diff --git a/minitests/iob/DRIVE.tcl b/minitests/iob/DRIVE.tcl
new file mode 100644
index 00000000..171315b2
--- /dev/null
+++ b/minitests/iob/DRIVE.tcl
@@ -0,0 +1,9 @@
+source "$::env(SRC_DIR)/template.tcl"
+
+# set vals "0 4 8 12 16 24"
+# ERROR: [Common 17-69] Command failed: Illegal DRIVE_STRENGTH value '0' for standard 'LVCMOS33'.
+# Legal values: 4, 8, 12, 16
+set prop DRIVE
+set port [get_ports do]
+source "$::env(SRC_DIR)/sweep.tcl"
+
diff --git a/minitests/iob/IOSTANDARD.tcl b/minitests/iob/IOSTANDARD.tcl
new file mode 100644
index 00000000..09871672
--- /dev/null
+++ b/minitests/iob/IOSTANDARD.tcl
@@ -0,0 +1,6 @@
+source "$::env(SRC_DIR)/template.tcl"
+
+set prop IOSTANDARD
+set port [get_ports do]
+source "$::env(SRC_DIR)/sweep.tcl"
+
diff --git a/minitests/iob/Makefile b/minitests/iob/Makefile
index d074989b..a0cd12fa 100644
--- a/minitests/iob/Makefile
+++ b/minitests/iob/Makefile
@@ -1,4 +1,9 @@
-all:  build/env build/roi_roi_io.diff
+all:  build/env build/roi_roi_io.diff \
+    build/PULLTYPE/run.ok \
+    build/SLEW/run.ok \
+    build/DRIVE/run.ok \
+    build/IOSTANDARD/run.ok \
+    
 
 clean:
 	rm -rf build
@@ -10,4 +15,18 @@ build/env:
 build/roi_roi_io.diff:
 	$(MAKE) -f diff.mk OUT_DIFF=build/roi_io.diff PRJL=roi_io_a PRJR=roi_io_b
 
+build/PULLTYPE/run.ok:
+	PROJECT=PULLTYPE bash runme_tcl.sh
+	diff build/PULLTYPE/design_{PULLDOWN,KEEPER}.bits || true
+	diff build/PULLTYPE/design_{PULLDOWN,PULLUP}.bits || true
+	diff build/PULLTYPE/design_{PULLDOWN,NONE}.bits || true
+
+build/SLEW/run.ok:
+	PROJECT=SLEW bash runme_tcl.sh
+
+build/DRIVE/run.ok:
+	PROJECT=DRIVE bash runme_tcl.sh
+
+build/IOSTANDARD/run.ok:
+	PROJECT=IOSTANDARD bash runme_tcl.sh
 
