diff --git a/sky130/custom/scripts/run_drc.py b/sky130/custom/scripts/run_drc.py
index d1c3761..0513066 100755
--- a/sky130/custom/scripts/run_drc.py
+++ b/sky130/custom/scripts/run_drc.py
@@ -1,42 +1,18 @@
 #!/bin/env python3
 #-------------------------------------------------------------------------
-# s8_gen_sealring.py ---  a seal ring generator for SkyWater s8 using magic.
-#
-# Because the seal ring contains many layers that do not appear in standard
-# layout editing, they are all specially implemented in the s8seal_ring.tech
-# file in this directory.
-#
-# An example seal ring was generated by SkyWater and imported using magic's
-# gdsquery.sh script.  It was then hand-edited to contain only the bottom
-# quarter.  Then it was saved in .mag databases.
-#
-# The generator script s8_gen_sealring.py calls magic using the s8seal_ring.tech
-# file, and automatically modifies the geometry to stretch to the half width
-# and height of the specified dimensions.  Then the lower-left cells are
-# copied and folded over the centerline to make the complete seal ring.
-# The seal ring is then written out in GDS format.  Then a simplified magic
-# view is generated in the usual user-facing s8 technology file, with the
-# GDS_FILE property pointing to the seal ring GDS.  This layout and GDS can
-# then be imported into a layout.
+# run_drc.py ---  A script to run magic in batch mode and apply full DRC
+# checks on a layout.  This inclues full DRC, antenna rule checks, and
+# density checks.
 #
 # Usage:
 #
-#   s8_gen_sealring.py width height target_dir [-force] [-outer] [-keep]
-#
-# Where:
-#   width = the full-chip layout width
-#   height = the full-chip layout height
-#   target_dir = location of the full-chip layout
-#
-#   -force = overwrite any existing files at the target
-#   -outer = width and height are the seal ring outer edge, not the chip area
-#   -keep = keep local working directory of results
+#   run_drc.py <layout_name>
 #
 # Results:
-#   Files advSeal_6um_gen.mag and advSeal_6um_gen.gds are generated and placed in
-#   target_dir.  advSeal_6um_gen.mag is an "abstract" view that represents the
-#   seal ring in diffusion and the nikon cross in metal1, and references
-#   the advSeal_6um_gen.gds file in the same directory as a GDS_FILE property.
+#
+#   generates a file "<layout_name>_drc.txt" containing a human-readable
+#   list of the DRC errors.
+# 	
 #-------------------------------------------------------------------------
 
 import subprocess
@@ -45,223 +21,15 @@
 import os
 import re
 
-def generate_sealring(width, height, target_dir, force, keep):
+# Work in progress
 
