diff --git a/artiq/gateware/nist_qc2.py b/artiq/gateware/nist_qc2.py
index 6bab29bcf..8e9f0970a 100644
--- a/artiq/gateware/nist_qc2.py
+++ b/artiq/gateware/nist_qc2.py
@@ -9,7 +9,7 @@ __all__ = ["fmc_adapter_io"]
 ttl_pins = [
     "LA00_CC_P", "LA02_P", "LA00_CC_N", "LA02_N", "LA01_CC_P", "LA01_CC_N", "LA06_P", "LA06_N",
     "LA05_P", "LA05_N", "LA10_P", "LA09_P", "LA10_N", "LA09_N", "LA13_P", "LA14_P",
-    "LA27_P", "LA26_P", "LA27_N", "LA26_N"
+    "LA13_N", "LA14_N", "LA17_CC_P", "LA17_CC_N"
 ]
 
 
@@ -53,19 +53,19 @@ def get_fmc_adapter_io():
             ("clkout", next(clkout), FPins("FMC:CLK1_M2C_P"),
                 IOStandard("LVTTL")),
 
-            ("spi", next(spi),
-                Subsignal("clk", FPins("FMC:LA13_N")),
-                Subsignal("mosi", FPins("FMC:LA14_N")),
-                Subsignal("miso", FPins("FMC:LA17_CC_P")),
-                Subsignal("cs_n", FPins("FMC:LA17_CC_N")),
-                IOStandard("LVTTL")),
-
             ("spi", next(spi),
                 Subsignal("clk", FPins("FMC:LA18_CC_P")),
                 Subsignal("mosi", FPins("FMC:LA18_CC_N")),
                 Subsignal("miso", FPins("FMC:LA23_P")),
                 Subsignal("cs_n", FPins("FMC:LA23_N")),
                 IOStandard("LVTTL")),
+
+            ("spi", next(spi),
+                Subsignal("clk", FPins("FMC:LA27_P")),
+                Subsignal("mosi", FPins("FMC:LA26_P")),
+                Subsignal("miso", FPins("FMC:LA27_N")),
+                Subsignal("cs_n", FPins("FMC:LA26_N")),
+                IOStandard("LVTTL")),
         ]
     return r
 
diff --git a/artiq/gateware/targets/kc705.py b/artiq/gateware/targets/kc705.py
index 2692c8ea5..c74a72cdc 100755
--- a/artiq/gateware/targets/kc705.py
+++ b/artiq/gateware/targets/kc705.py
@@ -310,27 +310,22 @@ class NIST_QC2(_NIST_Ions):
 
         rtio_channels = []
         clock_generators = []
-        for backplane_offset in 0, 20:
-            # TTL0-15, 20-35 are In+Out capable
-            for i in range(16):
-                phy = ttl_serdes_7series.Inout_8X(
-                    platform.request("ttl", backplane_offset+i))
-                self.submodules += phy
-                rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=512))
-            # TTL16-19, 36-39 are output only
-            for i in range(16, 20):
-                phy = ttl_serdes_7series.Output_8X(
-                    platform.request("ttl", backplane_offset+i))
-                self.submodules += phy
-                rtio_channels.append(rtio.Channel.from_phy(phy))
+
+        # All TTL channels are In+Out capable
+        for i in range(40):
+            phy = ttl_serdes_7series.Inout_8X(
+                platform.request("ttl", i))
+            self.submodules += phy
+            rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=512))
         
-        # CLK0, CLK1 are for the clock generators, on backplane SMP connectors
-        for backplane_offset in range(2):        
+        # CLK0, CLK1 are for clock generators, on backplane SMP connectors
+        for i in range(2):        
             phy = ttl_simple.ClockGen(
-                platform.request("clkout", backplane_offset))
+                platform.request("clkout", i))
             self.submodules += phy
             clock_generators.append(rtio.Channel.from_phy(phy)) 
 
+        # user SMA on KC705 board
         phy = ttl_serdes_7series.Inout_8X(platform.request("user_sma_gpio_n"))
         self.submodules += phy
         rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=512))
@@ -339,6 +334,7 @@ class NIST_QC2(_NIST_Ions):
         self.submodules += phy
         rtio_channels.append(rtio.Channel.from_phy(phy))
 
+        # AMS101 DAC on KC705 XADC header - optional
         ams101_dac = self.platform.request("ams101_dac", 0)
         phy = ttl_simple.Output(ams101_dac.ldac)
         self.submodules += phy
diff --git a/doc/manual/core_device.rst b/doc/manual/core_device.rst
index 2cbd49701..5d3800e09 100644
--- a/doc/manual/core_device.rst
+++ b/doc/manual/core_device.rst
@@ -104,9 +104,7 @@ With the QC2 hardware, the TTL lines are mapped as follows:
 +--------------------+-----------------------+--------------+
 | RTIO channel       | TTL line              | Capability   |
 +====================+=======================+==============+
-| 0-15, 20-35        | TTL0-15, TTL20-35     | Input+Output |
-+--------------------+-----------------------+--------------+
-| 16-19, 36-39       | TTL16-19, TTL36-39    | Output       |
+| 0-39               | TTL0-39               | Input+Output |
 +--------------------+-----------------------+--------------+
 | 40                 | SMA_GPIO_N            | Input+Output |
 +--------------------+-----------------------+--------------+