diff --git a/minitests/iob/PULLTYPE.tcl b/minitests/iob/PULLTYPE.tcl
new file mode 100644
index 00000000..c227fe1e
--- /dev/null
+++ b/minitests/iob/PULLTYPE.tcl
@@ -0,0 +1,15 @@
+source "$::env(SRC_DIR)/template.tcl"
+
+set port [get_ports di]
+
+set_property PULLTYPE "" $port
+write_checkpoint -force design_NONE.dcp
+write_bitstream -force design_NONE.bit
+
+set vals "KEEPER PULLUP PULLDOWN"
+foreach {val} $vals {
+    set_property PULLTYPE $val $port
+    write_checkpoint -force design_$val.dcp
+    write_bitstream -force design_$val.bit
+}
+
diff --git a/minitests/iob/README.md b/minitests/iob/README.md
index e69de29b..736770a2 100644
--- a/minitests/iob/README.md
+++ b/minitests/iob/README.md
@@ -0,0 +1,39 @@
+# PULLTYPE
+
+PULLTYPE    28  29  30
+NONE                X
+KEEPER      X       X
+PULLDOWN
+PULLUP          X   X
+
+
+# DRIVE
+
+DRIVE       A00 A02 A08 A10 B09 B01
+0           FIXME
+4           X   X           X
+8               X   X           X
+12          X   X               X
+16          X           X   X
+24          FIXME
+
+
+# IOSTANDARD
+
+Effects bits, TBD exactly how
+Sample output:
+
+diff LVCMOS33.bits LVTTL.bits
+< bit_00020026_006_00
+> bit_00020026_006_08
+
+diff LVCMOS33.bits PCI33_3.bits
+< bit_00020026_006_02
+< bit_00020026_006_18
+< bit_00020026_006_22
+> bit_00020026_006_10
+> bit_00020026_006_16
+> bit_00020026_006_20
+> bit_00020027_006_11
+> bit_00020027_006_15
+
diff --git a/minitests/iob/SLEW.tcl b/minitests/iob/SLEW.tcl
new file mode 100644
index 00000000..ac97d92c
--- /dev/null
+++ b/minitests/iob/SLEW.tcl
@@ -0,0 +1,8 @@
+source "$::env(SRC_DIR)/template.tcl"
+
+# set vals "SLOW MEDIUM FAST"
+# ERROR: [Common 17-69] Command failed: Slew type 'MEDIUM' is not supported by I/O standard 'LVCMOS33'
+set prop SLEW
+set port [get_ports do]
+source "$::env(SRC_DIR)/sweep.tcl"
+
diff --git a/minitests/iob/diff_tcl.mk b/minitests/iob/diff_tcl.mk
new file mode 100644
index 00000000..5c40cf3a
--- /dev/null
+++ b/minitests/iob/diff_tcl.mk
@@ -0,0 +1,11 @@
+all: $(OUT_DIFF)
+
+$(OUT_DIFF): build/$(PRJL)/design.bits build/$(PRJR)/design.bits
+	diff build/$(PRJL)/design.bits build/$(PRJR)/design.bits >$(OUT_DIFF) || true
+
+build/$(PRJL)/design.bits:
+	PROJECT=$(PRJL) bash runme_tcl.sh
+
+build/$(PRJR)/design.bits:
+	PROJECT=$(PRJR) bash runme_tcl.sh
+
diff --git a/minitests/iob/runme_tcl.sh b/minitests/iob/runme_tcl.sh
new file mode 100644
index 00000000..143dfdbf
--- /dev/null
+++ b/minitests/iob/runme_tcl.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+set -ex
+
+: "${PROJECT:?Need to set PROJECT non-empty}"
+
+# Create build dir
+export SRC_DIR=$PWD
+BUILD_DIR=build/$PROJECT
+mkdir -p $BUILD_DIR
+cd $BUILD_DIR
+
+export TOP_V=$SRC_DIR/tcl.v
+
+vivado -mode batch -source $SRC_DIR/$PROJECT.tcl
+for x in design*.bit; do
+	${XRAY_BITREAD} -F $XRAY_ROI_FRAMES -o ${x}s -z -y $x
+done
+test -z "$(fgrep CRITICAL vivado.log)"
+touch run.ok
+
diff --git a/minitests/iob/sweep.tcl b/minitests/iob/sweep.tcl
new file mode 100644
index 00000000..208f2195
--- /dev/null
+++ b/minitests/iob/sweep.tcl
@@ -0,0 +1,22 @@
+# Sweep all values of $prop on given I/O $port
+# Write out bitstream for all legal values
+
+set vals [list_property_value $prop $port]
+foreach {val} $vals {
+    puts $val
+    # Not all listable properties are settable
+    # Its easiest to try setting and see if it sticks
+    set_property -quiet $prop $val $port
+    set got [get_property $prop $port]
+    if {"$got" != "$val"} {
+        puts "  Skipping: wanted $val, got $got"
+        continue
+    }
+    if {[catch {write_bitstream -force design_$val.bit} issue]} {
+        puts "WARNING failed to write: $issue"
+        continue
+    }
+    # Only write checkpoints for acceptable bitstreams    
+    write_checkpoint -force design_$val.dcp
+}
+
diff --git a/minitests/iob/tcl.v b/minitests/iob/tcl.v
new file mode 100644
index 00000000..6535c2d8
--- /dev/null
+++ b/minitests/iob/tcl.v
@@ -0,0 +1,39 @@
+module top(input clk, stb, di, output do);
+	localparam integer DIN_N = 256;
+	localparam integer DOUT_N = 256;
+
+	reg [DIN_N-1:0] din;
+	wire [DOUT_N-1:0] dout;
+
+	reg [DIN_N-1:0] din_shr;
+	reg [DOUT_N-1:0] dout_shr;
+
+	always @(posedge clk) begin
+		din_shr <= {din_shr, di};
+		dout_shr <= {dout_shr, din_shr[DIN_N-1]};
+		if (stb) begin
+			din <= din_shr;
+			dout_shr <= dout;
+		end
+	end
+
+	assign do = dout_shr[DOUT_N-1];
+
+    roi
+	    roi (
+		.clk(clk),
+		.din(din),
+		.dout(dout)
+	);
+endmodule
+
+module roi(input clk, input [255:0] din, output [255:0] dout);
+    assign dout = din;
+endmodule
+
+/*
+module top (input i, output o);
+	assign o = i;
+endmodule
+*/
+
diff --git a/minitests/iob/template.tcl b/minitests/iob/template.tcl
new file mode 100644
index 00000000..0c0dc873
--- /dev/null
+++ b/minitests/iob/template.tcl
@@ -0,0 +1,20 @@
+# Create a simple design with a few IOs
+
+create_project -force -part $::env(XRAY_PART) design design
+read_verilog $::env(TOP_V)
+synth_design -top top -flatten_hierarchy none
+
+set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_00) IOSTANDARD LVCMOS33" [get_ports clk]
+set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_01) IOSTANDARD LVCMOS33" [get_ports stb]
+set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_02) IOSTANDARD LVCMOS33" [get_ports di]
+set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_03) IOSTANDARD LVCMOS33" [get_ports do]
+
+set_property CFGBVS VCCO [current_design]
+set_property CONFIG_VOLTAGE 3.3 [current_design]
+set_property BITSTREAM.GENERAL.PERFRAMECRC YES [current_design]
+
+set_property CLOCK_DEDICATED_ROUTE FALSE [get_nets clk_IBUF]
+
+place_design
+route_design
+