diff --git a/IBM360/ibm360_cdp.c b/IBM360/ibm360_cdp.c
index 9a34821..7d1cec3 100644
--- a/IBM360/ibm360_cdp.c
+++ b/IBM360/ibm360_cdp.c
@@ -115,7 +115,6 @@ DEVICE              cdp_dev = {
 uint8  cdp_startcmd(UNIT *uptr, uint16 chan,  uint8 cmd) {
     DEVICE         *dptr = find_dev_from_unit(uptr);
     int            unit = (uptr - dptr->units);
-    uint8   ch;
 
     if ((uptr->u3 & (CDP_CARD|CDP_CMDMSK)) != 0) {
         if ((uptr->flags & UNIT_ATT) != 0)
diff --git a/IBM360/ibm360_cdr.c b/IBM360/ibm360_cdr.c
index 0210c5d..15833cc 100644
--- a/IBM360/ibm360_cdr.c
+++ b/IBM360/ibm360_cdr.c
@@ -110,7 +110,6 @@ DEVICE              cdr_dev = {
 uint8  cdr_startcmd(UNIT *uptr, uint16 chan,  uint8 cmd) {
     DEVICE         *dptr = find_dev_from_unit(uptr);
     int            unit = (uptr - dptr->units);
-    uint8          ch;
 
     if ((uptr->u3 & CDR_CMDMSK) != 0) {
         if ((uptr->flags & UNIT_ATT) != 0)
@@ -249,7 +248,6 @@ t_stat
 cdr_boot(int32 unit_num, DEVICE * dptr)
 {
     UNIT               *uptr = &dptr->units[unit_num];
-    t_stat              r;
 
     if ((uptr->flags & UNIT_ATT) == 0)
        return SCPE_UNATT;       /* attached? */
diff --git a/IBM360/ibm360_chan.c b/IBM360/ibm360_chan.c
index 5ade848..10461e0 100644
--- a/IBM360/ibm360_chan.c
+++ b/IBM360/ibm360_chan.c
@@ -401,7 +401,6 @@ int
 chan_read_byte(uint16 addr, uint8 *data) {
     int         chan = find_subchan(addr);
     int         byte;
-    int         k;
 
     /* Abort if we have any errors */
     if (chan < 0)
@@ -449,9 +448,7 @@ chan_read_byte(uint16 addr, uint8 *data) {
 int
 chan_write_byte(uint16 addr, uint8 *data) {
     int          chan = find_subchan(addr);
-    int          byte;
     int          offset;
-    int          k;
     uint32       mask;
 
     /* Abort if we have any errors */
@@ -636,7 +633,6 @@ startio(uint16 addr) {
     int          chan = find_subchan(addr);
     DIB         *dibp = dev_unit[addr];
     UNIT        *uptr;
-    uint8        status;
 
     /* Find channel this device is on, if no none return cc=3 */
     if (chan < 0 || dibp == 0) {
@@ -829,7 +825,6 @@ int haltio(uint16 addr) {
     int           chan = find_subchan(addr);
     DIB          *dibp = dev_unit[addr];
     UNIT         *uptr;
-    uint8         status;
 
     /* Find channel this device is on, if no none return cc=3 */
     if (chan < 0 || dibp == 0) {
@@ -884,7 +879,6 @@ t_stat chan_boot(uint16 addr, DEVICE *dptyr) {
     int          chan = find_subchan(addr);
     DIB         *dibp = dev_unit[addr];
     UNIT        *uptr;
-    uint8        status;
     int          i;
 
     if (chan < 0 || dibp == 0)
@@ -956,7 +950,7 @@ scan_chan(uint16 mask, int irq_en) {
                 sim_debug(DEBUG_EXP, &cpu_dev, "Scan(%x %x %x %x) end\n", i,
                          chan_status[i], imask, mask);
                 if ((chan_status[i] & STATUS_DEND) != 0 &&
-                     (imask & mask) != 0 || loading != 0) {
+                     ((imask & mask) != 0 || loading != 0)) {
                     pend = chan_dev[i];
                     break;
                 }
@@ -1009,7 +1003,7 @@ scan_chan(uint16 mask, int irq_en) {
 t_stat
 chan_set_devs()
 {
-    int                 i, j;
+    uint32              i, j;
 
     for(i = 0; i < MAX_DEV; i++) {
         dev_unit[i] = NULL;                  /* Device pointer */
@@ -1020,7 +1014,6 @@ chan_set_devs()
         UNIT               *uptr = dptr->units;
         DIB                *dibp = (DIB *) dptr->ctxt;
         int                 addr;
-        int                 chan;
 
         /* If no DIB, not channel device */
         if (dibp == NULL)
@@ -1050,8 +1043,6 @@ set_dev_addr(UNIT * uptr, int32 val, CONST char *cptr, void *desc)
     DIB                *dibp;
     t_value             newdev;
     t_stat              r;
-    int                 num;
-    int                 type;
     int                 i;
     int                 devaddr;
 
