diff --git a/iocBoot/Makefile b/iocBoot/Makefile
new file mode 100644
index 0000000..91e47d0
--- /dev/null
+++ b/iocBoot/Makefile
@@ -0,0 +1,6 @@
+TOP = ..
+include $(TOP)/configure/CONFIG
+DIRS += $(wildcard *ioc*)
+DIRS += $(wildcard as*)
+include $(CONFIG)/RULES_DIRS
+
diff --git a/iocBoot/README b/iocBoot/README
new file mode 100644
index 0000000..9dd5d00
--- /dev/null
+++ b/iocBoot/README
@@ -0,0 +1,18 @@
+Demo IOCs
+
+ioccircle and ioccircle together demonstrate PVA groups and links.
+ioccircle maintains a "phase" counter which counts from 0 to 359
+then rolls over.
+
+From this phase are calculated an X and Y which are points on a circule with radius 1.
+
+A group PVA PV is defined which includes both and X and Y.
+
+ioccircle2 contains two calc records which subscribe to the X and Y
+from ioccircle and multiply each by 2.
+
+A second group PVA PV is defined including the multipled X and Y.
+
+Due to the atomicity of a group PV it is certain that pairs of
+X and Y will not be mixed.  In this example, the magnitude
+sqrt(X*X+Y*Y) will never change by more than floating point epsilon.
diff --git a/iocBoot/ioccircle/Makefile b/iocBoot/ioccircle/Makefile
new file mode 100644
index 0000000..89d66d0
--- /dev/null
+++ b/iocBoot/ioccircle/Makefile
@@ -0,0 +1,5 @@
+TOP = ../..
+include $(TOP)/configure/CONFIG
+ARCH = linux-x86_64-debug
+TARGETS = envPaths
+include $(TOP)/configure/RULES.ioc
diff --git a/iocBoot/ioccircle/circle.db b/iocBoot/ioccircle/circle.db
new file mode 100644
index 0000000..aa04ac3
--- /dev/null
+++ b/iocBoot/ioccircle/circle.db
@@ -0,0 +1,53 @@
+record(ao, "circle:step") {
+  field(VAL , "1.0")
+  field(DRVL, "0.0")
+  field(DRVH, "359")
+  field(PINI, "YES")
+#  field(TPRO, "1")
+}
+
+record(ao, "circle:period") {
+  field(VAL , "1.0")
+  field(PINI, "YES")
+  field(OUT , "circle:y.ODLY NPP")
+#  field(TPRO, "1")
+}
+
+record(calc, "circle:angle") {
+  field(PINI, "RUNNING")
+#  field(SCAN, "2 second")
+  field(INPA, "circle:angle NPP")
+  field(INPB, "circle:step NPP")
+  field(INPD, "360")
+  field(CALC, "C:=A+B;(C>D)?C-D:C")
+  field(FLNK, "circle:x")
+  field(PREC, "3")
+#  field(TPRO, "1")
+  info(pdbGroup, "circle|angle=VAL")
+}
+
+record(calc, "circle:x") {
+  field(INPA, "circle:angle NPP")
+  field(CALC, "cos(A*PI/180)")
+  field(TSEL, "circle:angle.TIME")
+  field(FLNK, "circle:y")
+  field(PREC, "3")
+  info(pdbGroup, "circle|x=VAL")
+}
+
+record(calc, "circle:y") {
+  field(INPA, "circle:angle NPP")
+  field(CALC, "sin(A*PI/180)")
+  field(TSEL, "circle:angle.TIME")
+  field(PREC, "3")
+  field(FLNK, "circle:tick")
+  info(pdbGroup, "circle|y=VAL")
+  info(pdbTrigger,"circle|y>*")
+
+}
+
+record(calcout, "circle:tick") {
+  field(ODLY, "1.0")
+  field(OUT , "circle:angle.PROC CA") # loop
+#  field(TPRO, "1")
+}
diff --git a/iocBoot/ioccircle/st.cmd b/iocBoot/ioccircle/st.cmd
new file mode 100755
index 0000000..0a096fc
--- /dev/null
+++ b/iocBoot/ioccircle/st.cmd
@@ -0,0 +1,5 @@
+#!../../bin/linux-x86_64-debug/softIocPVA
+
+dbLoadRecords("circle.db","")
+
+iocInit()
diff --git a/iocBoot/ioccircle2/Makefile b/iocBoot/ioccircle2/Makefile
new file mode 100644
index 0000000..89d66d0
--- /dev/null
+++ b/iocBoot/ioccircle2/Makefile
@@ -0,0 +1,5 @@
+TOP = ../..
+include $(TOP)/configure/CONFIG
+ARCH = linux-x86_64-debug
+TARGETS = envPaths
+include $(TOP)/configure/RULES.ioc
diff --git a/iocBoot/ioccircle2/circle2.db b/iocBoot/ioccircle2/circle2.db
new file mode 100644
index 0000000..67718bd
--- /dev/null
+++ b/iocBoot/ioccircle2/circle2.db
@@ -0,0 +1,27 @@
+record(calc, "circle2:x") {
+  field(INPA, "pva://circle.x CP")
+  field(CALC, "2*A")
+  field(FLNK, "circle2:y")
+  info(pdbGroup, "circle2|x=VAL")
+#  field(TPRO, "1")
+}
+
+record(calc, "circle2:y") {
+  field(INPA, "pva://circle.y")
+  field(CALC, "2*A")
+  field(TSEL, "circle2:x.TIME")
+  field(FLNK, "circle2:mag")
+  info(pdbGroup, "circle2|y=VAL")
+#  field(TPRO, "1")
+}
+
+record(calc, "circle2:mag") {
+  field(INPA, "circle2:x NPP")
+  field(INPB, "circle2:y NPP")
+  field(CALC, "SQRT(A*A+B*B)")
+  field(MDEL, "-1")
+  field(TSEL, "circle2:x.TIME")
+  info(pdbGroup, "circle2|mag=VAL")
+  info(pdbTrigger,"circle2|mag>*")
+#  field(TPRO, "1")
+}
diff --git a/iocBoot/ioccircle2/st.cmd b/iocBoot/ioccircle2/st.cmd
new file mode 100755
index 0000000..ea3ad06
--- /dev/null
+++ b/iocBoot/ioccircle2/st.cmd
@@ -0,0 +1,5 @@
+#!../../bin/linux-x86_64-debug/softIocPVA
+
+dbLoadRecords("circle2.db","")
+
+iocInit()