diff --git a/I7000/i701_sys.c b/I7000/i701_sys.c
index 3d4acc0..28dceb2 100644
--- a/I7000/i701_sys.c
+++ b/I7000/i701_sys.c
@@ -446,7 +446,7 @@ parse_sym(CONST char *cptr, t_addr addr, UNIT * uptr, t_value * val, int32 sw)
         i = 0;
         while (*cptr != '\0' && i < 6) {
             d <<= 6;
-            if (sim_ascii_to_six[0177 & *cptr] != -1)
+            if (sim_ascii_to_six[0177 & *cptr] != (const char)-1)
                 d |= sim_ascii_to_six[0177 & *cptr];
             cptr++;
             i++;
diff --git a/I7000/i7070_sys.c b/I7000/i7070_sys.c
index 1908dfa..d485af3 100644
--- a/I7000/i7070_sys.c
+++ b/I7000/i7070_sys.c
@@ -1068,7 +1068,7 @@ parse_sym(CONST char *cptr, t_addr addr, UNIT * uptr, t_value * val, int32 sw)
         i = 0;
         while (*cptr != '\0' && i < 5) {
             d <<= 8;
-            if (sim_ascii_to_six[0177 & *cptr] != -1)
+            if (sim_ascii_to_six[0177 & *cptr] != (const char)-1)
                 d |= bcd_mem[(int)sim_ascii_to_six[0177 & *cptr]];
             cptr++;
             i++;
diff --git a/I7000/i7080_chan.c b/I7000/i7080_chan.c
index 7150454..e60baff 100644
--- a/I7000/i7080_chan.c
+++ b/I7000/i7080_chan.c
@@ -57,7 +57,7 @@ extern uint16       iotraps;
 extern uint8        iocheck;
 extern UNIT         cpu_unit;
 extern uint16       IC;
-extern uint8        AC[5 * 512];
+extern uint8        AC[6 * 512];
 extern int          chwait;
 extern uint16       selreg;
 extern uint16       selreg2;
diff --git a/I7000/i7090_chan.c b/I7000/i7090_chan.c
index 1bbef90..b810b6c 100644
--- a/I7000/i7090_chan.c
+++ b/I7000/i7090_chan.c
@@ -55,7 +55,7 @@ extern UNIT         cpu_unit;
 extern uint16       IC;
 extern t_uint64     MQ;
 extern uint32       drum_addr;
-extern uint32       hsdrm_addr;
+extern t_uint64     hsdrm_addr;
 
 t_stat              chan_reset(DEVICE * dptr);
 void                chan_fetch(int chan);
@@ -356,10 +356,10 @@ chan_proc()
             /* On first command, copy it to drum address and load another */
             if ((chan_info[chan] & (CHAINF_RUN | CHAINF_START)) ==
                 CHAINF_START) {
-                hsdrm_addr = (int)M[location[chan] - 1];
+                hsdrm_addr = M[location[chan] - 1];
                 chan_info[chan] |= CHAINF_RUN;
                 if (chan_dev.dctrl & cmask)
-                    sim_debug(DEBUG_DETAIL, &chan_dev, "chan %d HDaddr %06o\n",
+                    sim_debug(DEBUG_DETAIL, &chan_dev, "chan %d HDaddr %012llo\n",
                               chan, hsdrm_addr);
                 chan_fetch(chan);
                 continue;
diff --git a/I7000/i7090_sys.c b/I7000/i7090_sys.c
index 67f0940..76b8207 100644
--- a/I7000/i7090_sys.c
+++ b/I7000/i7090_sys.c
@@ -1025,7 +1025,7 @@ parse_sym(CONST char *cptr, t_addr addr, UNIT * uptr, t_value * val, int32 sw)
         i = 0;
         while (*cptr != '\0' && i < 6) {
             d <<= 6;
-            if (ascii_to_mem[0177 & *cptr] != -1)
+            if (ascii_to_mem[0177 & *cptr] != (const char)-1)
                 d |= ascii_to_mem[0177 & *cptr];
             cptr++;
             i++;