diff --git a/sbom.json b/sbom.json
index 7e381df..dd9598c 100644
--- a/sbom.json
+++ b/sbom.json
@@ -7,7 +7,7 @@
       "bom-ref": "pkg:nim/syndicate_utils",
       "name": "syndicate_utils",
       "description": "Utilites for Syndicated Actors and Synit",
-      "version": "20240606",
+      "version": "20240610",
       "authors": [
         {
           "name": "Emery Hemingway"
diff --git a/src/esc_printer_driver.nim b/src/esc_printer_driver.nim
index c7aaf03..5348a5c 100644
--- a/src/esc_printer_driver.nim
+++ b/src/esc_printer_driver.nim
@@ -30,7 +30,7 @@ proc flush(printer: Printer) {.asyncio.} =
   while printer.buffer.len > 0:
     let n = printer.device.write(printer.buffer)
     if n > 0:
-      printer.buffer.delete(0, n)
+      printer.buffer.delete(0..<n)
     elif n < 0:
       osLastError().osErrorMsg().quit()
   printer.isBusy = false
@@ -85,20 +85,27 @@ method retract(printer: Printer; t: Turn; h: Handle) =
   elif printer.subscriptHandles.contains h:
     printer.retract(printer.subscriptHandles, CancelAltScript, h)
 
-let devicePath = paramStr(1)
+
+proc devicePath: string =
+  if paramCount() < 1:
+    quit "missing path to printer device file"
+  if paramCount() > 1:
+    quit "too many command line parameters"
+  paramStr(1)
 
 proc openPrinter(turn: Turn): Printer =
   new result
   result.facet = turn.facet
-  let fd = posix.open(devicePath, O_WRONLY or O_NONBLOCK, 0)
+  let fd = posix.open(devicePath(), O_WRONLY or O_NONBLOCK, 0)
   if fd < 0: osLastError().osErrorMsg().quit()
   result.device = newAsyncFile(FD fd)
   result.write(InitializePrinter)
 
-runActor(devicePath) do (turn: Turn):
-  let printer = turn.newCap openPrinter(turn)
+runActor(devicePath()) do (turn: Turn):
+  let printer = openPrinter(turn)
   resolveEnvironment(turn) do (turn: Turn; relay: Cap):
-    during(turn, relay, grabWithinType(Resolve)) do (step: Value; cont: Cap):
-      if step.isRecord("printer"):
-        # Publish for any <printer> step.
-        discard publish(turn, cont, ResolvedAccepted(responderSession: printer))
+    let pat = Resolve?:{0: matchRecord("printer"), 1: grab()}
+    during(turn, relay, pat) do (cont: Cap):
+      # Publish for any <printer> step.
+      discard publish(turn, cont, ResolvedAccepted(
+          responderSession: turn.newCap(printer)))