diff --git a/.gitignore b/.gitignore
index 9c759a8..85c7f15 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,5 @@
 */tmp
 */*/tmp
 /comparator/sky130_fd_pr
+/old-comparator/sky130_fd_pr
 *.ext
\ No newline at end of file
diff --git a/gds/user_analog_project_wrapper.gds b/gds/user_analog_project_wrapper.gds
index 6c15cc7..b737cf2 100644
--- a/gds/user_analog_project_wrapper.gds
+++ b/gds/user_analog_project_wrapper.gds
Binary files differ
diff --git a/mag/user_analog_project_wrapper.mag b/mag/user_analog_project_wrapper.mag
index 053243c..d533d7a 100644
--- a/mag/user_analog_project_wrapper.mag
+++ b/mag/user_analog_project_wrapper.mag
@@ -1,11 +1,6 @@
 magic
 tech sky130A
-timestamp 1620244087
-<< checkpaint >>
-rect -680 351370 292680 352680
-rect -680 630 630 351370
-rect 291370 630 292680 351370
-rect -680 -680 292680 630
+timestamp 1632865452
 << metal2 >>
 rect 262 -400 318 240
 rect 853 -400 909 240
@@ -691,6 +686,10 @@
 rect -50 0 0 352000
 rect 292000 0 292050 352000
 rect -50 -50 292050 0
+use comparator  comparator_0 /mnt/c/Users/Harry/magic-practice/caravel_user_project_analog/comparator
+timestamp 1632865024
+transform 1 0 2220 0 1 49050
+box -220 -50 2800 1700
 << labels >>
 flabel metal3 s 291760 134615 292400 134671 0 FreeSans 560 0 0 0 gpio_analog[0]
 port 0 nsew signal bidirectional
@@ -2049,5 +2048,5 @@
 flabel metal2 s 3217 -400 3273 240 0 FreeSans 560 90 0 0 wbs_we_i
 port 677 nsew signal input
 << properties >>
-string FIXED_BBOX 0 0 292000 352000
+string FIXED_BBOX 0 0 584000 704000
 << end >>
diff --git a/old-comparator/.magicrc b/old-comparator/.magicrc
new file mode 100644
index 0000000..cb421a8
--- /dev/null
+++ b/old-comparator/.magicrc
@@ -0,0 +1,74 @@
+puts stdout "Sourcing design .magicrc for technology sky130A ..."
+
+# scale to one
+set scalefac [tech lambda]
+if {[lindex $scalefac 1] < 2} {
+    scalegrid 1 1
+}
+
+# drc off
+drc euclidean on
+
+# Allow override of PDK path from environment variable PDKPATH
+if {[catch {set PDKPATH $env(PDKPATH)}]} {
+    set PDKPATH "~/open_sky130/sky130A"
+}
+
+# loading technology
+tech load $PDKPATH/libs.tech/magic/sky130A.tech
+
+# load device generator
+source $PDKPATH/libs.tech/magic/sky130A.tcl
+
+# load bind keys (optional)
+# source $PDKPATH/libs.tech/magic/sky130A-BindKeys
+
+# set sky130 standard power, ground, and substrate names
+set VDD VPWR
+set GND VGND
+set SUB VSUBS
+
+# Allow override of type of magic library views used, "mag" or "maglef",
+# from environment variable MAGTYPE
+
+if {[catch {set MAGTYPE $env(MAGTYPE)}]} {
+   set MAGTYPE maglef
+}
+
+# add path to reference cells
+if {[file isdir ${PDKPATH}/libs.ref/${MAGTYPE}]} {
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_fd_pr
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_fd_io
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_fd_sc_hd
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_fd_sc_hdll
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_fd_sc_hs
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_fd_sc_hvl
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_fd_sc_lp
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_fd_sc_ls
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_fd_sc_ms
+    addpath ${PDKPATH}/libs.ref/${MAGTYPE}/sky130_osu_sc
+} else {
+    addpath ${PDKPATH}/libs.ref/sky130_fd_pr/${MAGTYPE}
+    addpath ${PDKPATH}/libs.ref/sky130_fd_io/${MAGTYPE}
+    addpath ${PDKPATH}/libs.ref/sky130_fd_sc_hd/${MAGTYPE}
+    addpath ${PDKPATH}/libs.ref/sky130_fd_sc_hdll/${MAGTYPE}
+    addpath ${PDKPATH}/libs.ref/sky130_fd_sc_hs/${MAGTYPE}
+    addpath ${PDKPATH}/libs.ref/sky130_fd_sc_hvl/${MAGTYPE}
+    addpath ${PDKPATH}/libs.ref/sky130_fd_sc_lp/${MAGTYPE}
+    addpath ${PDKPATH}/libs.ref/sky130_fd_sc_ls/${MAGTYPE}
+    addpath ${PDKPATH}/libs.ref/sky130_fd_sc_ms/${MAGTYPE}
+    addpath ${PDKPATH}/libs.ref/sky130_osu_sc/${MAGTYPE}
+}
+
+# add path to GDS cells
+
+# add path to IP from catalog.  This procedure defined in the PDK script.
