From 2731d22266e5728b69c9da39ed63bb231ed5a6e5 Mon Sep 17 00:00:00 2001
From: lyrathorpe <iam@emmathe.dev>
Date: Mon, 6 Jul 2026 21:52:26 +0100
Subject: [PATCH] feat(inventory): WL2:D trigger(6/7)+p_read loop with length +
 re-trigger

---
 code/inventory/scan.c | 47 +++++++++++++++++++------------------------
 1 file changed, 21 insertions(+), 26 deletions(-)

diff --git a/code/inventory/scan.c b/code/inventory/scan.c
index a1d4e97..a7a3430 100644
--- a/code/inventory/scan.c
+++ b/code/inventory/scan.c
@@ -1,27 +1,23 @@
 /*
- * scan.c - Phase 1: read the integral laser via WL2:D (reverse-engineered init).
+ * scan.c - Phase 1: WL2:D scanner, trigger + read loop (reverse-engineered).
  *
- * From disassembling SCANNER.DYL in the MX ROM, the scanner is driven over the
- * SIBO I/O executive (int 0xCF), i.e. the p_iow(chan, func, ...) layer. After
- * opening WL2:D the driver is enabled with two control ops (function codes 6
- * then 7 on the channel), after which decoded barcodes can be read. Decoded
- * output is terminated by CR LF (default Symbol2 postamble 0x0D 0x0A).
- *
- * This is the first RE-based attempt: the enable-then-read path. The full config
- * download (cl=0x0C command-byte writes) is not replicated here - if the driver
- * applies Symbol2 defaults on open, enable+read should suffice; if not, we add
- * the config writes next. Press the scan key to fire the laser.
+ * Confirmed from the previous build: opening WL2:D then issuing control ops 6
+ * and 7 triggers a scan (laser fires, green good-read LED). What was missing was
+ * the read: a bare p_iow(chan, P_FREAD, buf) passes no length. This uses p_read
+ * (which passes &len) to collect the decoded result, and re-triggers (ops 6/7)
+ * each iteration so successive scans work without relying on the scan key.
+ * Decoded output is CR/LF-terminated (default Symbol2 postamble).
  */
 #include <plib.h>
 
-#define WL2_ENABLE1 6
-#define WL2_ENABLE2 7
+#define WL2_TRIG1 6
+#define WL2_TRIG2 7
 
 GLDEF_C INT main(VOID)
 {
     VOID *chan;
     UBYTE buf[256];
-    INT   err, r, i;
+    INT   err, n, i;
 
     err = p_open(&chan, "WL2:D", (UINT)-1);
     p_printf("open WL2:D: %d\n", err);
@@ -31,24 +27,23 @@ GLDEF_C INT main(VOID)
         return 1;
     }
 
-    r = p_iow(chan, WL2_ENABLE1);
-    p_printf("enable op6: %d\n", r);
-    r = p_iow(chan, WL2_ENABLE2);
-    p_printf("enable op7: %d\n", r);
-
-    p_printf("\nScan a barcode (press scan key). Dumping reads:\n\n");
+    p_printf("Present a barcode under the laser. Reads:\n\n");
 
     for (;;) {
-        r = p_iow(chan, P_FREAD, buf);
-        if (r < 0) {
-            p_printf("read status %d\n", r);
+        p_iow(chan, WL2_TRIG1);            /* trigger a scan */
+        p_iow(chan, WL2_TRIG2);
+        n = p_read(chan, buf, sizeof(buf));   /* collect decoded result (with len) */
+        if (n < 0) {
+            p_printf("read %d\n", n);
             continue;
         }
-        p_printf("r=%d b0=%d:", r, buf[0]);
-        for (i = 0; i < 24 && i < 256; i++)
+        if (n == 0)
+            continue;
+        p_printf("n=%d:", n);
+        for (i = 0; i < n && i < 40; i++)
             p_printf(" %d", buf[i]);
         p_printf("  \"");
-        for (i = 0; i < 24 && i < 256; i++)
+        for (i = 0; i < n && i < 40; i++)
             p_putch(buf[i] >= ' ' ? buf[i] : '.');
         p_printf("\"\n");
     }