diff --git a/Makefile b/Makefile
index a9f72194..46568abe 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,10 @@ DEFAULT_CONFIG_LOCATION = 454656
 CONFIG_LOCATION = 458752
 HTML_LOCATION = 262144
 
+# Startup configuration embedded in the image. Override it to build a specific
+# machine with its own configuration: make MACHINE=<name> CONFIG=<file>
+CONFIG ?= config.txt
+
 SDCC_TOOLCHAIN = sdcc-$(shell cat sdcc/* | cksum | cut -d' ' -f1)
 SDCC_PREFIX = toolchain/$(SDCC_TOOLCHAIN)
 ifeq ($(origin CC),default)
@@ -56,6 +60,7 @@ ifndef BUILDDIR
 	BUILDDIR = output/$(MACHINE)
 endif
 
+CONFIG_STAMP := $(BUILDDIR)/.config
 VERSION_HEADER := version.h
 
 GIT_VERSION := $(shell git rev-parse --short HEAD)
@@ -78,9 +83,10 @@ BUILD_DATE := $(shell date -u -d @$(SOURCE_DATE_EPOCH) +"%Y-%m-%d %H:%M:%S" 2>/d
 	|| date -u -r $(SOURCE_DATE_EPOCH) +"%Y-%m-%d %H:%M:%S")
 endif
 
-# $(MACHINE_SRC) is listed here so an unknown $MACHINE fails before anything else
-# is built, including the tools/ subdirectory.
-all: create_build_dir $(VERSION_HEADER) $(MACHINE_SRC) $(SUBDIRS) $(BUILDDIR)/rtlplayground-$(FILENAME_EXTENSION).bin
+# $(MACHINE_SRC) and $(CONFIG) are listed here so an unknown $MACHINE or a
+# missing config file fails before anything else is built, including the tools/
+# subdirectory.
+all: create_build_dir $(VERSION_HEADER) $(MACHINE_SRC) $(CONFIG) $(SUBDIRS) $(BUILDDIR)/rtlplayground-$(FILENAME_EXTENSION).bin
 
 bank_size:
 	tools/bank_occupancy.sh "$(MACHINE)"
@@ -101,6 +107,12 @@ $(MACHINE_SRC):
 	@echo "       Example: make MACHINE=KP_9000_6XHML_X2" >&2
 	@false
 
+# Fail with a clear message when CONFIG names a file that does not exist.
+$(CONFIG):
+	@echo "ERROR: CONFIG='$(CONFIG)' does not exist." >&2
+	@echo "       Point CONFIG at a configuration file, or omit it to use config.txt." >&2
+	@false
+
 # Keep the per-machine definition in first position to fail immediately on an
 # invalid $MACHINE value
 SRCS = \
@@ -220,6 +232,12 @@ FORCE:
 $(CCFLAGS_STAMP): FORCE | create_build_dir
 	@echo '$(CC_FLAGS)' | cmp -s - $@ 2>/dev/null || echo '$(CC_FLAGS)' > $@
 
+# The same for $(CONFIG): its path is stamped so switching to a config file
+# older than the image still rebuilds it, while $(CONFIG) itself as a normal
+# prerequisite covers edits to the selected file.
+$(CONFIG_STAMP): FORCE | create_build_dir
+	@echo '$(CONFIG)' | cmp -s - $@ 2>/dev/null || echo '$(CONFIG)' > $@
+
 $(BUILDDIR)/%.rel: %.c $(CCFLAGS_STAMP) | create_build_dir html_data.h
 	$(CC) -MMD $(CC_FLAGS) -o $@ -c $<
 
@@ -233,11 +251,11 @@ $(BUILDDIR)/rtlplayground.ihx: $(OBJS) $(BUILDDIR)/crtbank.rel $(BUILDDIR)/crc16
 $(BUILDDIR)/rtlplayground.img: $(BUILDDIR)/rtlplayground.ihx
 	objcopy --input-target=ihex -O binary $< $@
 
