Index: /trunk/psphot/src/psphotDefineFiles.c
===================================================================
--- /trunk/psphot/src/psphotDefineFiles.c	(revision 25982)
+++ /trunk/psphot/src/psphotDefineFiles.c	(revision 25983)
@@ -126,4 +126,13 @@
     }
 
+    if (psMetadataLookupPtr(NULL, config->arguments, "SRCTEXT")) {
+	// XXX cannot use pmFPAfileDefineFromArgs: this is explicitly a FITS-based I/O function
+	// supply the attach the 
+	if (!psphotLoadSRCTEXT(input->fpa, config)) {
+            psError(PSPHOT_ERR_CONFIG, false, "Failed to load PSPHOT.INPUT.TEXT");
+            return status;
+        }
+    }
+
     if (psMetadataLookupPtr(NULL, config->arguments, "PSPHOT.PSF")) {
         pmFPAfileBindFromArgs(&status, input, config, "PSPHOT.PSF.LOAD", "PSPHOT.PSF");
Index: /trunk/psphot/src/psphotLoadSRCTEXT.c
===================================================================
--- /trunk/psphot/src/psphotLoadSRCTEXT.c	(revision 25983)
+++ /trunk/psphot/src/psphotLoadSRCTEXT.c	(revision 25983)
@@ -0,0 +1,135 @@
+# include "psphotInternal.h"
+
+bool psphotLoadSRCTEXT (pmFPA *fpa, pmConfig *config) {
+
+    pmChip *chip;
+
+    // we have a psArray of filenames, but there is no information to tie the filenames to the
+    // corresponding chip/cell/readout.  Fortunately: (a) psphot only really operates on chips
+    // and (b) we can make some basic assumptions:
+
+    // 1) if there is only a single entry in the array, read the file and attach the results to
+    // each of the chip->analysis metadata entries (just an extra ref counter).
+
+    // 2) if there are multiple entries, the number of filenames must match the number of
+    // chips.
+
+    psArray *files = psMetadataLookupPtr(NULL, config->arguments, "SRCTEXT");
+
+    // XXX is this allowed?  how do we get an empty entry in arguments?
+    if (!files->n) return true;
+
+    // we use a default model type of GAUSS to define the sources
+    pmModelType modelType = pmModelClassGetType("PS_MODEL_GAUSS");
+
+    psArray *sourceArrays = psArrayAllocEmpty(files->n);
+    for (int i = 0; i < files->n; i++) {
+
+	char *filename = files->data[i];
+
+	// each file contains a list of X Y coordinates and nothing else?
+	FILE *f = fopen (filename, "r");
+	if (f == NULL) {
+            psError(PSPHOT_ERR_CONFIG, true, "Failed to read source text list %s", filename);
+	    return false;
+	}
+
+	double X, Y;
+
+	psArray *sources = psArrayAllocEmpty (100);
+	while (fscanf (f, "%lf %lf", &X, &Y) != EOF) {
+
+	    psEllipseAxes axes;
+	    
+	    pmSource *source = pmSourceAlloc ();
+	    pmModel *model = pmModelAlloc (modelType);
+	    source->modelPSF  = model;
+	    source->type = PM_SOURCE_TYPE_STAR;
+
+	    // NOTE: A SEGV here because "model" is NULL is probably caused by not initialising the models.
