7 @@ if not tx.marked_signed(c):
 	die(1,'Transaction is not signed!')
 
 if opt.status:
-	if tx.btc_txid: qmsg('{} txid: {}'.format(g.coin,tx.btc_txid.hl()))
+	if tx.coin_txid: qmsg('{} txid: {}'.format(g.coin,tx.coin_txid.hl()))
 	tx.get_status(c,status=True)
 	sys.exit(0)
 
diff --git a/mmgen/obj.py b/mmgen/obj.py
index 4af957cf..8816d939 100755
--- a/mmgen/obj.py
+++ b/mmgen/obj.py
@@ -28,7 +28,7 @@ from string import hexdigits,ascii_letters,digits
 def is_mmgen_seed_id(s): return SeedID(sid=s,on_fail='silent')
 def is_mmgen_idx(s):     return AddrIdx(s,on_fail='silent')
 def is_mmgen_id(s):      return MMGenID(s,on_fail='silent')
-def is_btc_addr(s):      return BTCAddr(s,on_fail='silent')
+def is_coin_addr(s):     return CoinAddr(s,on_fail='silent')
 def is_addrlist_id(s):   return AddrListID(s,on_fail='silent')
 def is_tw_label(s):      return TwLabel(s,on_fail='silent')
 def is_wif(s):           return WifKey(s,on_fail='silent')
@@ -302,7 +302,7 @@ class BTCAmt(Decimal,Hilite,InitErrors):
 
 	@classmethod
 	def fmtc(cls):
-		raise NotImplemented
+		raise NotImplementedError
 
 	def fmt(self,fs='3.8',color=False,suf=''):
 		s = self.__str__(color=False)
@@ -347,7 +347,7 @@ class BTCAmt(Decimal,Hilite,InitErrors):
 	def __neg__(self,other,context=None):
 		return type(self)(Decimal.__neg__(self,other,context))
 
-class BTCAddr(str,Hilite,InitErrors,MMGenObject):
+class CoinAddr(str,Hilite,InitErrors,MMGenObject):
 	color = 'cyan'
 	width = 35 # max len of testnet p2sh addr
 	def __new__(cls,s,on_fail='die'):
@@ -356,12 +356,11 @@ class BTCAddr(str,Hilite,InitErrors,MMGenObject):
 		try:
 			assert set(s) <= set(ascii_letters+digits),'contains non-ascii characters'
 			me = str.__new__(cls,s)
-			from mmgen.bitcoin import verify_addr
-			va = verify_addr(s,return_dict=True)
+			from mmgen.globalvars import g
+			va = g.proto.verify_addr(s,return_dict=True)
 			assert va,'failed verification'
 			me.addr_fmt = va['format']
 			me.hex = va['hex']
-			me.testnet = va['net'] == 'testnet'
 			return me
 		except Exception as e:
 			m = "{!r}: value cannot be converted to Bitcoin address ({})"
@@ -380,12 +379,15 @@ class BTCAddr(str,Hilite,InitErrors,MMGenObject):
 	def is_for_current_chain(self):
 		from mmgen.globalvars import g
 		assert g.chain,'global chain variable unset'
-		from bitcoin import btc_addr_pfxs
-		return self[0] in btc_addr_pfxs[g.chain]
+		return self[0] in g.proto.get_chain_protocol(g.chain).addr_pfxs
 
 	def is_mainnet(self):
-		from bitcoin import btc_addr_pfxs
-		return self[0] in btc_addr_pfxs['mainnet']
+		from mmgen.globalvars import g
+		return self[0] in g.proto.get_chain_protocol('mainnet').addr_pfxs
+
+	def is_testnet(self):
+		from mmgen.globalvars import g
+		return self[0] in g.proto.get_chain_protocol('testnet').addr_pfxs
 
 	def is_in_tracking_wallet(self):
 		from mmgen.rpc import rpc_connection
@@ -420,6 +422,7 @@ class MMGenID(str,Hilite,InitErrors,MMGenObject):
 	trunc_ok = False
 	def __new__(cls,s,on_fail='die'):
 		cls.arg_chk(cls,on_fail)
+		from mmgen.globalvars import g
 		try:
 			ss = str(s).split(':')
 			assert len(ss) in (2,3),'not 2 or 3 colon-separated items'
@@ -428,6 +431,7 @@ class MMGenID(str,Hilite,InitErrors,MMGenObject):
 			me.sid = SeedID(sid=ss[0],on_fail='raise')
 			me.idx = AddrIdx(ss[-1],on_fail='raise')
 			me.mmtype = t
+			assert t in g.proto.mmtypes,'{}: invalid address type for {}'.format(t,g.proto.__name__)
 			me.al_id = str.__new__(AddrListID,me.sid+':'+me.mmtype) # checks already done
 			me.sort_key = '{}:{}:{:0{w}}'.format(me.sid,me.mmtype,me.idx,w=me.idx.max_digits)
 			return me
@@ -518,13 +522,13 @@ class BitcoinTxID(MMGenTxID):
 class WifKey(str,Hilite,InitErrors):
 	width = 53
 	color = 'blue'
-	def __new__(cls,s,on_fail='die',testnet=None): # fall back to g.testnet
+	def __new__(cls,s,on_fail='die'):
 		if type(s) == cls: return s
 		cls.arg_chk(cls,on_fail)
 		try:
 			assert set(s) <= set(ascii_letters+digits),'not an ascii string'
-			from mmgen.bitcoin import wif2hex
-			if wif2hex(s,testnet=testnet):
+			from mmgen.globalvars import g
+			if g.proto.wif2hex(s):
 				return str.__new__(cls,s)
 			raise ValueError,'failed verification'
 		except Exception as e:
@@ -552,7 +556,7 @@ class PrivKey(str,Hilite,InitErrors,MMGenObject):
 	wif        = MMGenImmutableAttr('wif',WifKey,typeconv=False)
 
 	# initialize with (priv_bin,compressed), WIF or self
-	def __new__(cls,s=None,compressed=None,wif=None,on_fail='die',testnet=None): # default to g.testnet
+	def __new__(cls,s=None,compressed=None,wif=None,on_fail='die'):
 
 		if type(s) == cls: return s
 		assert wif or (s and type(compressed) == bool),'Incorrect args for PrivKey()'
@@ -561,12 +565,11 @@ class PrivKey(str,Hilite,InitErrors,MMGenObject):
 		if wif:
 			try:
 				assert set(wif) <= set(ascii_letters+digits),'not an ascii string'
-				from mmgen.bitcoin import wif2hex
-				w2h = wif2hex(wif,testnet=testnet)
+				from mmgen.globalvars import g
+				w2h = g.proto.wif2hex(wif)
 				assert w2h,"wif2hex() failed for wif key {!r}".format(wif)
 				me = str.__new__(cls,w2h['hex'])
 				me.compressed = w2h['compressed']
-				me.testnet = w2h['testnet']
 				me.wif = str.__new__(WifKey,wif) # check has been done
 				return me
 			except Exception as e:
@@ -578,16 +581,15 @@ class PrivKey(str,Hilite,InitErrors,MMGenObject):
 			assert len(s) == cls.width / 2,'Key length must be {}'.format(cls.width/2)
 			me = str.__new__(cls,hexlify(s))
 			me.compressed = compressed
-			me.wif = me.towif(testnet=testnet)
-#			me.testnet = testnet # leave uninitialized for now
+			me.wif = me.towif()
 			return me
 		except Exception as e:
-			fs = "Key={}\nCompressed={}\nValue pair cannot be converted to PrivKey ({})"
-			return cls.init_fail(fs.format(repr(s),compressed,e[0]),on_fail)
+			fs = "Key={!r}\nCompressed={}\nValue pair cannot be converted to PrivKey ({!r})"
+			return cls.init_fail(fs.format(s,compressed,e),on_fail)
 
-	def towif(self,testnet=None):
-		from mmgen.bitcoin import hex2wif
-		return WifKey(hex2wif(self,compressed=self.compressed),on_fail='raise',testnet=testnet)
+	def towif(self):
+		from mmgen.globalvars import g
+		return WifKey(g.proto.hex2wif(self,compressed=self.compressed),on_fail='raise')
 
 class AddrListID(str,Hilite,InitErrors,MMGenObject):
 	width = 10
@@ -660,7 +662,7 @@ class MMGenAddrType(str,Hilite,InitErrors,MMGenObject):
 	width = 1
 	trunc_ok = False
 	color = 'blue'
-	mmtypes = { # since 'name' is used to cook the seed, it must never change!
+	mmtypes = { # 'name' is used to cook the seed, so it must never change!
 		'L': {  'name':'legacy',
 				'comp':False,
 				'gen':'p2pkh',
@@ -704,5 +706,9 @@ class MMGenAddrType(str,Hilite,InitErrors,MMGenObject):
 
 class MMGenPasswordType(MMGenAddrType):
 	mmtypes = {
-		'P': {'name':'password','comp':False,'gen':None,'fmt':None,'desc':'Password generated from MMGen seed'}
+		'P': {  'name':'password',
+				'comp':False,
+				'gen':None,
+				'fmt':None,
+				'desc':'Password generated from MMGen seed'}
 	}
diff --git a/mmgen/opts.py b/mmgen/opts.py
index 3c71f896..e0a5bb4e 100755
--- a/mmgen/opts.py
+++ b/mmgen/opts.py
@@ -213,8 +213,14 @@ def init(opts_f,add_opts=[],opt_filter=None):
 
 	if g.regtest: g.testnet = True # These are equivalent for now
 
-#	Global vars are now final, including g.testnet, so we can set g.data_dir
-	g.data_dir=os.path.normpath(os.path.join(g.data_dir_root,('',g.testnet_name)[g.testnet]))
+	# g.testnet is set, so we can set g.proto
+	from mmgen.protocol import get_coin_protocol
+	g.proto = get_coin_protocol(g.coin,g.testnet)
+
+	if not g.daemon_data_dir: g.daemon_data_dir = g.proto.daemon_data_dir
+
+#	g.proto is set, so we can set g.data_dir
+	g.data_dir = os.path.normpath(os.path.join(g.data_dir_root,g.proto.data_subdir))
 