-    # All files of interest are listed below.
-
-    script = 'generate_gds.tcl'
-    tech = 's8seal_ring.tech'
-    corner = 'seal_ring_corner.mag'
-    abstract = 'seal_ring_corner_abstract.mag'
-    slots = 'sealring_slots.mag'
-    array = 'seal_ring_slots_array.mag'
-    nikon = 'nikon_sealring_shape.mag'
-    polygons = ['sr_polygon00007.mag',
-	    'sr_polygon00027.mag', 'sr_polygon00011.mag', 'sr_polygon00028.mag',
-	    'sr_polygon00001.mag', 'sr_polygon00015.mag', 'sr_polygon00031.mag',
-	    'sr_polygon00002.mag', 'sr_polygon00016.mag', 'sr_polygon00032.mag',
-	    'sr_polygon00003.mag', 'sr_polygon00019.mag', 'sr_polygon00035.mag',
-	    'sr_polygon00004.mag', 'sr_polygon00020.mag', 'sr_polygon00036.mag',
-	    'sr_polygon00005.mag', 'sr_polygon00023.mag', 'sr_polygon00039.mag',
-	    'sr_polygon00006.mag', 'sr_polygon00024.mag']
-
-
-    # Create temporary directory
-    if os.path.exists('temp'):
-        print('temp/ directory exists.  Please remove it before running.')
-        sys.exit(0)
-
-    os.makedirs('temp')
-    os.chdir('temp')
-
-    # Copy all .mag files, .magicrc file, and s8seal_ring.tech file to temp/
-    files_to_copy = polygons[:]
-    files_to_copy.append(nikon)
-    files_to_copy.append(slots)
-    files_to_copy.append(array)
-    files_to_copy.append(corner)
-    files_to_copy.append(abstract)
-    files_to_copy.append(tech)
-    files_to_copy.append(script)
-
-    for file in files_to_copy:
-        shutil.copy('../' + file, '.')
-
-    # Seal ring is placed 6um outside of the chip, so add 12um to width and height
-    fwidth = float(width) + 12
-    fheight = float(height) + 12
-
-    dbhwidth = int(fwidth * 100)
-    dbhheight = int(fheight * 100)
-
-    swidth = str(dbhwidth)
-    sheight = str(dbhheight)
-
-    swidthx5 = str(dbhwidth * 5)
-
-    dwidth = str(int(fwidth * 200))
-    dheight = str(int(fheight * 200))
-
-    # Modify every polygon to half width and height
-
-    for file in polygons:
-        with open(file, 'r') as ifile:
-            maglines = ifile.read().splitlines()
-
-        with open(file, 'w') as ofile:
-            for line in maglines:
-                newline = re.sub('51200', swidth, line)
-                newline = re.sub('51210', sheight, newline)
-                # NOTE: polygon 39 is at scale 10, not 2, due to
-                # corner positions of 45 degree angled geometry.
-                newline = re.sub('256000', swidthx5, newline)
-                print(newline, file=ofile)
-
-    # Abstract corner view gets the same treatment
-
-    qwidth = str(int(fwidth * 50))
-    qheight = str(int(fheight * 50))
-
-    with open(abstract, 'r') as ifile:
-        maglines = ifile.read().splitlines()
-
-    with open(abstract, 'w') as ofile:
-        for line in maglines:
-            newline = re.sub('25600', qwidth, line)
-            newline = re.sub('25605', qheight, newline)
-            print(newline, file=ofile)
-
-    # Slots arrays are recalculated to span the width and height
-
-    with open(array, 'r') as ifile:
-        maglines = ifile.read().splitlines()
-
-    slotsX = False
-    with open(array, 'w') as ofile:
-        for line in maglines:
-            newline = line
-            if 'slots_X' in line:
-                slotsX = True
-            elif 'array 0' in line:
-                if slotsX:
-                    nslots = int((fwidth - 25.0) / 25.0) - 1
-                    newline = 'array 0 ' + str(nslots) + ' 5000 0 0 430'
-                else:
-                    nslots = int((fheight - 25.0) / 25.0) - 1
-                    newline = 'array 0 ' + str(nslots) + ' 5000 0 0 430'
-
-            print(newline, file=ofile)
-
-    # Corner cell changes bounding boxes to half width and height.
-
-    with open(corner, 'r') as ifile:
-        maglines = ifile.read().splitlines()
-
-    slotsX = False
-    with open(corner, 'w') as ofile:
-        for line in maglines:
-            newline = re.sub('51200', swidth, line)
-            newline = re.sub('51210', sheight, newline)
-            print(newline, file=ofile)
-
-    # Create a new top-level layout called 'advSeal_6um_gen.mag'
-    # Mirrors uses in X and Y, and adds slots arrays at lower left
-    # and upper right
-
