From 1544159afce9b4fc23e6bf536c919467c24f96e1 Mon Sep 17 00:00:00 2001
From: lyrathorpe <iam@emmathe.dev>
Date: Mon, 6 Jul 2026 21:23:19 +0100
Subject: [PATCH] diag(inventory): try WL2:D (untried unit) then WL2:A; read +
 dump

---
 code/inventory/scan.c | 46 +++++++++++++++++++++++++++----------------
 1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/code/inventory/scan.c b/code/inventory/scan.c
index bdc062e..e9be4fd 100644
--- a/code/inventory/scan.c
+++ b/code/inventory/scan.c
@@ -1,32 +1,45 @@
 /*
- * scan.c - Phase 1 barcode diagnostic: read the integral laser via WL2:A.
+ * scan.c - Phase 1 barcode diagnostic: read the integral laser via WL2:D.
  *
- * demman reports the scanner's port as WL2:A (decoder "Symbol"), so the
- * integral MX laser is driven by the resident WL2 driver - not BAR:, not
- * TTY:D. WL2 is not documented in this SDK, so this opens WL2:A and dumps what
- * a read returns, to learn its format. It uses the barcode-style read
- * (p_iow(pcb, P_FREAD, buf), count typically in buf[0]) and prints the first
- * bytes both as decimal and as text.
- *
- * Press the scan key to trigger a scan while the read is waiting.
+ * The MX ROM shows the scanner port is WL2 with units A and D, decoder
+ * "Symbol2" (Workabout MX scanner). WL2:A returned -9 (in use); WL2:D (the
+ * top-slot position, as TTY:D was) is untried. This opens WL2:D (falling back
+ * to WL2:A), and if a channel opens, reads it barcode-style
+ * (p_iow(pcb, P_FREAD, buf)) and dumps the bytes. Press the scan key to fire.
  */
 #include <plib.h>
 
+#define NU 2
+
 GLDEF_C INT main(VOID)
 {
     VOID *chan;
     UBYTE buf[256];
-    INT   err, r, i, cnt;
+    INT   r, i, opened;
+    UINT  k;
 
-    err = p_open(&chan, "WL2:A", (UINT)-1);
-    p_printf("open WL2:A: %d\n", err);
-    if (err < 0) {
-        p_printf("Press a key to exit.\n");
+    static TEXT *names[NU] = { "WL2:D", "WL2:A" };
+    INT results[NU];
+
+    opened = -1;
+    for (k = 0; k < NU; k++) {
+        r = p_open(&chan, names[k], (UINT)-1);
+        results[k] = r;
+        if (r >= 0 && opened < 0)
+            opened = k;
+    }
+
+    for (k = 0; k < NU; k++)
+        p_printf("open %s: %d\n", names[k], results[k]);
+
+    if (opened < 0) {
+        p_printf("\nNothing opened. Press a key.\n");
         p_getch();
         return 1;
     }
 
-    p_printf("Scan now (press the scan key). Dumping reads:\n\n");
+    p_open(&chan, names[opened], (UINT)-1);   /* reopen the winner */
+    p_printf("\nOpened %s. Scan (press scan key). Dumping:\n\n", names[opened]);
 
     for (;;) {
         r = p_iow(chan, P_FREAD, buf);
@@ -34,8 +47,7 @@ GLDEF_C INT main(VOID)
             p_printf("read status %d\n", r);
             continue;
         }
-        cnt = buf[0];
-        p_printf("r=%d b0=%d:", r, cnt);
+        p_printf("r=%d b0=%d:", r, buf[0]);
         for (i = 0; i < 24 && i < 256; i++)
             p_printf(" %d", buf[i]);
         p_printf("  \"");