 	# If user opt is set, convert its type based on value in mmgen.globalvars (g)
 	# If unset, set it to default value in mmgen.globalvars (g)
@@ -243,10 +249,11 @@ def init(opts_f,add_opts=[],opt_filter=None):
 		mmgen.share.Opts.parse_opts(sys.argv,opts_data,opt_filter=opt_filter)
 
 	if g.bob or g.alice:
+		g.testnet = True
+		g.proto = get_coin_protocol(g.coin,g.testnet)
 		g.data_dir = os.path.join(g.data_dir_root,'regtest',('alice','bob')[g.bob])
 		check_or_create_dir(g.data_dir)
 		import regtest as rt
-		g.testnet = True
 		g.rpc_host = 'localhost'
 		g.rpc_port = rt.rpc_port
 		g.rpc_user = rt.rpc_user
diff --git a/mmgen/protocol.py b/mmgen/protocol.py
new file mode 100755
index 00000000..358fd633
--- /dev/null
+++ b/mmgen/protocol.py
@@ -0,0 +1,181 @@
+#!/usr/bin/env python
+#
+# MMGen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
+# Copyright (C)2013-2017 Philemon <mmgen-py@yandex.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+protocol.py: Coin protocol functions, classes and methods
+"""
+
+import os,hashlib
+from binascii import unhexlify
+from mmgen.util import msg,pmsg
+
+def hash160(hexnum): # take hex, return hex - OP_HASH160
+	return hashlib.new('ripemd160',hashlib.sha256(unhexlify(hexnum)).digest()).hexdigest()
+
+def hash256(hexnum): # take hex, return hex - OP_HASH256
+	return hashlib.sha256(hashlib.sha256(unhexlify(hexnum)).digest()).hexdigest()
+
+# From en.bitcoin.it:
+#  The Base58 encoding used is home made, and has some differences.
+#  Especially, leading zeroes are kept as single zeroes when conversion happens.
+# Test: 5JbQQTs3cnoYN9vDYaGY6nhQ1DggVsY4FJNBUfEfpSQqrEp3srk
+# The 'zero address':
+# 1111111111111111111114oLvT2 (pubkeyhash = '\0'*20)
+_b58a='123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
+
+def _numtob58(num):
+	ret = []
+	while num:
+		ret.append(_b58a[num % 58])
+		num /= 58
+	return ''.join(ret)[::-1]
+
+def _b58tonum(b58num):
+	b58num = b58num.strip()
+	for i in b58num:
+		if not i in _b58a: return False
+	return sum(_b58a.index(n) * (58**i) for i,n in enumerate(list(b58num[::-1])))
+
+def get_coin_protocol(coin,testnet):
+	coin = coin.lower()
+	coins = {
+		'btc': (BitcoinProtocol,BitcoinTestnetProtocol),
+		'bch': (BitcoinCashProtocol,BitcoinCashTestnetProtocol),
+		'ltc': (LitecoinProtocol,LitecoinTestnetProtocol),
+		'eth': (EthereumProtocol,EthereumTestnetProtocol),
+	}
+	assert type(testnet) == bool
+	assert coin in coins
+	return coins[coin][testnet]
+
+from mmgen.obj import MMGenObject
+from mmgen.globalvars import g
+
+class BitcoinProtocol(MMGenObject):
+	# devdoc/ref_transactions.md:
+	addr_ver_num         = { 'p2pkh': ('00','1'), 'p2sh':  ('05','3') }
+	addr_pfxs            = '13'
+	uncompressed_wif_pfx = '5'
+	privkey_pfx          = '80'
+	mmtypes              = ('L','C','S')
+	data_subdir          = ''
+	rpc_port             = 8332
+	daemon_data_dir = os.path.join(os.getenv('APPDATA'),'Bitcoin') if g.platform == 'win' \
+						else os.path.join(g.home_dir,'.bitcoin')
+	sighash_type = 'ALL'
+	block0 = '000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f'
+	forks = [
+		(478559,'00000000000000000019f112ec0a9982926f1258cdcc558dd7c3b7e5dc7fa148','bch')
+	]
+
+	@classmethod
+	def get_chain_protocol(cls,chain):
+		chain_protos = { 'mainnet':'', 'testnet':'Testnet', 'regtest':'Testnet' }
+		assert chain in chain_protos
+		return globals()['Bitcoin{}Protocol'.format(chain_protos[chain])]
+
+	@classmethod
+	def hex2wif(cls,hexpriv,compressed=False):
+		s = cls.privkey_pfx + hexpriv + ('','01')[bool(compressed)]
+		return _numtob58(int(s+hash256(s)[:8],16))
+
+	@classmethod
+	def wif2hex(cls,wif):
+		num = _b58tonum(wif)
+		if num == False: return False
+		key = '{:x}'.format(num)
+		compressed = wif[0] != cls.uncompressed_wif_pfx
+		klen = (66,68)[bool(compressed)]
+		if compressed and key[66:68] != '01': return False
+		if (key[:2] == cls.privkey_pfx and key[klen:] == hash256(key[:klen])[:8]):
+			return { 'hex':key[2:66], 'compressed':compressed }
+		else:
+			return False
+
+	@classmethod
+	def verify_addr(cls,addr,verbose=False,return_dict=False):
+		for addr_fmt in ('p2pkh','p2sh'):
+			ver_num,ldigit = cls.addr_ver_num[addr_fmt]
+			if addr[0] not in ldigit: continue
+			num = _b58tonum(addr)
+			if num == False: break
+			addr_hex = '{:050x}'.format(num)
+			if addr_hex[:2] != ver_num: continue
+			if hash256(addr_hex[:42])[:8] == addr_hex[42:]:
+				return { 'hex':addr_hex[2:42], 'format':addr_fmt } if return_dict else True
+			else:
+				if verbose: Msg("Invalid checksum in address '{}'".format(addr))
+				break
+		if verbose: Msg("Invalid address '{}'".format(addr))
+		return False
+
+	@classmethod
+	def hexaddr2addr(cls,hexaddr,p2sh=False):
+		s = cls.addr_ver_num[('p2pkh','p2sh')[p2sh]][0] + hexaddr
+		lzeroes = (len(s) - len(s.lstrip('0'))) / 2
+		return ('1' * lzeroes) + _numtob58(int(s+hash256(s)[:8],16))
+
+	# Segwit:
+	@classmethod
+	def pubhex2redeem_script(cls,pubhex):
+		# https://bitcoincore.org/en/segwit_wallet_dev/
+		# The P2SH redeemScript is always 22 bytes. It starts with a OP_0, followed
+		# by a canonical push of the keyhash (i.e. 0x0014{20-byte keyhash})
+		return '0014' + hash160(pubhex)
+
+	@classmethod
+	def pubhex2segwitaddr(cls,pubhex):
+		return cls.hexaddr2addr(hash160(cls.pubhex2redeem_script(pubhex)),p2sh=True)
+
+class BitcoinTestnetProtocol(BitcoinProtocol):
+	addr_ver_num         = { 'p2pkh': ('6f','mn'), 'p2sh':  ('c4','2') }
+	addr_pfxs            = 'mn2'
+	uncompressed_wif_pfx = '9'
+	privkey_pfx          = 'ef'
+	data_subdir          = 'testnet3'
+	rpc_port             = 18332
+
+class BitcoinCashProtocol(BitcoinProtocol):
+	# TODO: assumes MSWin user installs in custom dir 'Bitcoin_ABC'
+	daemon_data_dir = os.path.join(os.getenv('APPDATA'),'Bitcoin_ABC') if g.platform == 'win' \
+						else os.path.join(g.home_dir,'.bitcoin-abc')
+	rpc_port     = 8442
+	mmtypes      = ('L','C')
+	sighash_type = 'ALL|FORKID'
+	block0 = '000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f'
+	forks = [
+		(478559,'000000000000000000651ef99cb9fcbe0dadde1d424bd9f15ff20136191a5eec','btc')
+	]
+
+	@classmethod
+	def pubhex2redeem_script(cls,pubhex): raise NotImplementedError
+	@classmethod
+	def pubhex2segwitaddr(cls,pubhex):    raise NotImplementedError
+
+class BitcoinCashTestnetProtocol(BitcoinTestnetProtocol):
+	rpc_port = 18442
+	@classmethod
+	def pubhex2redeem_script(cls,pubhex): raise NotImplementedError
+	@classmethod
+	def pubhex2segwitaddr(cls,pubhex):    raise NotImplementedError
+
+class LitecoinProtocol(BitcoinProtocol): pass
+class LitecoinTestnetProtocol(LitecoinProtocol): pass
+
+class EthereumProtocol(MMGenObject): pass
+class EthereumTestnetProtocol(EthereumProtocol): pass
diff --git a/mmgen/rpc.py b/mmgen/rpc.py
index 22fd577b..83d091d1 100755
--- a/mmgen/rpc.py
+++ b/mmgen/rpc.py
@@ -163,6 +163,7 @@ class BitcoinRPCConnection(object):
 		'getnetworkinfo',
 		'getpeerinfo',
 		'getrawmempool',
+		'getmempoolentry',
 		'getrawtransaction',
 		'gettransaction',
 		'importaddress',
diff --git a/mmgen/tool.py b/mmgen/tool.py
index a9ec37db..a4db4b31 100755
--- a/mmgen/tool.py
+++ b/mmgen/tool.py
@@ -21,9 +21,9 @@
 tool.py:  Routines and data for the 'mmgen-tool' utility
 """
 