+	    psF32 *PAR = model->params->data.F32;
+	    psF32 *dPAR = model->dparams->data.F32;
+
+	    // NOTE: most of these values are irrelevant for loaded source positions
+	    source->seq       = 0;
+	    PAR[PM_PAR_XPOS]  = X;
+	    PAR[PM_PAR_YPOS]  = Y;
+	    dPAR[PM_PAR_XPOS] = 0.0;
+	    dPAR[PM_PAR_YPOS] = 0.0;
+	    axes.major        = 1.0;
+	    axes.minor        = 1.0;
+	    axes.theta        = 0.0;
+
+	    PAR[PM_PAR_SKY]   = 0.0;
+	    dPAR[PM_PAR_SKY]  = 0.0;
+	    source->sky       = PAR[PM_PAR_SKY];
+	    source->skyErr    = dPAR[PM_PAR_SKY];
+
+	    source->psfMag    = 0.0;
+	    source->errMag    = 0.0;
+	    source->apMag     = 0.0;
+
+	    PAR[PM_PAR_I0]    = 1.0;
+	    dPAR[PM_PAR_I0]   = 0.0;
+
+	    pmPSF_AxesToModel (PAR, axes);
+
+	    float peakFlux    = 1.0;
+
+	    source->peak = pmPeakAlloc(PAR[PM_PAR_XPOS], PAR[PM_PAR_YPOS], peakFlux, PM_PEAK_LONE);
+	    source->peak->flux = peakFlux;
+	    source->peak->dx   = dPAR[PM_PAR_XPOS];
+	    source->peak->dy   = dPAR[PM_PAR_YPOS];
+	    source->peak->xf   = PAR[PM_PAR_XPOS]; // the alloc function takes the pixel index,
+	    source->peak->yf   = PAR[PM_PAR_YPOS]; // but we know the pixel coordinate
+
+	    source->pixWeight = 1.0;
+	    source->crNsigma  = 0.0;
+	    source->extNsigma = 0.0;
+	    source->apRadius  = 0.0;
+
+	    model->chisq      = 0.0;
+	    model->nDOF       = 0;
+	    model->nPix       = 0;
+
+	    source->moments = pmMomentsAlloc ();
+	    source->moments->Mxx = 0.0;
+	    source->moments->Mxy = 0.0;
+	    source->moments->Myy = 0.0;
+
+	    source->mode = 0;
+	    
+	    psArrayAdd (sources, 100, source);
+	    psFree(source);
+	}
+	psArrayAdd (sourceArrays, 100, sources);
+	psFree (sources);
+    }
+
+    if (files->n == 1) {
+	psArray *sources = sourceArrays->data[0];
+	pmFPAview *view = pmFPAviewAlloc (0);
+	while ((chip = pmFPAviewNextChip (view, fpa, 1)) != NULL) {
+	    if (!chip->process) { continue; }
+	    psMetadataAddPtr (chip->analysis, PS_LIST_TAIL, "PSPHOT.SOURCES.TEXT", PS_DATA_ARRAY | PS_META_REPLACE, "loaded source from textfile", sources);
+	}
+	psFree (view);
+    } else {
+	int nSrc = 0;
+	pmFPAview *view = pmFPAviewAlloc (0);
+	while ((chip = pmFPAviewNextChip (view, fpa, 1)) != NULL) {
+	    if (!chip->process) { continue; }
+
+	    if (nSrc >= sourceArrays->n) {
+		psError(PSPHOT_ERR_CONFIG, true, "mismatch between number of source lists and number of chips (readouts)");
+		return false;
+	    }
+	    psArray *sources = sourceArrays->data[nSrc];
+	    psMetadataAddPtr (chip->analysis, PS_LIST_TAIL, "PSPHOT.SOURCES.TEXT", PS_DATA_ARRAY | PS_META_REPLACE, "loaded source from textfile", sources);
+	    nSrc ++;
+	}
+	psFree (view);
+    }
+    psFree (sourceArrays);
+    return true;
+}
Index: /trunk/psphot/src/psphotMergeSources.c
===================================================================
--- /trunk/psphot/src/psphotMergeSources.c	(revision 25982)
+++ /trunk/psphot/src/psphotMergeSources.c	(revision 25983)
@@ -4,4 +4,70 @@
                          PM_SOURCE_MODE_BADPSF | PM_SOURCE_MODE_DEFECT | PM_SOURCE_MODE_SATURATED | \
                          PM_SOURCE_MODE_CR_LIMIT | PM_SOURCE_MODE_EXT_LIMIT) // Mask to apply for PSF sources
+
+// merge the externally supplied sources with the existing sources.  mark them as having
+// mode PM_SOURCE_MODE_EXTERNAL
+bool psphotLoadExtSources (pmConfig *config, const pmFPAview *view, psArray *sources) {
+