-    with open('advSeal_6um_gen.mag', 'w') as ofile:
-        print('magic', file=ofile)
-        print('tech s8seal_ring', file=ofile)
-        print('magscale 1 2', file=ofile)
-        print('timestamp 1584630000', file=ofile)
-
-        # Lower left original
-        print('use seal_ring_corner seal_ring_corner_0', file=ofile)
-        print('timestamp 1584562315', file=ofile)
-        print('transform 1 0 0 0 1 0', file=ofile)
-        print('box -30480 -30480 ' + swidth + ' ' + sheight, file=ofile)
-
-        # Mirrored in X
-        print('use seal_ring_corner seal_ring_corner_3', file=ofile)
-        print('timestamp 1584562315', file=ofile)
-        print('transform -1 0 ' + dwidth + ' 0 1 0', file=ofile)
-        print('box -30480 -30480 ' + swidth + ' ' + sheight, file=ofile)
-	
-        # Mirrored in Y
-        print('use seal_ring_corner seal_ring_corner_1', file=ofile)
-        print('timestamp 1584562315', file=ofile)
-        print('transform 1 0 0 0 -1 ' + dheight, file=ofile)
-        print('box -30480 -30480 ' + swidth + ' ' + sheight, file=ofile)
-
-        # Mirrored in both X and Y 
-        print('use seal_ring_corner seal_ring_corner_2', file=ofile)
-        print('timestamp 1584562315', file=ofile)
-        print('transform -1 0 ' + dwidth + ' 0 -1 ' + dheight, file=ofile)
-        print('box -30480 -30480 ' + swidth + ' ' + sheight, file=ofile)
-
-        # Lower left slot arrays (bottom and left sides slots)
-        print('use seal_ring_slots_array seal_ring_slots_array_0', file=ofile)
-        print('timestamp 1584629764', file=ofile)
-        print('transform 1 0 0 0 1 0', file=ofile)
-        print('box 285 285 ' + swidth + ' ' + sheight, file=ofile)
-
-        # Upper right slot arrays (top and right sides slots)
-        print('use seal_ring_slots_array seal_ring_slots_array_1', file=ofile)
-        print('timestamp 1584629764', file=ofile)
-        print('transform -1 0 ' + dwidth + ' 0 -1 ' + dheight, file=ofile)
-        print('box 285 285 ' + swidth + ' ' + sheight, file=ofile)
-
-        print('<< end >>', file=ofile)
-    
-    # Create a new abstract layout TO BE called 'advSeal_6um_gen.mag'
-    # This is the view in technology EFS8A.  Since there is already
-    # a cell with this name that is used to generate GDS, the cell
-    # will be called "seal_ring.mag" and copied to "advSeal_6um_gen.mag"
-    # in the target directory.
-
-    xwidth = str(dbhwidth)
-    xheight = str(dbhheight)
-
-    with open('seal_ring.mag', 'w') as ofile:
-        print('magic', file=ofile)
-        print('tech EFS8A', file=ofile)
-        print('timestamp 1584566829', file=ofile)
-
-        # Lower left original
-        print('use seal_ring_corner_abstract seal_ring_corner_abstract_0', file=ofile)
-        print('timestamp 1584566221', file=ofile)
-        print('transform 1 0 0 0 1 0', file=ofile)
-        print('box 0 0 ' + qwidth + ' ' + qheight, file=ofile)
-
-        # Mirrored in X
-        print('use seal_ring_corner_abstract seal_ring_corner_abstract_3', file=ofile)
-        print('timestamp 1584566221', file=ofile)
-        print('transform -1 0 ' + xwidth + ' 0 1 0', file=ofile)
-        print('box 0 0 ' + qwidth + ' ' + qheight, file=ofile)
-	
-        # Mirrored in Y
-        print('use seal_ring_corner_abstract seal_ring_corner_abstract_1', file=ofile)
-        print('timestamp 1584566221', file=ofile)
-        print('transform 1 0 0 0 -1 ' + xheight, file=ofile)
-        print('box 0 0 ' + qwidth + ' ' + qheight, file=ofile)
-
-        # Mirrored in both X and Y 
-        print('use seal_ring_corner_abstract seal_ring_corner_abstract_2', file=ofile)
-        print('timestamp 1584566221', file=ofile)
-        print('transform -1 0 ' + xwidth + ' 0 -1 ' + xheight, file=ofile)
-        print('box 0 0 ' + qwidth + ' ' + qheight, file=ofile)
-
-        print('<< properties >>', file=ofile)
-        print('string LEFview no_prefix', file=ofile)
-        print('string GDS_FILE advSeal_6um_gen.gds', file=ofile)
-        print('string GDS_START 0', file=ofile)
-        print('string FIXED_BBOX 0 0 ' + swidth + ' ' + sheight, file=ofile)
-
-        print('<< end >>', file=ofile)
+def run_full_drc(layout_name, output_file):
+    with open('run_magic_drc.tcl', 'w') as ofile:
 