-import binascii as ba
+import binascii
 
-import mmgen.bitcoin as mmb
+from mmgen.protocol import hash160
 from mmgen.common import *
 from mmgen.crypto import *
 from mmgen.tx import *
@@ -61,8 +61,8 @@ cmd_data = OrderedDict([
 	('Wif2hex',    ['<wif> [str-]']),
 	('Wif2addr',   ['<wif> [str-]','segwit [bool=False]']),
 	('Wif2segwit_pair',['<wif> [str-]']),
-	('Hexaddr2addr', ['<btc address in hex format> [str-]']),
-	('Addr2hexaddr', ['<btc address> [str-]']),
+	('Hexaddr2addr', ['<coin address in hex format> [str-]']),
+	('Addr2hexaddr', ['<coin address> [str-]']),
 	('Privhex2addr', ['<private key in hex format> [str-]','compressed [bool=False]','segwit [bool=False]']),
 	('Privhex2pubhex',['<private key in hex format> [str-]','compressed [bool=False]']),
 	('Pubhex2addr',  ['<public key in hex format> [str-]','p2sh [bool=False]']), # new
@@ -247,7 +247,7 @@ def B58randenc():
 	print_convert_results(r,enc,dec,'str')
 
 def Randhex(nbytes='32'):
-	Msg(ba.hexlify(get_random(int(nbytes))))
+	Msg(binascii.hexlify(get_random(int(nbytes))))
 
 def Randwif(compressed=False):
 	Msg(PrivKey(get_random(32),compressed).wif)
@@ -279,21 +279,24 @@ def Wif2segwit_pair(wif):
 	rs = ag.to_segwit_redeem_script(pubhex)
 	Msg('{}\n{}'.format(rs,addr))
 
-def Hexaddr2addr(hexaddr):                     Msg(mmb.hexaddr2addr(hexaddr))
-def Addr2hexaddr(addr):                        Msg(mmb.verify_addr(addr,return_dict=True)['hex'])
-def Hash160(pubkeyhex):                        Msg(mmb.hash160(pubkeyhex))
-def Pubhex2addr(pubkeyhex,p2sh=False):         Msg(mmb.hexaddr2addr(mmb.hash160(pubkeyhex),p2sh=p2sh))
+def Hexaddr2addr(hexaddr):                     Msg(g.proto.hexaddr2addr(hexaddr))
+def Addr2hexaddr(addr):                        Msg(g.proto.verify_addr(addr,return_dict=True)['hex'])
+def Hash160(pubkeyhex):                        Msg(hash160(pubkeyhex))
+def Pubhex2addr(pubkeyhex,p2sh=False):         Msg(g.proto.hexaddr2addr(hash160(pubkeyhex),p2sh=p2sh))
 def Wif2hex(wif):                              Msg(wif2hex(wif))
 def Hex2wif(hexpriv,compressed=False):
-	Msg(mmb.hex2wif(hexpriv,compressed))
-def Privhex2addr(privhex,compressed=False,segwit=False):
+	Msg(g.proto.hex2wif(hexpriv,compressed))
+def Privhex2addr(privhex,compressed=False,segwit=False,output_pubhex=False):
 	if segwit and not compressed:
 		die(1,'Segwit address can be generated only from a compressed pubkey')
-	Msg(mmb.privnum2addr(int(privhex,16),compressed,segwit=segwit))
+	pk = PrivKey(binascii.unhexlify(privhex),compressed=compressed)
+	ph = kg.to_pubhex(pk)
+	ag = AddrGenerator(('p2pkh','segwit')[bool(segwit)])
+	Msg(ph if output_pubhex else ag.to_addr(ph))
 def Privhex2pubhex(privhex,compressed=False): # new
-	Msg(mmb.privnum2pubhex(int(privhex,16),compressed))
+	return Privhex2addr(privhex,compressed=compressed,output_pubhex=True)
 def Pubhex2redeem_script(pubhex): # new
-	Msg(mmb.pubhex2redeem_script(pubhex))
+	Msg(g.proto.pubhex2redeem_script(pubhex))
 def Wif2redeem_script(wif): # new
 	privhex = PrivKey(wif=wif)
 	if not privhex.compressed:
@@ -309,7 +312,7 @@ wordlists = 'electrum','tirosh'
 dfl_wl_id = 'electrum'
 
 def do_random_mn(nbytes,wordlist):
-	hexrand = ba.hexlify(get_random(nbytes))
+	hexrand = binascii.hexlify(get_random(nbytes))
 	Vmsg('Seed: %s' % hexrand)
 	for wl_id in ([wordlist],wordlists)[wordlist=='all']:
 		if wordlist == 'all':
@@ -324,10 +327,10 @@ def Mn_rand256(wordlist=dfl_wl_id): do_random_mn(32,wordlist)
 def Hex2mn(s,wordlist=dfl_wl_id): Msg(' '.join(baseconv.fromhex(s,wordlist)))
 def Mn2hex(s,wordlist=dfl_wl_id): Msg(baseconv.tohex(s.split(),wordlist))
 
-def Strtob58(s,pad=None): Msg(''.join(baseconv.fromhex(ba.hexlify(s),'b58',pad)))
+def Strtob58(s,pad=None): Msg(''.join(baseconv.fromhex(binascii.hexlify(s),'b58',pad)))
 def Hextob58(s,pad=None): Msg(''.join(baseconv.fromhex(s,'b58',pad)))
 def Hextob32(s,pad=None): Msg(''.join(baseconv.fromhex(s,'b32',pad)))
-def B58tostr(s):          Msg(ba.unhexlify(baseconv.tohex(s,'b58')))
+def B58tostr(s):          Msg(binascii.unhexlify(baseconv.tohex(s,'b58')))
 def B58tohex(s,pad=None): Msg(baseconv.tohex(s,'b58',pad))
 def B32tohex(s,pad=None): Msg(baseconv.tohex(s.upper(),'b32',pad))
 
@@ -403,7 +406,9 @@ def Listaddresses(addrs='',minconf=1,showempty=False,pager=False,showbtcaddrs=Tr
 					die(2,'duplicate {} address ({}) for this MMGen address! ({})'.format(
 							g.coin,d['address'],addrs[label.mmid]['addr']))
 			else:
-				addrs[label.mmid] = { 'amt':BTCAmt('0'), 'lbl':label, 'addr':BTCAddr(d['address']) }
+				addrs[label.mmid] = { 'amt':  BTCAmt('0'),
+									  'lbl':  label,
+									  'addr': CoinAddr(d['address'])}
 			addrs[label.mmid]['amt'] += d['amount']
 			total += d['amount']
 
@@ -425,7 +430,7 @@ def Listaddresses(addrs='',minconf=1,showempty=False,pager=False,showbtcaddrs=Tr
 			if label.mmid not in addrs:
 				addrs[label.mmid] = { 'amt':BTCAmt('0'), 'lbl':label, 'addr':'' }
 				if showbtcaddrs:
-					addrs[label.mmid]['addr'] = BTCAddr(addr_arr[0])
+					addrs[label.mmid]['addr'] = CoinAddr(addr_arr[0])
 
 	if not addrs:
 		die(0,('No tracked addresses with balances!','No tracked addresses!')[showempty])
@@ -438,7 +443,7 @@ def Listaddresses(addrs='',minconf=1,showempty=False,pager=False,showbtcaddrs=Tr
 	max_cmt_len =  max(max(len(addrs[k]['lbl'].comment) for k in addrs),7)
 	out += [fs.format(
 			mid=MMGenID.fmtc('MMGenID',width=max_mmid_len),
-			addr=BTCAddr.fmtc('ADDRESS'),
+			addr=CoinAddr.fmtc('ADDRESS'),
 			cmt=TwComment.fmtc('COMMENT',width=max_cmt_len),
 			amt='BALANCE'
 			)]
@@ -533,10 +538,10 @@ def Passwdfile_chksum(infile):
 	PasswordList(infile=infile,chksum_only=True)
 
 def Hexreverse(s):
-	Msg(ba.hexlify(ba.unhexlify(s.strip())[::-1]))
+	Msg(binascii.hexlify(binascii.unhexlify(s.strip())[::-1]))
 
 def Hexlify(s):
-	Msg(ba.hexlify(s))
+	Msg(binascii.hexlify(s))
 
 def Hash256(s, file_input=False, hex_input=False):
 	from hashlib import sha256
diff --git a/mmgen/tw.py b/mmgen/tw.py
index b07e810d..41cd1771 100755
--- a/mmgen/tw.py
+++ b/mmgen/tw.py
@@ -45,7 +45,7 @@ class MMGenTrackingWallet(MMGenObject):
 		amt      = MMGenImmutableAttr('amt','BTCAmt'),
 		label    = MMGenListItemAttr('label','TwComment',reassign_ok=True),
 		twmmid   = MMGenImmutableAttr('twmmid','TwMMGenID')
-		addr     = MMGenImmutableAttr('addr','BTCAddr'),
+		addr     = MMGenImmutableAttr('addr','CoinAddr'),
 		confs    = MMGenImmutableAttr('confs',int,typeconv=False),
 		scriptPubKey = MMGenImmutableAttr('scriptPubKey','HexStr')
 		days    = MMGenListItemAttr('days',int,typeconv=False),
@@ -71,9 +71,9 @@ watch-only wallet using '{}-addrimport' and then re-run this program.
 		self.get_unspent_data()
 		self.sort_key     = 'age'
 		self.do_sort()
-		self.total        = self.get_total_btc()
+		self.total        = self.get_total_coin()
 
