From 2e88f63a73d0c5f860f18d8d536f20cac07f7de3 Mon Sep 17 00:00:00 2001
From: David Hale <dhale@caltech.edu>
Date: Tue, 13 Oct 2026 11:23:51 -0700
Subject: [PATCH 1/2] bugfix: emulator answers FRAME before ACF is loaded as
 real Archon does

starts in the BIGBUF=0 buffer state through set_bigbuf(),
which the BIGBUF handler now also calls
---
 emulator/emulator-archon.cpp | 44 ++++++++++++++++++++++++------------
 emulator/emulator-archon.h   |  1 +
 2 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/emulator/emulator-archon.cpp b/emulator/emulator-archon.cpp
index b84dd35..df186cd 100644
--- a/emulator/emulator-archon.cpp
+++ b/emulator/emulator-archon.cpp
@@ -77,6 +77,11 @@ namespace Archon {
       exit(1);
     }
 
+    // Start with the frame buffers a real Archon reports at power-up,
+    // before any ACF has been loaded.
+    //
+    this->set_bigbuf( false );
+
     struct timespec ts;     // container for the time
     if ( clock_gettime( CLOCK_REALTIME, &ts ) != 0 ) {
       this->init_time = 0;
@@ -345,11 +350,6 @@ namespace Archon {
     std::string timenow;
     std::stringstream framestr;
 
-    if ( this->image->activebufs == -1 ) {
-      std::cerr << get_timestamp() << function << "ERROR: activebufs undefined. Check that an ACF was loaded and that it contains BIGBUF=x\n";
-      return ERROR;
-    }
-
     this->timer_report( this->frame.timer );
 
     framestr << "TIMER=" << this->frame.timer << " "
@@ -497,6 +497,29 @@ namespace Archon {
   /***** Interface:fetch_data *************************************************/
 
 
+  /***** Interface::set_bigbuf ************************************************/
+  /**
+   * @brief      sets the frame buffer layout selected by BIGBUF
+   * @param[in]  bigbuf  true for BIGBUF=1, false for BIGBUF=0
+   *
+   * Sets the number of active frame buffers and their base addresses.
+   *
+   */
+  void Interface::set_bigbuf( bool bigbuf ) {
+    this->bigbuf = bigbuf;
+    this->image->activebufs = ( this->bigbuf ? 2 : 3 );
+    this->frame.bufbase.at(0) = 0xA0000000;
+    if ( this->bigbuf ) {
+      this->frame.bufbase.at(1) = 0xD0000000;
+    }
+    else {
+      this->frame.bufbase.at(1) = 0xC0000000;
+      this->frame.bufbase.at(2) = 0xE0000000;
+    }
+  }
+  /***** Interface::set_bigbuf ************************************************/
+
+
   /***** Interface:wconfig ****************************************************/
   /**
    * @brief      handles the incoming WCONFIG command
@@ -593,16 +616,7 @@ namespace Archon {
         // Some keywords in this category are used to assign certain class variables
         //
         if ( key == "BIGBUF" ) {
-          this->bigbuf = ( std::stoi(value)==1 ? true : false );
-          this->image->activebufs = ( this->bigbuf ? 2 : 3 );
-          this->frame.bufbase.at(0) = 0xA0000000;
-          if ( this->bigbuf ) {
-            this->frame.bufbase.at(1) = 0xD0000000;
-          }
-          else {
-            this->frame.bufbase.at(1) = 0xC0000000;
-            this->frame.bufbase.at(2) = 0xE0000000;
-          }
+          this->set_bigbuf( std::stoi(value)==1 ? true : false );
         }
 
         else if ( key == "TAPLINES" ) {
diff --git a/emulator/emulator-archon.h b/emulator/emulator-archon.h
index 8e718df..9bc034b 100644
--- a/emulator/emulator-archon.h
+++ b/emulator/emulator-archon.h
@@ -131,6 +131,7 @@ namespace Archon {
       long wconfig(std::string buf);         //!< 
       long rconfig(std::string buf, std::string &retstring);         
       long write_parameter(std::string buf);
+      void set_bigbuf( bool bigbuf );        //!< sets frame buffer count and base addresses
       static void dothread_expose( Archon::Interface &iface, int numexpose );
 
 // TODO ***** below here need to check what's needed **********************************************************

From 4530ce52f94c9cb77b1106f98525bba8df4f4bbb Mon Sep 17 00:00:00 2001
From: David Hale <dhale@caltech.edu>
Date: Tue, 13 Oct 2026 11:34:42 -0700
Subject: [PATCH 2/2] bugfix: open fails when FRAME fails instead of replying
 DONE

---
 camerad/archon_controller.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/camerad/archon_controller.cpp b/camerad/archon_controller.cpp
index 9f26979..c4f2a3d 100644
--- a/camerad/archon_controller.cpp
+++ b/camerad/archon_controller.cpp
@@ -366,7 +366,9 @@ namespace Camera {
 
     // Ensures these values are set on startup
     //
-    this->get_frame_status();
+    if (this->get_frame_status() != NO_ERROR) {
+      throw std::runtime_error("getting FRAME status");
+    }
 
     if (this->lastframe==0) {
       for (int i=0; i<MAXNBUFS; ++i) {