code/inventory/scan.c

@@ -1,13 +1,14 @@
 /*
  * scan.c - Phase 1 barcode diagnostic for the Workabout MX integral laser.
  *
- * Loads the EAN/UPC decoder LDD (BAREAN.LDD), opens the decoder device (BAR:)
- * and dumps every byte of each read: the decimal value of each byte plus a
- * printable rendering. This shows exactly what the decoder delivers for a UPC
- * (length, any prefix/type byte, terminator) so the reader and Phase 2 key
- * format can be built on fact rather than assumption.
+ * Loads the EAN/UPC decoder LDD (BAREAN.LDD), opens the decoder device (BAR:),
+ * and dumps every byte of each read so the decoded format (length, any prefix
+ * or type byte, terminator) can be confirmed.
  *
- * Blocking reads; exit via the System screen.
+ * The load and open results are printed and then a key is waited for BEFORE
+ * anything else, so the numbers stay on screen even if the open fails (a failed
+ * open would otherwise return instantly and the System screen would wipe the
+ * message). Blocking I/O throughout; exit via the System screen.
  */
 #include <plib.h>
 #include "bcode.h"
@@ -16,18 +17,23 @@ GLDEF_C INT main(VOID)
 {
     VOID *chan;
     UBYTE buf[64];
-    INT   err, n, i;
+    INT   loadErr, openErr, n, i;
 
-    err = bcodeLoad();
-    /* 0 = loaded now; E_FILE_EXIST = already loaded. Anything else is a problem
-       (e.g. E_FILE_NXIST = BAREAN.LDD not found on the device). */
-    p_printf("load %s.LDD: %d\n", BCODE_LDD, err);
+    loadErr = bcodeLoad();
+    openErr = bcodeOpen(&chan);
 
-    if ((err = bcodeOpen(&chan)) < 0) {
-        p_printf("open %s failed: %d\n", BCODE_DEV, err);
+    /* Show both results and hold the screen until a key is pressed. */
+    p_printf("load %s.LDD : %d\n", BCODE_LDD, loadErr);
+    p_printf("open %s    : %d\n", BCODE_DEV, openErr);
+    p_printf("\n(0 = ok; for load, an 'already loaded' error is also ok)\n");
+    p_printf("Press a key to continue...\n");
+    p_getch();
+
+    if (openErr < 0)
         return 1;
-    }
-    p_printf("%s open. Scan a barcode.\n\n", BCODE_DEV);
+
+    p_printf("\n%s open. Scan a barcode. Exit via the System screen.\n\n",
+             BCODE_DEV);
 
     for (;;) {
         n = p_read(chan, buf, sizeof(buf));