Index: trunk/ppSim/src/ppSimMakeSky.c
===================================================================
--- trunk/ppSim/src/ppSimMakeSky.c	(revision 14463)
+++ trunk/ppSim/src/ppSimMakeSky.c	(revision 14657)
@@ -2,5 +2,12 @@
 
 // XXX add bounds to the inputs?
-bool ppSimMakeSky (psImage *signal, psImage *variance, psImage *expCorr, ppSimType type, pmConfig *config, pmFPA *fpa, pmChip *chip, pmCell *cell) {
+bool ppSimMakeSky (pmReadout *readout, psImage *expCorr, ppSimType type, pmConfig *config) {
+
+    psImage *signal = readout->image;
+    psImage *variance = readout->weight;
+
+    pmCell *cell = readout->parent;
+    pmChip *chip = cell->parent; 
+    pmFPA  *fpa  = chip->parent;
 
     float expTime = psMetadataLookupF32(NULL, config->arguments, "EXPTIME"); // Exposure time