-	def get_total_btc(self):
+	def get_total_coin(self):
 		return sum(i.amt for i in self.unspent)
 
 	def get_unspent_data(self):
@@ -95,7 +95,7 @@ watch-only wallet using '{}-addrimport' and then re-run this program.
 					'label':  l.comment,
 					'days':   int(o['confirmations'] * g.mins_per_block / (60*24)),
 					'amt':    BTCAmt(o['amount']), # TODO
-					'addr':   BTCAddr(o['address']), # TODO
+					'addr':   CoinAddr(o['address']), # TODO
 					'confs':  o['confirmations']
 				})
 				mm_rpc.append(o)
@@ -168,7 +168,7 @@ watch-only wallet using '{}-addrimport' and then re-run this program.
 		out  = [hdr_fmt.format(' '.join(self.sort_info()),g.coin,self.total.hl())]
 		if g.chain in ('testnet','regtest'):
 			out += [green('Chain: {}'.format(g.chain.upper()))]
-		af = BTCAddr.fmtc('Address',width=addr_w+1)
+		af = CoinAddr.fmtc('Address',width=addr_w+1)
 		cf = ('Conf.','Age(d)')[self.show_days]
 		out += [fs % ('Num','TX id'.ljust(tx_w - 5) + ' Vout','',af,'Amt({}) '.format(g.coin),cf)]
 
@@ -312,33 +312,33 @@ Display options: show [D]ays, [g]roup, show [m]mgen addr, r[e]draw screen
 	# returns on failure
 	@classmethod
 	def add_label(cls,arg1,label='',addr=None,silent=False):
-		from mmgen.tx import is_mmgen_id,is_btc_addr
-		mmaddr,btcaddr = None,None
-		if is_btc_addr(addr or arg1):
-			btcaddr = BTCAddr(addr or arg1,on_fail='return')
+		from mmgen.tx import is_mmgen_id,is_coin_addr
+		mmaddr,coinaddr = None,None
+		if is_coin_addr(addr or arg1):
+			coinaddr = CoinAddr(addr or arg1,on_fail='return')
 		if is_mmgen_id(arg1):
 			mmaddr = TwMMGenID(arg1)
 
-		if not btcaddr and not mmaddr:
+		if not coinaddr and not mmaddr:
 			msg("Address '{}' invalid or not found in tracking wallet".format(addr or arg1))
 			return False
 
-		if not btcaddr:
+		if not coinaddr:
 			from mmgen.addr import AddrData
-			btcaddr = AddrData(source='tw').mmaddr2btcaddr(mmaddr)
+			coinaddr = AddrData(source='tw').mmaddr2coinaddr(mmaddr)
 
-		if not btcaddr:
+		if not coinaddr:
 			msg("{} address '{}' not found in tracking wallet".format(g.proj_name,mmaddr))
 			return False
 
 		# Checked that the user isn't importing a random address
-		if not btcaddr.is_in_tracking_wallet():
-			msg("Address '{}' not in tracking wallet".format(btcaddr))
+		if not coinaddr.is_in_tracking_wallet():
+			msg("Address '{}' not in tracking wallet".format(coinaddr))
 			return False
 
 		c = rpc_connection()
-		if not btcaddr.is_for_current_chain():
-			msg("Address '{}' not valid for chain {}".format(btcaddr,g.chain.upper()))
+		if not coinaddr.is_for_current_chain():
+			msg("Address '{}' not valid for chain {}".format(coinaddr,g.chain.upper()))
 			return False
 
 		# Allow for the possibility that BTC addr of MMGen addr was entered.
@@ -346,9 +346,9 @@ Display options: show [D]ays, [g]roup, show [m]mgen addr, r[e]draw screen
 		if not mmaddr:
 			from mmgen.addr import AddrData
 			ad = AddrData(source='tw')
-			mmaddr = ad.btcaddr2mmaddr(btcaddr)
+			mmaddr = ad.coinaddr2mmaddr(coinaddr)
 
-		if not mmaddr: mmaddr = 'btc:'+btcaddr
+		if not mmaddr: mmaddr = 'btc:'+coinaddr
 
 		mmaddr = TwMMGenID(mmaddr)
 
@@ -361,7 +361,7 @@ Display options: show [D]ays, [g]roup, show [m]mgen addr, r[e]draw screen
 		# associating the new account with the address.
 		# Will be replaced by setlabel() with new RPC label API
 		# RPC args: addr,label,rescan[=true],p2sh[=none]
-		ret = c.importaddress(btcaddr,lbl,False,on_fail='return')
+		ret = c.importaddress(coinaddr,lbl,False,on_fail='return')
 
 		from mmgen.rpc import rpc_error,rpc_errmsg
 		if rpc_error(ret):
diff --git a/mmgen/tx.py b/mmgen/tx.py
index f655bf9b..4e6115e9 100755
--- a/mmgen/tx.py
+++ b/mmgen/tx.py
@@ -118,7 +118,7 @@ txio_attrs = {
 	'amt':   MMGenImmutableAttr('amt','BTCAmt'),
 	'label': MMGenListItemAttr('label','TwComment',reassign_ok=True),
 	'mmid':  MMGenListItemAttr('mmid','MMGenID'),
-	'addr':  MMGenImmutableAttr('addr','BTCAddr'),
+	'addr':  MMGenImmutableAttr('addr','CoinAddr'),
 	'confs': MMGenListItemAttr('confs',int,typeconv=True), # long confs exist in the wild, so convert
 	'txid':  MMGenListItemAttr('txid','BitcoinTxID'),
 	'have_wif': MMGenListItemAttr('have_wif',bool,typeconv=False,delete_ok=True)
@@ -150,7 +150,7 @@ class MMGenTX(MMGenObject):
 		self.hex         = ''           # raw serialized hex transaction
 		self.label       = MMGenTXLabel('')
 		self.txid        = ''
-		self.btc_txid    = ''
+		self.coin_txid    = ''
 		self.timestamp   = ''
 		self.chksum      = ''
 		self.fmt_data    = ''
@@ -168,8 +168,8 @@ class MMGenTX(MMGenObject):
 		if self.chain and g.chain and self.chain != g.chain:
 			die(2,'Transaction is for {}, but current chain is {}!'.format(self.chain,g.chain))
 
-	def add_output(self,btcaddr,amt,is_chg=None):
-		self.outputs.append(self.MMGenTxOutput(addr=btcaddr,amt=amt,is_chg=is_chg))
+	def add_output(self,coinaddr,amt,is_chg=None):
+		self.outputs.append(self.MMGenTxOutput(addr=coinaddr,amt=amt,is_chg=is_chg))
 
 	def get_chg_output_idx(self):
 		for i in range(len(self.outputs)):
@@ -302,8 +302,8 @@ class MMGenTX(MMGenObject):
 	def get_fee(self):
 		return self.sum_inputs() - self.sum_outputs()
 