     # Create the GDS of the seal ring
 
     mproc = subprocess.run(['magic', '-dnull', '-noconsole',
-	    'generate_gds.tcl'],
+	    'run_magic_drc.tcl'],
 	    stdin = subprocess.DEVNULL, stdout = subprocess.PIPE,
 	    stderr = subprocess.PIPE, universal_newlines = True)
     if mproc.stdout:
@@ -274,40 +42,7 @@
     if mproc.returncode != 0:
         print('ERROR:  Magic exited with status ' + str(mproc.returncode))
 
-    # Copy the GDS file and the abstract view to the target directory
-
-    os.chdir('..')
-
-    if not os.path.exists(target_dir):
-        os.makedirs(target_dir)
-
-    print('Installing files to ' + target_dir)
-    if force or not os.path.exists(target_dir + '/advSeal_6um_gen.gds'):
-        shutil.copy('temp/advSeal_6um_gen.gds', target_dir)
-    else:
-        print('ERROR: advSeal_6um_gen.gds already exists at target!  Use -force to overwrite.')
-    if force or not os.path.exists(target_dir + '/advSeal_6um_gen.mag'):
-        shutil.copy('temp/seal_ring.mag', target_dir + '/advSeal_6um_gen.mag')
-    else:
-        print('ERROR: advSeal_6um_gen.mag already exists at target!  Use -force to overwrite.')
-    if force or not os.path.exists(target_dir + '/seal_ring_corner_abstract.mag'):
-        shutil.copy('temp/seal_ring_corner_abstract.mag', target_dir)
-    else:
-        print('ERROR: seal_ring_corner_abstract.mag already exists at target!  Use -force to overwrite.')
-    
-    # Remove the temporary directory and its contents
-
-    if not keep:
-        shutil.rmtree('temp')
-    else:
-        print('Retaining generated files in temp/ directory')
-
-    # Done!
-    print('Done generating files advSeal_6um_gen.gds and advSeal_6um_gen.mag in ' + target_dir)
-    print('Place the seal ring cell in the final layout at (0um, 0um) before generating GDS.')
-    print('The top level layout minus seal ring must have a lower left corner of (6um, 6um)')
-
-# If called as main, run generate_sealring()
+# If called as main, run all DRC tests
 
 if __name__ == '__main__':
 
@@ -320,30 +55,22 @@
         else:
             arguments.append(item)
 
-    force = True if '-force' in options else False
-    keep = True if '-keep' in options else False
-    outer = True if '-outer' in options else False
-
-    # Need one argument:  path to verilog netlist
+    # Need one argument:  path to layout
     # If two arguments, then 2nd argument is the output file.
 
-    if len(arguments) == 3:
-        width = arguments[0]
-        height = arguments[1]
-        target_dir = arguments[2]
+    if len(arguments) < 3:
+        layout_root = arguments[1]
 
-        # Seal ring is 12um thick, so if "outer" option is used, subtract 12um
-        # from both width and height.
-        if outer:
-            width = str(float(width) - 12.0)
-            height = str(float(height) - 12.0)
-
-        generate_sealring(width, height, target_dir, force, keep)
+    if len(arguments == 1):
+        out_fileroot = layout_root + "_drc.txt"
     else:
-        print("Usage:  s8_gen_sealring.py <width> <height> <target_dir> [options]")
+        out_fileroot = arguments[2]
+
+    if len(arguments) < 3:
+        run_full_drc(layout_root, out_filename)
+    else:
+        print("Usage:  run_drc.py <layout_name> [<output_file>] [options]")
         print("Options:")
-        print("   -outer : Width and height are seal ring outer edge, not chip area")
-        print("   -force : Overwrite any existing files at <target_dir>")
-        print("   -keep :  Keep generated files in temp/ directory")
+        print("   (none)")
     
 
diff --git a/sky130/magic/sky130.tech b/sky130/magic/sky130.tech
index 498b73a..e9d0b99 100644
--- a/sky130/magic/sky130.tech
+++ b/sky130/magic/sky130.tech
@@ -5224,11 +5224,6 @@
  surround pdic/a *pdi 40 absence_illegal \
 	"P-diode overlap of N-diode contact < %d (licon.5a)"
 
- surround nsc/a *nsd 40 absence_illegal \
-	"N-tap overlap of N-tap contact < %d (licon.5a)"
- surround psc/a *psd 40 absence_illegal \
-	"P-tap overlap of P-tap contact < %d (licon.5a)"
-
  spacing psc/a allnactivenontap 60 touching_illegal \
 	"Min. space between P-tap contact and butting N diffusion < %d (licon.5b)"
  spacing nsc/a allpactivenontap 60 touching_illegal \
@@ -5257,11 +5252,6 @@
  surround mvpdic/a *mvpdi 40 absence_illegal \
 	"P-diode overlap of N-diode contact < %d (licon.5a)"
 
- surround mvnsc/a *mvnsd 40 absence_illegal \
-	"N-tap overlap of N-tap contact < %d (licon.5a)"
- surround mvpsc/a *mvpsd 40 absence_illegal \
-	"P-tap overlap of P-tap contact < %d (licon.5a)"
-
  spacing mvpsc/a allndiffmvnontap 60 touching_illegal \
 	"Min. space between P-tap contact and butting N diffusion < %d (licon.5b)"
  spacing mvnsc/a allpdiffmvnontap 60 touching_illegal \