+    psArray *extSourcesCMF = NULL;
+    psArray *extSourcesTXT = NULL;
+
+    // load data from input CMF file:
+    { 
+	pmReadout *readoutCMF = pmFPAfileThisReadout (config->files, view, "PSPHOT.INPUT.CMF");
+	if (!readoutCMF) goto loadTXT;
+
+	extSourcesCMF = psMetadataLookupPtr (NULL, readoutCMF->analysis, "PSPHOT.SOURCES");
+	if (extSourcesCMF) {
+	    for (int i = 0; i < extSourcesCMF->n; i++) {
+		pmSource *source = extSourcesCMF->data[i];
+		source->mode |= PM_SOURCE_MODE_EXTERNAL;
+
+		// the supplied peak flux needs to be re-normalized
+		source->peak->flux = 1.0;
+		source->peak->value = 1.0;
+
+		// drop the loaded source modelPSF
+		psFree (source->modelPSF);
+		source->modelPSF = NULL;
+	    }
+	    psphotMergeSources (sources, extSourcesCMF);
+	}
+    }
+
+loadTXT:
+
+    // load data from input TXT file:
+    { 
+	pmChip *chipTXT = pmFPAfileThisChip (config->files, view, "PSPHOT.INPUT");
+	if (!chipTXT) goto finish;
+
+	extSourcesTXT = psMetadataLookupPtr (NULL, chipTXT->analysis, "PSPHOT.SOURCES.TEXT");
+	if (extSourcesTXT) {
+	    for (int i = 0; i < extSourcesTXT->n; i++) {
+		pmSource *source = extSourcesTXT->data[i];
+		source->mode |= PM_SOURCE_MODE_EXTERNAL;
+
+		// drop the loaded source modelPSF
+		psFree (source->modelPSF);
+		source->modelPSF = NULL;
+	    }
+	    psphotMergeSources (sources, extSourcesTXT);
+	}
+    }
+
+finish:
+
+    if (!extSourcesTXT && !extSourcesTXT) {
+        psLogMsg ("psphot", 3, "no external sources for this readout");
+        return true;
+    }
+
+    int nCMF = extSourcesCMF ? extSourcesCMF->n : 0;
+    int nTXT = extSourcesTXT ? extSourcesTXT->n : 0;
+
+    psLogMsg ("psphot", 3, "%d external sources (%d cmf, %d text) merged to yield %ld total sources", 
+	      nCMF + nTXT, nCMF, nTXT, sources->n);
+    return true;
+}
 
 // add newly selected sources to the existing list of sources
@@ -12,45 +78,4 @@
         psArrayAdd (oldSources, 100, source);
     }
-    return true;
-}
-
-// merge the externally supplied sources with the existing sources.  mark them as having
-// mode PM_SOURCE_MODE_EXTERNAL
-bool psphotLoadExtSources (pmConfig *config, const pmFPAview *view, psArray *sources) {
-
-    // find the currently selected readout
-    pmReadout  *readout = pmFPAfileThisReadout (config->files, view, "PSPHOT.INPUT.CMF");
-    if (!readout) {
-        psLogMsg ("psphot", 3, "no external sources supplied");
-        return true;
-    }
-
-    psArray *extSources = psMetadataLookupPtr (NULL, readout->analysis, "PSPHOT.SOURCES");
-    if (!extSources) {
-        psLogMsg ("psphot", 3, "no external sources for this readout");
-        return true;
-    }
-
-    for (int i = 0; i < extSources->n; i++) {
-        pmSource *source = extSources->data[i];
-        source->mode |= PM_SOURCE_MODE_EXTERNAL;
-        pmModel *model = source->modelPSF;
-
-        float xpos = model->params->data.F32[PM_PAR_XPOS];
-        float ypos = model->params->data.F32[PM_PAR_YPOS];
-
-        source->peak = pmPeakAlloc(xpos, ypos, 1.0, PM_PEAK_LONE);
-        source->peak->xf = xpos;
-        source->peak->yf = ypos;
-        source->peak->flux = 1.0;
-
-        // drop the loaded source modelPSF
-        psFree (source->modelPSF);
-        source->modelPSF = NULL;
-    }
-
-    psphotMergeSources (sources, extSources);
-    psLogMsg ("psphot", 3, "%ld external sources merged to yield %ld total sources", extSources->n, sources->n);
-
     return true;
 }