-	def btc2spb(self,btc_fee):
-		return int(btc_fee/g.satoshi/self.estimate_size())
+	def btc2spb(self,coin_fee):
+		return int(coin_fee/g.satoshi/self.estimate_size())
 
 	def get_relay_fee(self):
 		assert self.estimate_size()
@@ -326,38 +326,38 @@ class MMGenTX(MMGenObject):
 				assert False, "'{}': invalid tx-fee argument".format(tx_fee)
 
 	def get_usr_fee(self,tx_fee,desc='Missing description'):
-		btc_fee = self.convert_fee_spec(tx_fee,self.estimate_size(),on_fail='return')
-		if btc_fee == None:
+		coin_fee = self.convert_fee_spec(tx_fee,self.estimate_size(),on_fail='return')
+		if coin_fee == None:
 			# we shouldn't be calling this if tx size is unknown
 			m = "'{}': cannot convert satoshis-per-byte to {} because transaction size is unknown"
 			assert False, m.format(tx_fee,g.coin)
-		elif btc_fee == False:
+		elif coin_fee == False:
 			m = "'{}': invalid TX fee (not a {} amount or satoshis-per-byte specification)"
 			msg(m.format(tx_fee,g.coin))
 			return False
-		elif btc_fee > g.max_tx_fee:
+		elif coin_fee > g.max_tx_fee:
 			m = '{} {c}: {} fee too large (maximum fee: {} {c})'
-			msg(m.format(btc_fee,desc,g.max_tx_fee,c=g.coin))
+			msg(m.format(coin_fee,desc,g.max_tx_fee,c=g.coin))
 			return False
-		elif btc_fee < self.get_relay_fee():
+		elif coin_fee < self.get_relay_fee():
 			m = '{} {c}: {} fee too small (below relay fee of {} {c})'
-			msg(m.format(str(btc_fee),desc,str(self.get_relay_fee()),c=g.coin))
+			msg(m.format(str(coin_fee),desc,str(self.get_relay_fee()),c=g.coin))
 			return False
 		else:
-			return btc_fee
+			return coin_fee
 
 	def get_usr_fee_interactive(self,tx_fee=None,desc='Starting'):
-		btc_fee = None
+		coin_fee = None
 		while True:
 			if tx_fee:
-				btc_fee = self.get_usr_fee(tx_fee,desc)
-			if btc_fee:
+				coin_fee = self.get_usr_fee(tx_fee,desc)
+			if coin_fee:
 				m = ('',' (after {}x adjustment)'.format(opt.tx_fee_adj))[opt.tx_fee_adj != 1]
 				p = '{} TX fee{}: {} {} ({} satoshis per byte)'.format(desc,m,
-					btc_fee.hl(),g.coin,pink(str(self.btc2spb(btc_fee))))
+					coin_fee.hl(),g.coin,pink(str(self.btc2spb(coin_fee))))
 				if opt.yes or keypress_confirm(p+'.  OK?',default_yes=True):
 					if opt.yes: msg(p)
-					return btc_fee
+					return coin_fee
 			tx_fee = my_raw_input('Enter transaction fee: ')
 			desc = 'User-selected'
 
@@ -420,9 +420,9 @@ class MMGenTX(MMGenObject):
 		]
 		if self.label:
 			lines.append(baseconv.b58encode(self.label.encode('utf8')))
-		if self.btc_txid:
+		if self.coin_txid:
 			if not self.label: lines.append('-') # keep old tx files backwards compatible
-			lines.append(self.btc_txid)
+			lines.append(self.coin_txid)
 		self.chksum = make_chksum_6(' '.join(lines))
 		self.fmt_data = '\n'.join([self.chksum] + lines)+'\n'
 
@@ -455,11 +455,10 @@ class MMGenTX(MMGenObject):
 			sig_data.append(e)
 
 		msg_r('Signing transaction{}...'.format(tx_num_str))
-		ht = ('ALL','ALL|FORKID')[g.coin=='BCH'] # sighashtype defaults to 'ALL'
 		wifs = [d.sec.wif for d in keys]
 #		keys.pmsg()
 #		pmsg(wifs)
-		ret = c.signrawtransaction(self.hex,sig_data,wifs,ht,on_fail='return')
+		ret = c.signrawtransaction(self.hex,sig_data,wifs,g.proto.sighash_type,on_fail='return')
 
 		from mmgen.rpc import rpc_error,rpc_errmsg
 		if rpc_error(ret):
@@ -479,7 +478,7 @@ class MMGenTX(MMGenObject):
 				txid = dt['txid']
 				self.check_sigs(dt)
 				assert txid == c.decoderawtransaction(self.hex)['txid'], 'txid mismatch (after signing)'
-				self.btc_txid = BitcoinTxID(txid,on_fail='return')
+				self.coin_txid = BitcoinTxID(txid,on_fail='return')
 				msg('OK')
 				return True
 			else:
@@ -523,10 +522,10 @@ class MMGenTX(MMGenObject):
 		return any(o.mmid and o.mmid.mmtype == 'S' for o in self.outputs)
 
 	def is_in_mempool(self,c):
-		return 'size' in c.getmempoolentry(self.btc_txid,on_fail='silent')
+		return 'size' in c.getmempoolentry(self.coin_txid,on_fail='silent')
 
 	def is_in_wallet(self,c):
-		ret = c.gettransaction(self.btc_txid,on_fail='silent')
+		ret = c.gettransaction(self.coin_txid,on_fail='silent')
 		if 'confirmations' in ret and ret['confirmations'] > 0:
 			return ret['confirmations']
 		else:
@@ -534,13 +533,13 @@ class MMGenTX(MMGenObject):
 
 	def is_replaced(self,c):
 		if self.is_in_mempool(c): return False
-		ret = c.gettransaction(self.btc_txid,on_fail='silent')
+		ret = c.gettransaction(self.coin_txid,on_fail='silent')
 		if not 'bip125-replaceable' in ret or not 'confirmations' in ret or ret['confirmations'] > 0:
 			return False
 		return -ret['confirmations'] + 1 # 1: replacement in mempool, 2: replacement confirmed
 
 	def is_in_utxos(self,c):
-		return 'txid' in c.getrawtransaction(self.btc_txid,True,on_fail='silent')
+		return 'txid' in c.getrawtransaction(self.coin_txid,True,on_fail='silent')
 
 	def get_status(self,c,status=False):
 		if self.is_in_mempool(c):
@@ -596,17 +595,17 @@ class MMGenTX(MMGenObject):
 			if bogus_send:
 				m = 'BOGUS transaction NOT sent: {}'
 			else:
-				assert ret == self.btc_txid, 'txid mismatch (after sending)'
+				assert ret == self.coin_txid, 'txid mismatch (after sending)'
 				m = 'Transaction sent: {}'
 			self.desc = 'sent transaction'
-			msg(m.format(self.btc_txid.hl()))
+			msg(m.format(self.coin_txid.hl()))
 			self.add_timestamp()
 			self.add_blockcount(c)
 			return True
 
 	def write_txid_to_file(self,ask_write=False,ask_write_default_yes=True):
 		fn = '%s[%s].%s' % (self.txid,self.send_amt,self.txid_ext)
-		write_data_to_file(fn,self.btc_txid+'\n','transaction ID',
+		write_data_to_file(fn,self.coin_txid+'\n','transaction ID',
 			ask_write=ask_write,
 			ask_write_default_yes=ask_write_default_yes)
 
@@ -704,8 +703,8 @@ class MMGenTX(MMGenObject):
 				self.is_rbf(color=True),self.marked_signed(color=True))
 		if self.chain in ('testnet','regtest'):
 			out += green('Chain: {}\n'.format(self.chain.upper()))
-		if self.btc_txid:
-			out += '{} TxID: {}\n'.format(g.coin,self.btc_txid.hl())
+		if self.coin_txid:
+			out += '{} TxID: {}\n'.format(g.coin,self.coin_txid.hl())
 		enl = ('\n','')[bool(terse)]
 		out += enl
 		if self.label:
@@ -747,8 +746,8 @@ class MMGenTX(MMGenObject):
 			do_err('checksum')
 
 		if len(tx_data) == 6:
-			self.btc_txid = BitcoinTxID(tx_data.pop(-1),on_fail='return')
-			if not self.btc_txid:
+			self.coin_txid = BitcoinTxID(tx_data.pop(-1),on_fail='return')
+			if not self.coin_txid:
 				do_err('Bitcoin TxID')
 
 		if len(tx_data) == 5:
@@ -787,7 +786,7 @@ class MMGenTX(MMGenObject):
 		try: self.inputs = self.decode_io('inputs',eval(inputs_data))
 		except: do_err('inputs data')
 
-		if not self.chain and not self.inputs[0].addr.testnet:
+		if not self.chain and not self.inputs[0].addr.is_testnet():
 			self.chain = 'mainnet'
 
 		try: self.outputs = self.decode_io('outputs',eval(outputs_data))
@@ -809,10 +808,10 @@ class MMGenBumpTX(MMGenTX):
 		if send:
 			if not self.marked_signed():
 				die(1,"File '{}' is not a signed {} transaction file".format(filename,g.proj_name))
-			if not self.btc_txid:
+			if not self.coin_txid:
 				die(1,"Transaction '{}' was not broadcast to the network".format(self.txid,g.proj_name))
 
-		self.btc_txid = ''
+		self.coin_txid = ''
 		self.mark_raw()
 
 	def choose_output(self):
diff --git a/mmgen/txcreate.py b/mmgen/txcreate.py
index 185dad83..b58d7989 100755
--- a/mmgen/txcreate.py
+++ b/mmgen/txcreate.py
@@ -54,7 +54,7 @@ FEE SPECIFICATION: Transaction fees, both on the command line and at the
 interactive prompt, may be specified as either absolute {} amounts, using
 a plain decimal number, or as satoshis per byte, using an integer followed by
 the letter 's'.
-""" # formatted later, after g.coin is initialized
+"""
 
 wmsg = {
 	'addr_in_addrfile_only': """
@@ -79,7 +79,7 @@ inputs must be supplied to '{pnl}-txsign' in a file with the '--keys-from-file'
 option.
 Selected non-{pnm} inputs: {{}}
 """.strip().format(pnm=pnm,pnl=pnm.lower()),
-	'not_enough_btc': """
+	'not_enough_coin': """
 Selected outputs insufficient to fund this transaction ({{}} {} needed)
 """.strip().format(g.coin),
 	'no_change_output': """
@@ -98,15 +98,15 @@ def select_unspent(unspent,prompt):
 					return selected
 				msg('Unspent output number must be <= %s' % len(unspent))
 
