diff --git a/client/noise_test.py b/client/noise_test.py
index 408c369..9a92feb 100644
--- a/client/noise_test.py
+++ b/client/noise_test.py
@@ -39,8 +39,10 @@ def sign_extend(value, bits):
 ###################
 
 # Start a SSH connection to the server.
+print('connecting')
 client = SSHClient('192.168.1.50', user='root', pkey='~/.ssh/upsilon_key')
 # Upload the script.
+print('connected')
 client.scp_send('../linux/noise_test.py', '/root/noise_test.py')
 # Run the script.
 out = client.run_command('micropython noise_test.py')
diff --git a/doc/docker.md b/doc/docker.md
index d6860aa..c277336 100644
--- a/doc/docker.md
+++ b/doc/docker.md
@@ -7,12 +7,17 @@ beginner.
 
 # Setup steps
 
-Change directory to `build`.
+Do all of the following in the `build` folder.
 
 ## Installing OpenFPGALoader
 
 Install [openFPGALoader][1]. If this program is not in your repositories,
-run `make openFPGALoader` to fetch and install the program.
+run `make openFPGALoader` to fetch and build the program. This will install
+openFPGALoader locally.
+
+Even if you install openFPGALoader locally, there are some files (udev rules)
+that must be installed with administrative privleges. Check the documentation
+for openFPGALoader.
 
 [1]: https://trabucayre.github.io/openFPGALoader/index.html
 
diff --git a/doc/fixedpoint.py b/doc/fixedpoint.py
deleted file mode 100644
index aa6a93c..0000000
--- a/doc/fixedpoint.py
+++ /dev/null
@@ -1,70 +0,0 @@
-# Copyright (C) Peter McGoron
-#
-# This file is a part of Upsilon, a free and open source software project.
-# For license terms, refer to the files in `doc/copying` in the Upsilon 
-# source distribution.
-
-# Functions for converting to and from fixed point in Python.
-from math import log10, floor
-from decimal import *
-
-def string_to_fixed_point(s, fracnum):
-	l = s.split('.')
-	if len(l) == 1:
-		return int(s) << fracnum
-	elif len(l) != 2:
-		return None
-
-	dec = 10
-	frac = 0
-
-	frac_decimal = Decimal(f'0.{l[1]}')
-	# get the smallest power of ten higher then frac_decimal
-	frac = 0
-
-	# Example:
-	# 0.4567 = 0.abcdefgh...
-	# where abcdefgh are binary digits.
-	# multiply both sides by two:
-	# 0.9134 = a.bcdefgh ...
-	# therefore a = 0. Then remove the most significant digit.
-	# Then multiply by 2 again. Then
-	# 1.8268 = b.cdefgh ...
-	# therefore b = 1. Then take 8268, and so on.
-	for i in range(0,fracnum):
-		frac_decimal = frac_decimal * 2	
-		div = floor(frac_decimal)
-
-		frac = div | (frac << 1)
-		frac_decimal = frac_decimal - div
-
-	whole = int(l[0])
-	if whole < 0:
-		return -((-whole) << fracnum | frac)
-	else:
-		return whole << fracnum | frac
-
-def fixed_point_to_string(fxp, fracnum):
-	whole = str(fxp >> fracnum)
-	mask = (1 << fracnum) - 1
-	fracbit = fxp & mask
-	n = 1
-	frac = ""
-
-	if fracbit == 0:
-		return whole
-
-	# The same method can be applied backwards.
-	#    0.1110101 = 0.abcdefgh ...
-	# where abcdefgh... are decimal digits. Then multiply by 10 to
-	# get
-	# 1001.0010010 = a.bcdefgh ...
-	# therefore a = 0b1001 = 9. Then use a bitmask to get
-	#    0.0010010 = 0.bcdefgh ...
-	# etc.
-
-	for i in range(0, fracnum):
-		fracbit = fracbit * 10
-		frac = frac + str(fracbit >> fracnum)
-		fracbit = fracbit & mask
-	return whole + "." + frac
diff --git a/gateware/rtl/control_loop/control_loop_math.v.m4 b/gateware/rtl/control_loop/control_loop_math.v.m4
index 7a93c39..6e76e06 100644
--- a/gateware/rtl/control_loop/control_loop_math.v.m4
+++ b/gateware/rtl/control_loop/control_loop_math.v.m4
@@ -39,15 +39,15 @@ m4_define(M4_CONSTS_WID, (CONSTS_WHOLE + CONSTS_FRAC))
 	parameter [M4_CONSTS_WID-1:0] SEC_PER_CYCLE = 'b10101011110011000,
 	/* To calculate this value:
 	 * Load doc/fixedpoint.py
-	 * run bin(string_to_fixed_point(str((ADC_RANGE/2**ADC_WID)/(DAC_RANGE/2**DAC_WID)), CONSTS_FRAC))
-	 * This value is the value to put below.
-	 * This value uses ADC_RANGE=20.48, DAC_RANGE=30
+	 * run bin(string_to_fixed_point(str((DAC_RANGE/2**DAC_WID)/(ADC_RANGE/2**ADC_WID)), CONSTS_FRAC))
+	 * This value uses ADC_RANGE=20.48, DAC_RANGE=32
 	 * The ranges are the range of values REPRESENTABLE by the ADC and DAC,
 	 * not the values you expect to get!
 	 */
 	parameter [M4_CONSTS_WID-1:0] ADC_TO_DAC =
 /* 64'b0100000110001001001101110100101111000110101, */
-64'b0101110111000000000000000000000000000000000,
+/* 64'b0101110111000000000000000000000000000000000, */
+   64'b0110010000000000000000000000000000000000000,
 	parameter CYCLE_COUNT_WID = 18,
 	parameter DAC_WID = 20
 m4_define(M4_E_WID, (DAC_WID + 1))
diff --git a/gateware/rtl/control_loop/control_loop_math_sim.cpp b/gateware/rtl/control_loop/control_loop_math_sim.cpp
index d39b1e7..2f8732e 100644
--- a/gateware/rtl/control_loop/control_loop_math_sim.cpp
+++ b/gateware/rtl/control_loop/control_loop_math_sim.cpp
@@ -37,7 +37,7 @@ static void init(int argc, char **argv) {
 using V = int64_t;
 
 constexpr V per100 = 0b010101011110011000;
-constexpr V adc_to_dac = 0b0101110111000000000000000000000000000000000;
+constexpr V adc_to_dac = 0b0110010000000000000000000000000000000000000;
 
 static void calculate() {
 	/* Multiplication adds an extra CONSTS_FRAC bits to the end,
diff --git a/gateware/rtl/spi/spi_switch.v b/gateware/rtl/spi/spi_switch.v
index ca9dbed..0ddf361 100644
--- a/gateware/rtl/spi/spi_switch.v
+++ b/gateware/rtl/spi/spi_switch.v
@@ -27,7 +27,9 @@ module spi_switch #(
 );
 
 /* Avoid using for loops, they might not synthesize correctly.
-   Do things the old, dumb way instead.
+ * Do things the old, dumb way instead.
+ *
+ * TODO: Instead of bit vector, use regular numbers
  */
 
 `define do_select(n)            \