-$(BUILDDIR)/rtlplayground-$(FILENAME_EXTENSION).bin: $(BUILDDIR)/rtlplayground.img | tools
+$(BUILDDIR)/rtlplayground-$(FILENAME_EXTENSION).bin: $(BUILDDIR)/rtlplayground.img $(CONFIG) $(CONFIG_STAMP) | tools
 	if [ -e $@ ]; then rm $@; fi
-	tools/$(BUILDDIR)/imagebuilder -i $^ $@
-	tools/$(BUILDDIR)/fileadder -a $(DEFAULT_CONFIG_LOCATION) -s $(IMAGESIZE) -d config.txt $@
-	tools/$(BUILDDIR)/fileadder -a $(CONFIG_LOCATION) -s $(IMAGESIZE) -d config.txt $@
+	tools/$(BUILDDIR)/imagebuilder -i $(BUILDDIR)/rtlplayground.img $@
+	tools/$(BUILDDIR)/fileadder -a $(DEFAULT_CONFIG_LOCATION) -s $(IMAGESIZE) -d "$(CONFIG)" $@
+	tools/$(BUILDDIR)/fileadder -a $(CONFIG_LOCATION) -s $(IMAGESIZE) -d "$(CONFIG)" $@
 	tools/$(BUILDDIR)/fileadder -a $(HTML_LOCATION) -s $(IMAGESIZE) -z -d $(HTML_MIN) -b BANK1 $@
 	tools/$(BUILDDIR)/crc_calculator -u $@
 	ln -sf $(MACHINE)/rtlplayground-$(FILENAME_EXTENSION).bin $(BUILDDIR)/../rtlplayground.bin
diff --git a/README.md b/README.md
index 25c0a02d..0deddc6f 100644
--- a/README.md
+++ b/README.md
@@ -127,6 +127,13 @@ The name selects the board definition `machine/<name>.c`; `make` without a
 `MACHINE` value stops with an error listing what is expected. If your board is
 not in the list yet, see [Adding a new device](doc/adding-a-device.md).
 
+To embed a machine-specific startup configuration, pass `CONFIG`:
+```
+make MACHINE=DEFAULT_8C_1SFP CONFIG=configs/DEFAULT_8C_1SFP.txt
+```
+`CONFIG` defaults to `config.txt`; the selected file is embedded in the image
+and changing it triggers a rebuild.
+
 > [!TIP]
 > You can write configuration parameters in config.txt (see below) in order your switch to get
 > straight at the first boot, a correct IP configuration.
diff --git a/html/app.js b/html/app.js
index b4c1f459..9e8432fa 100644
--- a/html/app.js
+++ b/html/app.js
@@ -954,6 +954,7 @@ function byPort(a){return a.sort(function(x,y){return x.portNum-y.portNum})}
 function pollStatus(){
   return getJSON("/status.json").then(function(s){
     byPort(s);
+    S.ports=s;
     var now=Date.now();
     if(!S.n){
       S.n=s.length;
@@ -975,7 +976,7 @@ function pollStatus(){
         };
       });
     }
-    S.prev=s;S.prevT=now;S.ports=s;
+    S.prev=s;S.prevT=now;
     updateStrip();
     var hk=tabHooks[curTab];
     if(hk&&hk.status)hk.status();
diff --git a/html/index.html b/html/index.html
index 2660cfbc..5695f819 100644
--- a/html/index.html
+++ b/html/index.html
@@ -125,12 +125,20 @@ label.row span.lb{width:110px;flex:none;color:var(--fg2);font-size:13px}
 .port .pn{font-weight:650;font-size:12px}
 .port .ps{font-size:9px;color:var(--fg2);display:block;line-height:1.2}
 .port .jack{
-  display:block;width:16px;height:10px;margin:2px auto 1px;border-radius:2px;
-  border:2px solid var(--fg2);border-top-width:4px;opacity:.55;
+  display:block;width:21px;height:12px;margin:4px auto 2px;border-radius:2px;
+  border:2px solid var(--fg2);border-top-width:8px;opacity:.55;position:relative;
 }
-.port.sfp .jack{width:24px;height:9px;border-top-width:3px}
+.port .jack:before{content:"";
+  position:absolute;bottom:100%;left:50%;transform:translateX(-50%);
+  width:6px;height:5px;margin-bottom:7px;border-radius: 1px 1px 0 0;
+  background-color:var(--fg2);
+}
+.port.sfp .jack{width:24px;height:16px;margin:0 auto 2px;border-top-width:5px}
+.port.sfp .jack:before{width:10px;margin-bottom:2px;border-radius:0 0 1px 1px;background-color:var(--panel2)}
 .port.up{border-color:var(--pc);background:color-mix(in srgb,var(--pc) 10%,var(--panel2))}
 .port.up .jack{border-color:var(--pc);opacity:1}
+.port.up .jack:before{background-color:var(--pc)}
+.port.up.sfp .jack:before{background-color:color-mix(in srgb,var(--pc) 10%,var(--panel2))}
 .port.up .ps{color:var(--pc);font-weight:600}
 .port.dis{opacity:.45;border-style:dashed}
 .badge{font-size:11px;font-weight:600;border-radius:10px;padding:1px 8px;background:var(--panel2);color:var(--fg2)}