-def mmaddr2baddr(c,mmaddr,ad_w,ad_f):
+def mmaddr2coinaddr(c,mmaddr,ad_w,ad_f):
 
 	# assume mmaddr has already been checked
-	btc_addr = ad_w.mmaddr2btcaddr(mmaddr)
+	coin_addr = ad_w.mmaddr2coinaddr(mmaddr)
 
-	if not btc_addr:
+	if not coin_addr:
 		if ad_f:
-			btc_addr = ad_f.mmaddr2btcaddr(mmaddr)
-			if btc_addr:
+			coin_addr = ad_f.mmaddr2coinaddr(mmaddr)
+			if coin_addr:
 				msg(wmsg['addr_in_addrfile_only'].format(mmgenaddr=mmaddr))
 				if not keypress_confirm('Continue anyway?'):
 					sys.exit(1)
@@ -115,7 +115,7 @@ def mmaddr2baddr(c,mmaddr,ad_w,ad_f):
 		else:
 			die(2,wmsg['addr_not_found_no_addrfile'].format(pnm=pnm,mmgenaddr=mmaddr))
 
-	return BTCAddr(btc_addr)
+	return CoinAddr(coin_addr)
 
 def get_fee_from_estimate_or_user(tx,estimate_fail_msg_shown=[]):
 
@@ -155,16 +155,16 @@ def get_outputs_from_cmdline(cmd_args,tx):
 	for a in cmd_args:
 		if ',' in a:
 			a1,a2 = a.split(',',1)
-			if is_mmgen_id(a1) or is_btc_addr(a1):
-				btc_addr = mmaddr2baddr(c,a1,ad_w,ad_f) if is_mmgen_id(a1) else BTCAddr(a1)
-				tx.add_output(btc_addr,BTCAmt(a2))
+			if is_mmgen_id(a1) or is_coin_addr(a1):
+				coin_addr = mmaddr2coinaddr(c,a1,ad_w,ad_f) if is_mmgen_id(a1) else CoinAddr(a1)
+				tx.add_output(coin_addr,BTCAmt(a2))
 			else:
 				die(2,"%s: unrecognized subargument in argument '%s'" % (a1,a))
-		elif is_mmgen_id(a) or is_btc_addr(a):
+		elif is_mmgen_id(a) or is_coin_addr(a):
 			if tx.get_chg_output_idx() != None:
 				die(2,'ERROR: More than one change address listed on command line')
-			btc_addr = mmaddr2baddr(c,a,ad_w,ad_f) if is_mmgen_id(a) else BTCAddr(a)
-			tx.add_output(btc_addr,BTCAmt('0'),is_chg=True)
+			coin_addr = mmaddr2coinaddr(c,a,ad_w,ad_f) if is_mmgen_id(a) else CoinAddr(a)
+			tx.add_output(coin_addr,BTCAmt('0'),is_chg=True)
 		else:
 			die(2,'%s: unrecognized argument' % a)
 
@@ -191,7 +191,7 @@ def get_inputs_from_user(tw,tx,caller):
 
 		t_inputs = sum(s.amt for s in sel_unspent)
 		if t_inputs < tx.send_amt:
-			msg(wmsg['not_enough_btc'].format(tx.send_amt-t_inputs))
+			msg(wmsg['not_enough_coin'].format(tx.send_amt-t_inputs))
 			continue
 
 		non_mmaddrs = [i for i in sel_unspent if i.twmmid.type == 'non-mmgen']
@@ -210,7 +210,7 @@ def get_inputs_from_user(tw,tx,caller):
 				if opt.yes: msg(p)
 				return change_amt
 		else:
-			msg(wmsg['not_enough_btc'].format(abs(change_amt)))
+			msg(wmsg['not_enough_coin'].format(abs(change_amt)))
 
 def txcreate(cmd_args,do_info=False,caller='txcreate'):
 
diff --git a/mmgen/util.py b/mmgen/util.py
index ccb391ef..89730780 100755
--- a/mmgen/util.py
+++ b/mmgen/util.py
@@ -516,8 +516,6 @@ def confirm_or_exit(message,question,expect='YES',exit_msg='Exiting at user requ
 	if my_raw_input(a+b).strip() != expect:
 		die(1,exit_msg)
 
-
-# New function
 def write_data_to_file(
 		outfile,
 		data,
@@ -781,7 +779,7 @@ def do_license_msg(immed=False):
 
 def get_bitcoind_cfg_options(cfg_keys):
 
-	cfg_file = os.path.join(g.bitcoin_data_dir,'bitcoin.conf')
+	cfg_file = os.path.join(g.daemon_data_dir,'bitcoin.conf')
 
 	cfg = dict([(k,v) for k,v in [split2(str(line).translate(None,'\t '),'=')
 			for line in get_lines_from_file(cfg_file,'')] if k in cfg_keys]) \
@@ -792,39 +790,37 @@ def get_bitcoind_cfg_options(cfg_keys):
 	return cfg
 
 def get_bitcoind_auth_cookie():
-	f = os.path.join(g.bitcoin_data_dir,('',g.testnet_name)[g.testnet],'.cookie')
+	f = os.path.join(g.daemon_data_dir,g.proto.data_subdir,'.cookie')
 	return get_lines_from_file(f,'')[0] if file_is_readable(f) else ''
 
 def rpc_connection():
 
-	def check_coin_mismatch(c):
-		if c.getblockcount() == 0:
-			msg('Warning: no blockchain, so skipping block mismatch check')
-			return
-		fb = '00000000000000000019f112ec0a9982926f1258cdcc558dd7c3b7e5dc7fa148'
-		err = []
-		if c.getblockchaininfo()['blocks'] <= 478558 or c.getblockhash(478559) == fb:
-			if g.coin == 'BCH': err = 'BCH','BTC'
-		elif g.coin == 'BTC': err = 'BTC','BCH'
-		if err: ydie(2,"'{}' requested, but this is the {} chain!".format(*err))
+	def check_chainfork_mismatch(c):
+		block0 = c.getblockhash(0)
+		latest = c.getblockcount()
+		try:
+			assert block0 == g.proto.block0,'Incorrect Genesis block for {}'.format(g.proto.__name__)
+			for fork in g.proto.forks:
+				if latest < fork[0]: break
+				bhash = c.getblockhash(fork[0])
+				assert bhash == fork[1], (
+					'Bad block hash at fork block {}. Is this the {} chain?'.format(fork[0],fork[2].upper()))
+		except Exception as e:
+			die(2,"{}\n'{c}' requested, but this is not the {c} chain!".format(e,c=g.coin))
 
-	def check_chain_mismatch():
-		err = None
-		if g.regtest and g.chain != 'regtest':
-			err = '--regtest option'
-		elif g.testnet and g.chain == 'mainnet':
-			err = '--testnet option'
-		# we won't actually get here, as connect will fail first
-		elif (not g.testnet) and g.chain != 'mainnet':
-			err = 'mainnet'
-		if err:
-			die(1,'{} selected but chain is {}'.format(err,g.chain))
+	def check_chaintype_mismatch():
+		try:
+			if g.regtest: assert g.chain == 'regtest','--regtest option selected, but chain is not regtest'
+			if g.testnet: assert g.chain != 'mainnet','--testnet option selected, but chain is mainnet'
+			if not g.testnet: assert g.chain == 'mainnet','mainnet selected, but chain is not mainnet'
+		except Exception as e:
+			die(1,'{}\nChain is {}!'.format(e,g.chain))
 
 	cfg = get_bitcoind_cfg_options(('rpcuser','rpcpassword'))
 	import mmgen.rpc
 	c = mmgen.rpc.BitcoinRPCConnection(
 				g.rpc_host or 'localhost',
-				g.rpc_port or g.ports[g.coin][g.testnet],
+				g.rpc_port or g.proto.rpc_port,
 				g.rpc_user or cfg['rpcuser'], # MMGen's rpcuser,rpcpassword override bitcoind's
 				g.rpc_password or cfg['rpcpassword'],
 				auth_cookie=get_bitcoind_auth_cookie())
@@ -835,9 +831,9 @@ def rpc_connection():
 			rt.user(('alice','bob')[g.bob],quiet=True)
 		g.bitcoind_version = int(c.getnetworkinfo()['version'])
 		g.chain = c.getblockchaininfo()['chain']
-		if g.chain != 'regtest':
-			g.chain += 'net'
+		if g.chain != 'regtest': g.chain += 'net'
 		assert g.chain in g.chains
+		check_chaintype_mismatch()
 		if g.chain == 'mainnet':
-			check_coin_mismatch(c)
+			check_chainfork_mismatch(c)
 	return c
diff --git a/scripts/test-release.sh b/scripts/test-release.sh
index 4ab00114..8115778f 100755
--- a/scripts/test-release.sh
+++ b/scripts/test-release.sh
@@ -13,9 +13,9 @@ do
 		echo   "           '-t'  Print the tests without running them"
 		echo   "  AVAILABLE TESTS:"
 		echo   "     1 - main"
-		echo   "     2 - regtest"
-		echo   "     3 - tool"
-		echo   "     4 - gen"
+		echo   "     2 - tooltest"
+		echo   "     3 - gentest"
+		echo   "     4 - regtest"
 		echo   "  By default, all tests are run"
 		exit ;;
 	i)  INSTALL_ONLY=1 ;;
@@ -67,15 +67,16 @@ function do_test {
 
