README.ASIC: Add a section for Gridseed

Includes command line options/arguments and sample block to add to bfgminer.conf for persistence.

AUTHORS

@@ -73,6 +73,7 @@ Raulo <p987341@gmail.com>
 Red_Wolf_2 <redwolf@wolfnexus.net>
 Ricardo Iván Vieitez Parra <cop3504@memoryplate.com>
 Rusty Russell <rusty@rustcorp.com.au>
+slax0r <frcole@gmail.com>
 Teemu Suikki <zuikkis@gmail.com>
 Thorsten Gilling <tgilling@web.de>
 Tydus <Tydus@Tydus.org>

README.ASIC

@@ -257,6 +257,48 @@ If you have different devices using the bifury driver, see the section on
 Hex*Fury for applying workarounds per-device.
 
 
+GRIDSEED
+--------
+
+Gridseed units, at the present time, come in two versions: Blade - a 40 chip
+unit and Orb - a 5 chip unit. Orb units can be used to mine both SHA256d and
+scrypt based coins whereas the Blade is scrypt only, although BFGMiner only
+supports scrypt mode at this time.
+
+BFGMiner allows a miner to connect both types of units to a single miner
+instance and provides for granular control of the clock frequencies for each
+device and each chip on each device. The basic use of this feature is to use the
+--set option on from the command line:
+
+bfgminer --scrypt -S gridseed:all --set gridseed@<serial_number>:clock=825
+
+for multiple devices, add multiple --set arguments.
+
+Additionally, these can be added to the bfgminer.conf file for persistence like
+this:
+
+"set" : [
+        "gridseed@<serial_number>:clock=825",
+        "gridseed@<serial_number>:clock=850",
+        "gridseed@<serial_number>:clock=875"
+]
+
+To find the device serial number, start bfgminer and press <M> to manage
+devices, then <Page Down> or <down arrow> through the list of devices and take
+note of the device serial number in the device information shown.
+
+...
+Select processor to manage using up/down arrow keys
+ GSD 0a:       |  74.4/ 72.9/ 10.2kh/s | A:  1 R:0+0(none) HW:0/none
+  STM32 Virtual COM Port from STMicroelectronics
+Serial: 6D85278F5650
+Clock speed: 875
+...
+
+So for example, an entry would look like this:
+        gridseed@6D85278F5650:clock=875
+
+
 ---
 
 This code is provided entirely free of charge by the programmer in his spare