+catch {magic::query_mylib_ip}
+# add path to local IP from user design space.  Defined in the PDK script.
+catch {magic::query_my_projects}
+
+# set units for grid
+snap on
+
+ext2spice scale off
+ext2spice ngspice
\ No newline at end of file
diff --git a/comparator/bsim4v5.out b/old-comparator/bsim4v5.out
similarity index 100%
rename from comparator/bsim4v5.out
rename to old-comparator/bsim4v5.out
diff --git a/comparator/comparator-decision.spice b/old-comparator/comparator-decision.spice
similarity index 100%
rename from comparator/comparator-decision.spice
rename to old-comparator/comparator-decision.spice
diff --git a/comparator/comparator-diffamp.spice b/old-comparator/comparator-diffamp.spice
similarity index 100%
rename from comparator/comparator-diffamp.spice
rename to old-comparator/comparator-diffamp.spice
diff --git a/comparator/comparator.mag b/old-comparator/comparator-large.mag
similarity index 100%
rename from comparator/comparator.mag
rename to old-comparator/comparator-large.mag
diff --git a/comparator/comparator.spice b/old-comparator/comparator-large.spice
similarity index 100%
rename from comparator/comparator.spice
rename to old-comparator/comparator-large.spice
diff --git a/comparator/comparator-preamp-selfbias.spice b/old-comparator/comparator-preamp-selfbias.spice
similarity index 100%
rename from comparator/comparator-preamp-selfbias.spice
rename to old-comparator/comparator-preamp-selfbias.spice
diff --git a/comparator/comparator-preamp.spice b/old-comparator/comparator-preamp.spice
similarity index 100%
rename from comparator/comparator-preamp.spice
rename to old-comparator/comparator-preamp.spice
diff --git a/comparator/comparator-whole.spice b/old-comparator/comparator-whole.spice
similarity index 100%
rename from comparator/comparator-whole.spice
rename to old-comparator/comparator-whole.spice
diff --git a/comparator/decision.mag b/old-comparator/decision.mag
similarity index 100%
rename from comparator/decision.mag
rename to old-comparator/decision.mag
diff --git a/comparator/decision.spice b/old-comparator/decision.spice
similarity index 100%
rename from comparator/decision.spice
rename to old-comparator/decision.spice
diff --git a/comparator/diffamp.mag b/old-comparator/diffamp.mag
similarity index 100%
rename from comparator/diffamp.mag
rename to old-comparator/diffamp.mag
diff --git a/comparator/diffamp.spice b/old-comparator/diffamp.spice
similarity index 100%
rename from comparator/diffamp.spice
rename to old-comparator/diffamp.spice
diff --git a/comparator/preamp.mag b/old-comparator/preamp.mag
similarity index 100%
rename from comparator/preamp.mag
rename to old-comparator/preamp.mag
diff --git a/comparator/preamp.spice b/old-comparator/preamp.spice
similarity index 100%
rename from comparator/preamp.spice
rename to old-comparator/preamp.spice
diff --git a/comparator/simulation.spice b/old-comparator/simulation.spice
similarity index 100%
rename from comparator/simulation.spice
rename to old-comparator/simulation.spice
diff --git a/comparator/sky130_fd_pr__nfet_01v8_T49HPK.mag b/old-comparator/sky130_fd_pr__nfet_01v8_T49HPK.mag
similarity index 100%
rename from comparator/sky130_fd_pr__nfet_01v8_T49HPK.mag
rename to old-comparator/sky130_fd_pr__nfet_01v8_T49HPK.mag