 T1=('test/test.py -On'
 	'test/test.py -On --segwit dfl_wallet main ref ref_other'
+	'test/test.py -On --coin=bch dfl_wallet main ref ref_other'
 	'test/test.py -On --segwit-random dfl_wallet main')
-T2=('test/test.py -On regtest')
-T3=('test/tooltest.py') # tooltest tests both segwit and non-segwit
-T4=("test/gentest.py -q 2 $REFDIR/btcwallet.dump"
+T2=('test/tooltest.py' 'test/tooltest.py --testnet=1') # tooltest tests both segwit and non-segwit
+T3=("test/gentest.py -q 2 $REFDIR/btcwallet.dump"
 	"test/gentest.py -q --testnet=1 2 $REFDIR/btcwallet-testnet.dump"
 	'test/gentest.py -q 1:2 10'
 	'test/gentest.py -q --segwit 1:2 10'
 #	"scripts/tx-old2new.py -S $REFDIR/tx_*raw >/dev/null 2>&1"
 	"scripts/compute-file-chksum.py $REFDIR/*testnet.rawtx >/dev/null 2>&1")
+T4=('test/test.py -On regtest')
 
 [ -d .git -a -z "$NO_INSTALL"  -a -z "$TESTING" ] && {
 	check
@@ -84,9 +85,26 @@ T4=("test/gentest.py -q 2 $REFDIR/btcwallet.dump"
 }
 [ "$INSTALL_ONLY" ] && exit
 
-if [ "$*" ]; then TESTS=$@; else TESTS='1 2 3 4'; fi
-for t in $TESTS; do
-	[ $t == 4 ] && LS=''
-	eval "do_test \"\${T$t[@]}\""
-done
+function run_tests {
+	for t in $1; do
+		[ $t == 4 ] && LS=''
+		eval "do_test \"\${T$t[@]}\""
+	done
+}
+
+if [ "$*" ]; then
+	run_tests "$*"
+else
+	echo 'Bitcoin and Bitcoin ABC must both be running for the following tests'
+	echo 'The bitcoin-abc daemon must be listening on RPC port 8442 (-rpcport 8442)'
+	echo -n 'Hit ENTER to continue: '; read
+	run_tests '1'
+	echo 'The bitcoin (mainnet) and testnet daemons must both be running for the following tests'
+	echo -n 'Hit ENTER to continue: '; read
+	run_tests '2 3'
+	echo 'You may stop the mainnet and testnet daemons now'
+	echo -n 'Hit ENTER to continue: '; read
+	run_tests '4'
+fi
+
 echo -e "$LS${GREEN}All OK$RESET"
diff --git a/setup.py b/setup.py
index d2b699eb..39f184d5 100755
--- a/setup.py
+++ b/setup.py
@@ -109,7 +109,7 @@ setup(
 		py_modules = [
 			'mmgen.__init__',
 			'mmgen.addr',
-			'mmgen.bitcoin',
+			'mmgen.protocol',
 			'mmgen.color',
 			'mmgen.common',
 			'mmgen.crypto',
diff --git a/test/mmgen_pexpect.py b/test/mmgen_pexpect.py
index 85fd7f5b..db798b6a 100755
--- a/test/mmgen_pexpect.py
+++ b/test/mmgen_pexpect.py
@@ -92,15 +92,11 @@ class MMGenPexpect(object):
 		atexit.register(lambda: os.system('stty sane'))
 		NL = '\n'
 
-	data_dir = os.path.join('test','data_dir')
-	add_spawn_args = ' '.join(['{} {}'.format('--'+k.replace('_','-'),
-		getattr(opt,k) if getattr(opt,k) != True else ''
-		) for k in ('testnet','rpc_host','rpc_port','regtest','coin') if getattr(opt,k)]).split()
-	add_spawn_args += ['--data-dir',data_dir]
-
-	def __init__(self,name,mmgen_cmd,cmd_args,desc,no_output=False):
-
-		cmd_args = self.add_spawn_args + cmd_args
+	def __init__(self,name,mmgen_cmd,cmd_args,desc,no_output=False,passthru_args=[]):
+		cmd_args = ['--{}{}'.format(k.replace('_','-'),
+			'='+getattr(opt,k) if getattr(opt,k) != True else ''
+			) for k in passthru_args if getattr(opt,k)] \
+			+ ['--data-dir='+os.path.join('test','data_dir')] + cmd_args
 		cmd = (('./','')[bool(opt.system)]+mmgen_cmd,'python')[g.platform=='win']
 		args = (cmd_args,[mmgen_cmd]+cmd_args)[g.platform=='win']
 
diff --git a/test/test.py b/test/test.py
index b747b490..20cca85d 100755
--- a/test/test.py
+++ b/test/test.py
@@ -29,6 +29,7 @@ sys.path.__setitem__(0,os.path.abspath(os.curdir))
 # Import these _after_ local path's been added to sys.path
 from mmgen.common import *
 from mmgen.test import *
+from mmgen.protocol import get_coin_protocol
 
 g.quiet = False # if 'quiet' was set in config file, disable here
 os.environ['MMGEN_QUIET'] = '0' # and for the spawned scripts
@@ -41,7 +42,7 @@ hincog_offset  = 98765
 hincog_seedlen = 256
 
 incog_id_fn  = 'incog_id'
-non_mmgen_fn = 'btckey'
+non_mmgen_fn = 'coinkey'
 pwfile = 'passwd_file'
 
 ref_dir = os.path.join('test','ref')
@@ -147,6 +148,9 @@ sys.argv = [sys.argv[0]] + ['--data-dir',data_dir] + sys.argv[1:]
 cmd_args = opts.init(opts_data)
 opt.popen_spawn = True # popen has issues, so use popen_spawn always
 
+if opt.segwit and 'S' not in g.proto.mmtypes:
+	die(1,'--segwit option incompatible with {}'.format(g.proto.__name__))
+
 tn_desc = ('','.testnet')[g.testnet]
 
 def randbool():
@@ -794,22 +798,23 @@ def verify_checksum_or_exit(checksum,chk):
 
 from test.mmgen_pexpect import MMGenPexpect
 class MMGenExpect(MMGenPexpect):
-
 	def __init__(self,name,mmgen_cmd,cmd_args=[],extra_desc='',no_output=False):
 		desc = (cmd_data[name][1],name)[bool(opt.names)] + (' ' + extra_desc).strip()
-		return MMGenPexpect.__init__(self,name,mmgen_cmd,cmd_args,desc,no_output=no_output)
+		pa = ['testnet','rpc_host','rpc_port','regtest','coin']
+		return MMGenPexpect.__init__(self,name,mmgen_cmd,cmd_args,desc,no_output=no_output,passthru_args=pa)
 
-def create_fake_unspent_entry(btcaddr,al_id=None,idx=None,lbl=None,non_mmgen=False,segwit=False):
+def create_fake_unspent_entry(coinaddr,al_id=None,idx=None,lbl=None,non_mmgen=False,segwit=False):
+	if 'S' not in g.proto.mmtypes: segwit = False
 	if lbl: lbl = ' ' + lbl
-	spk1,spk2 = (('76a914','88ac'),('a914','87'))[segwit and btcaddr.addr_fmt=='p2sh']
+	spk1,spk2 = (('76a914','88ac'),('a914','87'))[segwit and coinaddr.addr_fmt=='p2sh']
 	return {
-		'account': 'btc:{}'.format(btcaddr) if non_mmgen else (u'{}:{}{}'.format(al_id,idx,lbl.decode('utf8'))),
+		'account': 'btc:{}'.format(coinaddr) if non_mmgen else (u'{}:{}{}'.format(al_id,idx,lbl.decode('utf8'))),
 		'vout': int(getrandnum(4) % 8),
 		'txid': hexlify(os.urandom(32)).decode('utf8'),
 		'amount': BTCAmt('%s.%s' % (10+(getrandnum(4) % 40), getrandnum(4) % 100000000)),
-		'address': btcaddr,
+		'address': coinaddr,
 		'spendable': False,
-		'scriptPubKey': '{}{}{}'.format(spk1,btcaddr.hex,spk2),
+		'scriptPubKey': '{}{}{}'.format(spk1,coinaddr.hex,spk2),
 		'confirmations': getrandnum(4) % 50000
 	}
 
