From b935a173e5a3a59f89044dc686d26f84d8e47cd1 Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Thu, 5 Jan 2017 09:36:17 -0800
Subject: [PATCH] PDP11, All VAX: Fix TU58 device (TDC) failure when not
 ATTACHED

---
 PDP11/pdp11_td.c | 10 +++++++---
 PDP11/pdp11_td.h |  2 ++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/PDP11/pdp11_td.c b/PDP11/pdp11_td.c
index 13a445ba..194c4411 100644
--- a/PDP11/pdp11_td.c
+++ b/PDP11/pdp11_td.c
@@ -921,7 +921,7 @@ switch (opcode) {
 
     case TD_OPDAT:
         if (ctlr->p_state != TD_WRITE1) {                   /* expecting data? */
-            sim_printf("TU58 protocol error 1\n");
+            sim_debug (TDDEB_ERR, ctlr->dptr, "td_process_packet() Opcode=%s(%d) - TU58 protocol error 1 - Not Expecting Data\n", opcode_name, opcode);
             return;
             }
         if (ctlr->ibptr < 2) {                              /* whole packet read? */
@@ -934,7 +934,7 @@ switch (opcode) {
 
     case TD_OPCMD:
         if (ctlr->p_state != TD_IDLE) {                     /* expecting command? */
-            sim_printf("TU58 protocol error 2\n");
+            sim_debug (TDDEB_ERR, ctlr->dptr, "td_process_packet() Opcode=%s(%d) - TU58 protocol error 2 - Not Expecting Command\n", opcode_name, opcode);
             return;
             }
         if (ctlr->ibptr < 2) {                              /* whole packet read? */
@@ -1021,6 +1021,10 @@ switch (opcode) {
             sim_debug (TDDEB_TRC, ctlr->dptr, "td_process_packet(OPBOO) Unit=%d\n", ctlr->ibuf[4]);
             ctlr->unitno = ctlr->ibuf[1];
             fbuf = (int8 *)ctlr->uptr[ctlr->unitno].filebuf;
+            if (fbuf == NULL) {                         /* attached? */
+                sim_debug (TDDEB_ERR, ctlr->dptr, "td_process_packet(OPBOO) Unit=%d - NOT ATTACHED\n", ctlr->ibuf[4]);
+                break;
+                }
             ctlr->block = 0;
             ctlr->txsize = 0;
             ctlr->p_state = TD_BOOTSTRAP;
@@ -1043,7 +1047,7 @@ switch (opcode) {
         break;
 
     default:
-        //sim_printf("TU58: Unknown opcode %d\n", opcode);
+        sim_debug (TDDEB_TRC, ctlr->dptr, "td_process_packet(%s) Unit=%d Unknown Opcode: %d\n", opcode_name, ctlr->ibuf[4], opcode);
         break;
     }
 }
diff --git a/PDP11/pdp11_td.h b/PDP11/pdp11_td.h
index f6450c59..cc0053c5 100644
--- a/PDP11/pdp11_td.h
+++ b/PDP11/pdp11_td.h
@@ -68,6 +68,7 @@ t_stat td_wr_o_buf (CTLR *ctlr, int32 data);
 #define TDDEB_INT       00100                           /* interrupts */
 #define TDDEB_PKT       00200                           /* packet */
 #define TDDEB_DAT       00400                           /* data */
+#define TDDEB_ERR       01000                           /* errors */
 
 static DEBTAB td_deb[] = {
     { "OPS", TDDEB_OPS, "transactions" },
@@ -81,6 +82,7 @@ static DEBTAB td_deb[] = {
     { "INT", TDDEB_INT, "interrupts" },
     { "TRC", TDDEB_TRC, "trace" },
     { "DAT", TDDEB_DAT, "data" },
+    { "ERR", TDDEB_ERR, "errors" },
     { NULL, 0 }
     };