diff --git a/comparator/sky130_fd_pr__nfet_01v8_YZDSNP.mag b/old-comparator/sky130_fd_pr__nfet_01v8_YZDSNP.mag
similarity index 100%
rename from comparator/sky130_fd_pr__nfet_01v8_YZDSNP.mag
rename to old-comparator/sky130_fd_pr__nfet_01v8_YZDSNP.mag
diff --git a/comparator/sky130_fd_pr__nfet_03v3_nvt_BKHJCF.mag b/old-comparator/sky130_fd_pr__nfet_03v3_nvt_BKHJCF.mag
similarity index 100%
rename from comparator/sky130_fd_pr__nfet_03v3_nvt_BKHJCF.mag
rename to old-comparator/sky130_fd_pr__nfet_03v3_nvt_BKHJCF.mag
diff --git a/comparator/sky130_fd_pr__nfet_03v3_nvt_DWHJCV.mag b/old-comparator/sky130_fd_pr__nfet_03v3_nvt_DWHJCV.mag
similarity index 100%
rename from comparator/sky130_fd_pr__nfet_03v3_nvt_DWHJCV.mag
rename to old-comparator/sky130_fd_pr__nfet_03v3_nvt_DWHJCV.mag
diff --git a/comparator/sky130_fd_pr__nfet_03v3_nvt_NAHJCF.mag b/old-comparator/sky130_fd_pr__nfet_03v3_nvt_NAHJCF.mag
similarity index 100%
rename from comparator/sky130_fd_pr__nfet_03v3_nvt_NAHJCF.mag
rename to old-comparator/sky130_fd_pr__nfet_03v3_nvt_NAHJCF.mag
diff --git a/comparator/sky130_fd_pr__nfet_03v3_nvt_RPCQRP.mag b/old-comparator/sky130_fd_pr__nfet_03v3_nvt_RPCQRP.mag
similarity index 100%
rename from comparator/sky130_fd_pr__nfet_03v3_nvt_RPCQRP.mag
rename to old-comparator/sky130_fd_pr__nfet_03v3_nvt_RPCQRP.mag
diff --git a/comparator/sky130_fd_pr__nfet_03v3_nvt_ZJHJCF.mag b/old-comparator/sky130_fd_pr__nfet_03v3_nvt_ZJHJCF.mag
similarity index 100%
rename from comparator/sky130_fd_pr__nfet_03v3_nvt_ZJHJCF.mag
rename to old-comparator/sky130_fd_pr__nfet_03v3_nvt_ZJHJCF.mag
diff --git a/comparator/sky130_fd_pr__pfet_01v8_X4T9AL.mag b/old-comparator/sky130_fd_pr__pfet_01v8_X4T9AL.mag
similarity index 100%
rename from comparator/sky130_fd_pr__pfet_01v8_X4T9AL.mag
rename to old-comparator/sky130_fd_pr__pfet_01v8_X4T9AL.mag
diff --git a/comparator/sky130_fd_pr__pfet_01v8_XAY5ZQ.mag b/old-comparator/sky130_fd_pr__pfet_01v8_XAY5ZQ.mag
similarity index 100%
rename from comparator/sky130_fd_pr__pfet_01v8_XAY5ZQ.mag
rename to old-comparator/sky130_fd_pr__pfet_01v8_XAY5ZQ.mag
diff --git a/comparator/sky130_fd_pr__pfet_01v8_XWX67S.mag b/old-comparator/sky130_fd_pr__pfet_01v8_XWX67S.mag
similarity index 100%
rename from comparator/sky130_fd_pr__pfet_01v8_XWX67S.mag
rename to old-comparator/sky130_fd_pr__pfet_01v8_XWX67S.mag
diff --git a/comparator/sky130_fd_pr__pfet_g5v0d10v5_7EB329.mag b/old-comparator/sky130_fd_pr__pfet_g5v0d10v5_7EB329.mag
similarity index 100%
rename from comparator/sky130_fd_pr__pfet_g5v0d10v5_7EB329.mag
rename to old-comparator/sky130_fd_pr__pfet_g5v0d10v5_7EB329.mag
diff --git a/comparator/sky130_fd_pr__pfet_g5v0d10v5_7EFQZ5.mag b/old-comparator/sky130_fd_pr__pfet_g5v0d10v5_7EFQZ5.mag
similarity index 100%
rename from comparator/sky130_fd_pr__pfet_g5v0d10v5_7EFQZ5.mag
rename to old-comparator/sky130_fd_pr__pfet_g5v0d10v5_7EFQZ5.mag
diff --git a/comparator/sky130_fd_pr__pfet_g5v0d10v5_CABTE7.mag b/old-comparator/sky130_fd_pr__pfet_g5v0d10v5_CABTE7.mag
similarity index 100%
rename from comparator/sky130_fd_pr__pfet_g5v0d10v5_CABTE7.mag
rename to old-comparator/sky130_fd_pr__pfet_g5v0d10v5_CABTE7.mag
diff --git a/comparator/tristate-inverter.spice b/old-comparator/tristate-inverter.spice
similarity index 100%
rename from comparator/tristate-inverter.spice
rename to old-comparator/tristate-inverter.spice