@@ -842,21 +847,21 @@ def create_fake_unspent_data(adata,tx_data,non_mmgen_input=''):
 	out = []
 	for d in tx_data.values():
 		al = adata.addrlist(d['al_id'])
-		for n,(idx,btcaddr) in enumerate(al.addrpairs()):
+		for n,(idx,coinaddr) in enumerate(al.addrpairs()):
 			while True:
 				try: lbl = next(label_iter)
 				except: label_iter = iter(labels)
 				else: break
-			out.append(create_fake_unspent_entry(btcaddr,d['al_id'],idx,lbl,segwit=d['segwit']))
+			out.append(create_fake_unspent_entry(coinaddr,d['al_id'],idx,lbl,segwit=d['segwit']))
 			if n == 0:  # create a duplicate address. This means addrs_per_wallet += 1
-				out.append(create_fake_unspent_entry(btcaddr,d['al_id'],idx,lbl,segwit=d['segwit']))
+				out.append(create_fake_unspent_entry(coinaddr,d['al_id'],idx,lbl,segwit=d['segwit']))
 
 	if non_mmgen_input:
 		privkey = PrivKey(os.urandom(32),compressed=True)
-		btcaddr = AddrGenerator('p2pkh').to_addr(KeyGenerator().to_pubhex(privkey))
+		coinaddr = AddrGenerator('p2pkh').to_addr(KeyGenerator().to_pubhex(privkey))
 		of = os.path.join(cfgs[non_mmgen_input]['tmpdir'],non_mmgen_fn)
 		write_data_to_file(of,privkey.wif+'\n','compressed bitcoin key',silent=True)
-		out.append(create_fake_unspent_entry(btcaddr,non_mmgen=True,segwit=False))
+		out.append(create_fake_unspent_entry(coinaddr,non_mmgen=True,segwit=False))
 
 #	msg('\n'.join([repr(o) for o in out])); sys.exit(0)
 	return out
@@ -893,7 +898,8 @@ def create_tx_data(sources):
 
 def make_txcreate_cmdline(tx_data):
 	privkey = PrivKey(os.urandom(32),compressed=True)
-	btcaddr = AddrGenerator('segwit').to_addr(KeyGenerator().to_pubhex(privkey))
+	t = ('p2pkh','segwit')['S' in g.proto.mmtypes]
+	coinaddr = AddrGenerator(t).to_addr(KeyGenerator().to_pubhex(privkey))
 
 	cmd_args = ['-d',cfg['tmpdir']]
 	for num in tx_data:
@@ -904,7 +910,7 @@ def make_txcreate_cmdline(tx_data):
 		# + one change address and one BTC address
 		if num is tx_data.keys()[-1]:
 			cmd_args += ['{}:{}'.format(s['al_id'],s['addr_idxs'][1])]
-			cmd_args += ['{},{}'.format(btcaddr,cfgs[num]['amts'][1])]
+			cmd_args += ['{},{}'.format(coinaddr,cfgs[num]['amts'][1])]
 
 	return cmd_args + [tx_data[num]['addrfile'] for num in tx_data]
 
@@ -1933,10 +1939,8 @@ class MMGenTestSuite(object):
 	def regtest_addrimport_alice(self,name): self.regtest_addrimport(name,'alice')
 
 	def regtest_fund_wallet(self,name,user,mmtype,amt):
-		fn = get_file_with_ext('-{}[1-5].addrs'.format(mmtype),self.regtest_user_dir(user),no_dot=True)
-		silence()
-		addr = AddrList(fn).data[0].addr
-		end_silence()
+		sid = self.regtest_user_sid(user)
+		addr = self.get_addr_from_regtest_addrlist(user,sid,mmtype,0)
 		t = MMGenExpect(name,'mmgen-regtest', ['send',str(addr),str(amt)])
 		t.expect('Sending {} BTC'.format(amt))
 		t.expect('Mined 1 block')
@@ -2004,23 +2008,27 @@ class MMGenTestSuite(object):
 		outputs_cl = [sid+':C:1,100', sid+':L:2,200',sid+':S:2']
 		return self.regtest_user_txdo(name,'bob','20s',outputs_cl,'1')
 
+	def get_addr_from_regtest_addrlist(self,user,sid,mmtype,idx):
+		id_str = { 'L':'', 'S':'-S', 'C':'-C' }[mmtype]
+		fn = get_file_with_ext('{}{}[1-5].addrs'.format(sid,id_str),self.regtest_user_dir(user),no_dot=True)
+		silence()
+		g.proto = get_coin_protocol(g.coin,True)
+		addr = AddrList(fn).data[idx].addr
+		g.proto = get_coin_protocol(g.coin,g.testnet)
+		end_silence()
+		return addr
+
 	def create_tx_outputs(self,user,data):
-		o,sid = [],self.regtest_user_sid(user)
-		for id_str,idx,amt_str in data:
-			fn = get_file_with_ext('{}{}[1-5].addrs'.format(sid,id_str),self.regtest_user_dir(user),no_dot=True)
-			silence()
-			addr = AddrList(fn).data[idx-1].addr
-			end_silence()
-			o.append(addr+amt_str)
-		return o
+		sid = self.regtest_user_sid(user)
+		return [self.get_addr_from_regtest_addrlist(user,sid,mmtype,idx-1)+amt_str for mmtype,idx,amt_str in data]
 
 	def regtest_bob_rbf_send(self,name):
-		outputs_cl = self.create_tx_outputs('alice',(('',1,',60'),('-C',1,',40'))) # alice_sid:L:1, alice_sid:C:1
+		outputs_cl = self.create_tx_outputs('alice',(('L',1,',60'),('C',1,',40'))) # alice_sid:L:1, alice_sid:C:1
 		outputs_cl += [self.regtest_user_sid('bob')+':S:2']
 		return self.regtest_user_txdo(name,'bob','10s',outputs_cl,'3',extra_args=['--rbf'])
 
 	def regtest_bob_send_non_mmgen(self,name):
-		outputs_cl = self.create_tx_outputs('alice',(('-S',2,',10'),('-S',3,''))) # alice_sid:S:2, alice_sid:S:3
+		outputs_cl = self.create_tx_outputs('alice',(('S',2,',10'),('S',3,''))) # alice_sid:S:2, alice_sid:S:3
 		fn = os.path.join(cfg['tmpdir'],'non-mmgen.keys')
 		return self.regtest_user_txdo(name,'bob','0.0001',outputs_cl,'3-9',extra_args=['--keys-from-file='+fn])
 
diff --git a/test/tooltest.py b/test/tooltest.py
index 7d763a47..af77615e 100755
--- a/test/tooltest.py
+++ b/test/tooltest.py
@@ -110,9 +110,9 @@ cfg = {
 	'tmpdir':        'test/tmp10',
 	'tmpdir_num':    10,
 	'refdir':        'test/ref',
-	'txfile':        'FFB367[1.234].rawtx',
-	'addrfile':      '98831F3A[1,31-33,500-501,1010-1011].addrs',
-	'addrfile_chk':  '6FEF 6FB9 7B13 5D91',
+	'txfile':        'FFB367[1.234]{}.rawtx',
+	'addrfile':      '98831F3A[1,31-33,500-501,1010-1011]{}.addrs',
+	'addrfile_chk':  ('6FEF 6FB9 7B13 5D91','3C2C 8558 BB54 079E'),
 }
 
 opts_data = lambda: {
@@ -169,7 +169,7 @@ if opt.list_names:
 
 import binascii
 from mmgen.test import *
-from mmgen.tx import is_wif,is_btc_addr
+from mmgen.tx import is_wif,is_coin_addr
 
 msg_w = 35
 def test_msg(m):
@@ -329,7 +329,7 @@ class MMGenToolTestSuite(object):
 		for n,k in enumerate(['','compressed=1','segwit=1 compressed=1']):
 			wif,addr = self.run_cmd_out(name,kwargs=k,Return=True,fn_idx=n+1).split()
 			ok_or_die(wif,is_wif,'WIF key',skip_ok=True)
-			ok_or_die(addr,is_btc_addr,'Bitcoin address')
+			ok_or_die(addr,is_coin_addr,'Bitcoin address')
 	def Wif2addr(self,name,f1,f2,f3):
 		for n,f,k,m in ((1,f1,'',''),(2,f2,'','compressed'),(3,f3,'segwit=1','compressed')):
 			wif = read_from_file(f).split()[0]
@@ -356,7 +356,7 @@ class MMGenToolTestSuite(object):
 			self.run_cmd_chk(name,fi,fo,extra_msg=m)
 	def Privhex2pubhex(self,name,f1,f2,f3): # from Hex2wif
 		addr = read_from_file(f3).strip()
-		self.run_cmd_out(name,addr,kwargs='compressed=1',fn_idx=3)
+		self.run_cmd_out(name,addr,kwargs='compressed=1',fn_idx=3) # what about uncompressed?
 	def Pubhex2redeem_script(self,name,f1,f2,f3): # from above
 		addr = read_from_file(f3).strip()
 		self.run_cmd_out(name,addr,fn_idx=3)
@@ -406,8 +406,8 @@ class MMGenToolTestSuite(object):
 
 	# RPC
 	def Addrfile_chksum(self,name):
-		fn = os.path.join(cfg['refdir'],cfg['addrfile'])
-		self.run_cmd_out(name,fn,literal=True,chkdata=cfg['addrfile_chk'])
+		fn = os.path.join(cfg['refdir'],cfg['addrfile'].format(('','.testnet')[g.testnet]))
+		self.run_cmd_out(name,fn,literal=True,chkdata=cfg['addrfile_chk'][g.testnet])
 	def Getbalance(self,name):
 		self.run_cmd_out(name,literal=True)
 	def Listaddresses(self,name):
@@ -415,7 +415,7 @@ class MMGenToolTestSuite(object):
 	def Twview(self,name):
 		self.run_cmd_out(name,literal=True)
 	def Txview(self,name):
-		fn = os.path.join(cfg['refdir'],cfg['txfile'])
+		fn = os.path.join(cfg['refdir'],cfg['txfile'].format(('','.testnet')[g.testnet]))
 		self.run_cmd_out(name,fn,literal=True)
 
 # main()