From edb8bbeceb75baf519be7bf6c97f6fc22a7af429 Mon Sep 17 00:00:00 2001
From: Richard Cornwell <rcornwell@github.com>
Date: Mon, 16 Mar 2020 19:43:45 -0400
Subject: [PATCH] KA10: Fixed some bugs in disabled devices.

---
 PDP10/kx10_rh.c | 17 ++++-------------
 PDP10/kx10_rp.c |  4 ++--
 PDP10/kx10_tu.c | 15 ++++++---------
 3 files changed, 12 insertions(+), 24 deletions(-)

diff --git a/PDP10/kx10_rh.c b/PDP10/kx10_rh.c
index 5751222..c2e5d72 100644
--- a/PDP10/kx10_rh.c
+++ b/PDP10/kx10_rh.c
@@ -243,10 +243,8 @@ t_stat rh_devio(uint32 dev, uint64 *data) {
               }
               if (rhc->reg < 040) {
                   int parity;
-                  if (rhc->dev_read(dptr, rhc, rhc->reg, &drdat)) {
-                      rhc->rae |= 1 << rhc->drive;
+                  if (rhc->dev_read(dptr, rhc, rhc->reg, &drdat))
                       rhc->status |= RH20_DR_RESP;
-                  }
                   *data = (uint64)(drdat & 0177777);
                   parity = (int)((*data >> 8) ^ *data);
                   parity = (parity >> 4) ^ parity;
@@ -290,10 +288,8 @@ t_stat rh_devio(uint32 dev, uint64 *data) {
                          set_interrupt(rhc->devnum, rhc->status);
                          return SCPE_OK;
                      }
-                     if (rhc->dev_write(dptr, rhc, rhc->reg & 037, (int)(*data & 0777777))) {
-                          rhc->rae |= 1 << rhc->drive;
+                     if (rhc->dev_write(dptr, rhc, rhc->reg & 037, (int)(*data & 0777777)))
                           rhc->status |= RH20_DR_RESP;
-                     }
                      if (((rhc->status & IADR_ATTN) != 0 && rhc->attn != 0)
                              || (rhc->status & PI_ENABLE))
                          set_interrupt(rhc->devnum, rhc->status);
@@ -390,10 +386,8 @@ t_stat rh_devio(uint32 dev, uint64 *data) {
             return SCPE_OK;
         }
         if (rhc->reg == 040) {
-              if (rhc->dev_read(dptr, rhc, 0, &drdat)) {
-                  rhc->rae |= (1 << rhc->drive);
+              if (rhc->dev_read(dptr, rhc, 0, &drdat))
                   rhc->status |= CR_DRE;
-              }
               *data = (uint64)(drdat & 077);
               *data |= ((uint64)(rhc->cia)) << 6;
               *data |= ((uint64)(rhc->xfer_drive)) << 18;
@@ -459,7 +453,6 @@ t_stat rh_devio(uint32 dev, uint64 *data) {
                 rh_setup(rhc, (uint32)(*data >> 6));
                 rhc->xfer_drive = (int)(*data >> 18) & 07;
                 if (rhc->dev_write(dptr, rhc, 0, (uint32)(*data & 077))) {
-                    rhc->rae |= 1 << rhc->drive;
                     rhc->status |= CR_DRE;
                 }
                 sim_debug(DEBUG_DATAIO, dptr,
@@ -482,10 +475,8 @@ t_stat rh_devio(uint32 dev, uint64 *data) {
                 if (rhc->rae & (1 << rhc->drive)) {
                     return SCPE_OK;
                 }
-                if (rhc->dev_write(dptr, rhc, rhc->reg & 037, (uint32)(*data & 0777777))) {
-                    rhc->rae |= 1 << rhc->drive;
+                if (rhc->dev_write(dptr, rhc, rhc->reg & 037, (uint32)(*data & 0777777)))
                     rhc->status |= CR_DRE;
-                }
              }
          }
          clr_interrupt(dev);
diff --git a/PDP10/kx10_rp.c b/PDP10/kx10_rp.c
index 2232419..a7040d9 100644
--- a/PDP10/kx10_rp.c
+++ b/PDP10/kx10_rp.c
@@ -497,7 +497,7 @@ rp_write(DEVICE *dptr, struct rh_if *rhc, int reg, uint32 data) {
     UNIT          *uptr = &dptr->units[unit];
     int            dtype = GET_DTYPE(uptr->flags);
 
-    if ((uptr->flags & UNIT_DIS) != 0)
+    if ((uptr->flags & UNIT_DIS) != 0 && reg != 04)
         return 1;
     if ((uptr->CMD & CS1_GO) && reg != 04) {
         uptr->CMD |= (ER1_RMR << 16)|DS_ERR;
@@ -661,7 +661,7 @@ rp_read(DEVICE *dptr, struct rh_if *rhc, int reg, uint32 *data) {
     uint32        temp = 0;
     int           i;
 
-    if ((uptr->flags & UNIT_DIS) != 0)
+    if ((uptr->flags & UNIT_DIS) != 0 && reg != 04)
         return 1;
     if ((uptr->flags & UNIT_ATT) == 0 && reg != 04) {    /* not attached? */
         *data = 0;
diff --git a/PDP10/kx10_tu.c b/PDP10/kx10_tu.c
index 3886bad..34370f3 100644
--- a/PDP10/kx10_tu.c
+++ b/PDP10/kx10_tu.c
@@ -254,7 +254,7 @@ tu_write(DEVICE *dptr, struct rh_if *rhc, int reg, uint32 data) {
     UNIT          *uptr = &dptr->units[unit];
     int            i;
 
-    if (rhc->drive != 0)   /* Only one unit at 0 */
+    if (rhc->drive != 0 && reg != 04)   /* Only one unit at 0 */
        return 1;
 
     if (uptr->CMD & CS1_GO) {
@@ -334,11 +334,9 @@ tu_write(DEVICE *dptr, struct rh_if *rhc, int reg, uint32 data) {
         break;
     case  004:  /* atten summary */
         rhc->attn = 0;
-        for (i = 0; i < 8; i++) {
-            if (data & (1<<i))
+        if (data & 1) {
+            for (i = 0; i < 8; i++)
                 dptr->units[i].CMD &= ~CS_ATA;
-            if (dptr->units[i].CMD & CS_ATA)
-               rhc->attn = 1;
         }
         break;
     case  005:  /* frame count */
@@ -367,7 +365,7 @@ tu_read(DEVICE *dptr, struct rh_if *rhc, int reg, uint32 *data) {
     uint32         temp = 0;
     int            i;
 
-    if (rhc->drive != 0)   /* Only one unit at 0 */
+    if (rhc->drive != 0 && reg != 4)   /* Only one unit at 0 */
        return 1;
 
     switch(reg) {
@@ -408,9 +406,8 @@ tu_read(DEVICE *dptr, struct rh_if *rhc, int reg, uint32 *data) {
         break;
     case  004:  /* atten summary */
         for (i = 0; i < 8; i++) {
-            if (dptr->units[i].CMD & CS_ATA) {
-                temp |= 1 << i;
-            }
+            if (dptr->units[i].CMD & CS_ATA)
+                temp |= 1;
         }
         break;
     case  005:  /* frame count */