From 4ff1e317ac5100eb70380a3a49000747574d4ae6 Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Wed, 6 Jan 2016 08:09:50 -0800
Subject: [PATCH] PDP11: Fix DLI(DL11) and TDC(TU58) devices to be limited to a
 total of 16 devices between them

---
 PDP11/pdp11_dl.c | 27 ++++++++++++++++++++++++---
 PDP11/pdp11_td.c | 28 +++++++++++++++++++++++++++-
 2 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/PDP11/pdp11_dl.c b/PDP11/pdp11_dl.c
index 7398d0b0..e65300a9 100644
--- a/PDP11/pdp11_dl.c
+++ b/PDP11/pdp11_dl.c
@@ -591,6 +591,18 @@ sim_cancel (uptr);                                      /* stop poll */
 return r;
 }
 
+/* Number of DL devices used by TU58 */
+
+t_value dlx_tu58_count (void)
+{
+DEVICE *td_dptr = find_dev ("TDC");
+
+if ((td_dptr == NULL) ||
+    (td_dptr->flags & DEV_DIS))
+    return 0;
+return (t_value)((DIB *)td_dptr->ctxt)->numc;
+}
+
 /* Enable/disable device */
 
 void dlx_enbdis (int32 dis)
@@ -600,8 +612,17 @@ if (dis) {
     dlo_dev.flags = dlo_dev.flags | DEV_DIS;
     }
 else {
-    dli_dev.flags = dli_dev.flags & ~DEV_DIS;
-    dlo_dev.flags = dlo_dev.flags & ~DEV_DIS;
+    if (((dli_dev.flags & DEV_DIS) || (dlo_dev.flags & DEV_DIS)) && 
+        (dlx_tu58_count() < 16)) {
+        if ((dlx_desc.lines + dlx_tu58_count()) > 16)
+            dlx_desc.lines = 16 - dlx_tu58_count();
+        dli_dev.flags = dli_dev.flags & ~DEV_DIS;
+        dlo_dev.flags = dlo_dev.flags & ~DEV_DIS;
+        }
+    else {
+        dli_dev.flags = dli_dev.flags | DEV_DIS;
+        dlo_dev.flags = dlo_dev.flags | DEV_DIS;
+        }
     }
 return;
 }
@@ -615,7 +636,7 @@ t_stat r;
 
 if (cptr == NULL)
     return SCPE_ARG;
-newln = get_uint (cptr, 10, DLX_LINES, &r);
+newln = get_uint (cptr, 10, DLX_LINES - dlx_tu58_count(), &r);
 if ((r != SCPE_OK) || (newln == dlx_desc.lines))
     return r;
 if (newln == 0)
diff --git a/PDP11/pdp11_td.c b/PDP11/pdp11_td.c
index bd00bfc5..867750b9 100644
--- a/PDP11/pdp11_td.c
+++ b/PDP11/pdp11_td.c
@@ -1358,6 +1358,21 @@ static t_stat td_reset (DEVICE *dptr)
 {
 CTLR *ctlr;
 int ctl;
+static t_bool td_enabled_reset = FALSE;
+
+if (dptr->flags & DEV_DIS)
+    td_enabled_reset = FALSE;
+else {
+    /* When the TDC device is just being enabled, */
+    if (!td_enabled_reset) {
+        char num[16];
+
+        td_enabled_reset = TRUE;
+        /* make sure to bound the number of DLI devices */
+        sprintf (num, "%d", td_ctrls);
+        td_set_ctrls (dptr->units, 0, num, NULL);
+        }
+    }
 
 sim_debug (TDDEB_INT, dptr, "td_reset()\n");
 for (ctl=0; ctl<TD_NUMCTLR; ctl++) {
@@ -1396,11 +1411,12 @@ static t_stat td_set_ctrls (UNIT *uptr, int32 val, char *cptr, void *desc)
 {
 int32 newln, i;
 t_stat r;
+DEVICE *dli_dptr = find_dev ("DLI");
 
 if (cptr == NULL)
     return SCPE_ARG;
 newln = (int32)get_uint (cptr, 10, TD_NUMCTLR, &r);
-if ((r != SCPE_OK) || (newln == td_ctrls))
+if (r != SCPE_OK)
     return r;
 if (newln == 0)
     return SCPE_ARG;
@@ -1412,6 +1428,16 @@ if (newln < td_ctrls) {
     }
 td_ctrls = newln;
 td_dib.lnt = td_ctrls * td_dib.ulnt;            /* upd IO page lnt */
+/* Make sure that the number of TU58 controllers plus DL devices is 16 or less */
+if ((dli_dptr != NULL) && !(dli_dptr->flags & DEV_DIS) && 
+    ((((DIB *)dli_dptr->ctxt)->numc + td_ctrls) > 16)) {
+    dli_dptr->flags |= DEV_DIS;
+    dli_dptr->reset (dli_dptr);
+    if (td_ctrls < 16) {
+        dli_dptr->flags &= ~DEV_DIS;
+        dli_dptr->reset (dli_dptr);
+        }
+    }
 return td_reset (&tdc_dev);
 }