diff --git a/fuzzers/030-iob/Makefile b/fuzzers/030-iob/Makefile
index 9216a598..c36191bd 100644
--- a/fuzzers/030-iob/Makefile
+++ b/fuzzers/030-iob/Makefile
@@ -1,20 +1,30 @@
 N := 1
 include ../fuzzer.mk
 
-SEGDATAS=$(addsuffix /segdata_liob33.txt,$(SPECIMENS))
+SEGDATAS_L=$(addsuffix /segdata_liob33.txt,$(SPECIMENS))
+SEGDATAS_R=$(addsuffix /segdata_riob33.txt,$(SPECIMENS))
 
-database: build/segbits_liob33.db
+database: build/segbits_liob33.db build/segbits_riob33.db
 
 build/segbits_liob33.rdb: $(SPECIMENS_OK)
-	${XRAY_SEGMATCH} -o build/segbits_liob33.rdb $(SEGDATAS)
+	${XRAY_SEGMATCH} -o build/segbits_liob33.rdb $(SEGDATAS_L)
 
 build/segbits_liob33.db: build/segbits_liob33.rdb
 	${XRAY_DBFIXUP} --db-root build --zero-db bits.dbf --seg-fn-in $^ --seg-fn-out $@
-	${XRAY_MASKMERGE} build/mask_liob33.db $(SEGDATAS)
+	${XRAY_MASKMERGE} build/mask_liob33.db $(SEGDATAS_L)
+
+build/segbits_riob33.rdb: $(SPECIMENS_OK)
+	${XRAY_SEGMATCH} -o build/segbits_riob33.rdb $(SEGDATAS_R)
+
+build/segbits_riob33.db: build/segbits_riob33.rdb
+	${XRAY_DBFIXUP} --db-root build --zero-db bits.dbf --seg-fn-in $^ --seg-fn-out $@
+	${XRAY_MASKMERGE} build/mask_riob33.db $(SEGDATAS_R)
 
 pushdb:
 	${XRAY_MERGEDB} liob33 build/segbits_liob33.db
+	${XRAY_MERGEDB} riob33 build/segbits_riob33.db
 	${XRAY_MERGEDB} mask_liob33 build/mask_liob33.db
+	${XRAY_MERGEDB} mask_riob33 build/mask_riob33.db
 
 .PHONY: database pushdb
 
diff --git a/fuzzers/030-iob/bits.dbf b/fuzzers/030-iob/bits.dbf
index 57741c98..cb2dab5c 100644
--- a/fuzzers/030-iob/bits.dbf
+++ b/fuzzers/030-iob/bits.dbf
@@ -1 +1,2 @@
-38_98 39_97 39_99,LIOB33.IOB_Y1.PULLTYPE.PULLDOWN
+38_92 39_93 38_94,LIOB33.IOB_Y0.PULLTYPE.PULLDOWN
+39_33 38_34 39_35,LIOB33.IOB_Y1.PULLTYPE.PULLDOWN
diff --git a/fuzzers/030-iob/top.py b/fuzzers/030-iob/top.py
index 147a8b07..575193de 100644
--- a/fuzzers/030-iob/top.py
+++ b/fuzzers/030-iob/top.py
@@ -8,6 +8,7 @@ import random
 random.seed(int(os.getenv("SEED"), 16))
 from prjxray import util
 from prjxray import verilog
+from prjxray.db import Database
 
 
 def gen_iobs():
@@ -17,10 +18,15 @@ def gen_iobs():
     IOB33: not a diff pair. Relatively rare (at least in ROI...2 of them?)
     Focus on IOB33S to start
     '''
-    for _tile_name, site_name, site_type in util.get_roi().gen_sites(
-            #['IOB33', 'IOB33S', 'IOB33M']):
-        ['IOB33S']):
-        yield site_name, site_type
+    db = Database(util.get_db_root())
+    grid = db.grid()
+    for tile_name in sorted(grid.tiles()):
+        loc = grid.loc_of_tilename(tile_name)
+        gridinfo = grid.gridinfo_at_loc(loc)
+
+        for site_name, site_type in gridinfo.sites.items():
+            if site_type in ['IOB33S', 'IOB33M']:
+                yield site_name, site_type
 
 
 def write_pins(ports):