@@ -1072,7 +1063,7 @@ set_dev_addr(UNIT * uptr, int32 val, CONST char *cptr, void *desc)
     if (r != SCPE_OK)
         return r;
 
-    if ((newdev >> 8) > channels)
+    if ((newdev >> 8) > (t_value)channels)
         return SCPE_ARG;
 
     if (newdev >= MAX_DEV)
@@ -1127,7 +1118,6 @@ t_stat
 show_dev_addr(FILE * st, UNIT * uptr, int32 v, CONST void *desc)
 {
     DEVICE             *dptr;
-    DIB                *dibp;
     int                 addr;
 
 
diff --git a/IBM360/ibm360_com.c b/IBM360/ibm360_com.c
index 9b8e235..e999a20 100644
--- a/IBM360/ibm360_com.c
+++ b/IBM360/ibm360_com.c
@@ -238,7 +238,6 @@ uint8  coml_startcmd(UNIT *uptr, uint16 chan,  uint8 cmd) {
     uint16         addr = GET_UADDR(uptr->u3);
     DEVICE         *dptr = find_dev_from_unit(uptr);
     int            unit = (uptr - dptr->units);
-    uint8          ch;
 
     sim_debug(DEBUG_CMD, dptr, "CMD unit=%d %x\n", unit, cmd);
     if ((uptr->u3 & 0xff) != 0) {
@@ -274,7 +273,6 @@ uint8  coml_haltio(UNIT *uptr) {
     DEVICE         *dptr = find_dev_from_unit(uptr);
     int            unit = (uptr - dptr->units);
     int            cmd = uptr->u3 & 0xff;
-    uint8          ch;
 
     sim_debug(DEBUG_CMD, dptr, "HLTIO unit=%d %x\n", unit, cmd);
 
@@ -476,7 +474,6 @@ com_reset(DEVICE * dptr)
 void
 coml_ini(UNIT * uptr, t_bool f)
 {
-    UNIT          *srv;
 }
 
 t_stat
@@ -502,7 +499,6 @@ com_detach(UNIT * uptr)
 {
     t_stat        r;
     int           i;
-    UNIT          *srv;
 
     for (i = 0; i< com_desc.lines; i++) {
         (void)tmxr_set_get_modem_bits(&com_ldsc[i], 0, TMXR_MDM_DTR, NULL);
@@ -517,7 +513,6 @@ com_detach(UNIT * uptr)
 t_stat com_help (FILE *st, DEVICE *dptr, UNIT *uptr, int32 flag,
     const char *cptr)
 {
-      int i;
 fprint_set_help (st, dptr);
 fprint_show_help (st, dptr);
 return SCPE_OK;
diff --git a/IBM360/ibm360_cpu.c b/IBM360/ibm360_cpu.c
index f473106..152469a 100644
--- a/IBM360/ibm360_cpu.c
+++ b/IBM360/ibm360_cpu.c
@@ -142,6 +142,7 @@ uint32       tlb[256];             /* Translation look aside buffer */
 #define B1(x)   (((x) >> 12) & 0xf)
 #define D1(x)   ((x) & 0xfff)
 #define X2(x)   R2(x)
+#define NEG(x)  (uint32)(-(int32)(x))
 
 #define PTE_LEN     0xff000000     /* Page table length */
 #define PTE_ADR     0x00fffffe     /* Address of table */
@@ -681,7 +682,6 @@ int WriteHalf(uint32 addr, uint32 data) {
      uint32     pa;
      uint32     pa2;
      int        offset;
-     int        o;
 
      /* Validate address */
      if (TransAddr(addr, &pa))
@@ -774,7 +774,7 @@ sim_instr(void)
     uint8           zone;
     uint16          irq;
     int             e1, e2;
-    int             temp, temp2;
+    int             temp;
 #ifdef USE_64BIT
     t_uint64        src1L;
     t_uint64        src2L;
@@ -1080,9 +1080,7 @@ opr:
                 } else if (addr1 >= MEMSIZE) {
                     storepsw(OPPSW, IRC_ADDR);
                 } else if (cpu_unit[0].flags & FEAT_PROT) {
-                    if (TransAddr(addr1, &addr2))
-                        break;
-                    key[addr2 >> 11] = src1 & 0xf8;
+                    key[addr1 >> 11] = src1 & 0xf8;
                 }
                 break;
 
@@ -1097,10 +1095,8 @@ opr:
                 } else if (addr1 >= MEMSIZE) {
                     storepsw(OPPSW, IRC_ADDR);
                 } else {
-                    if (TransAddr(addr1, &addr2))
-                        break;
                     dest &= 0xffffff00;
-                    dest |= key[addr2 >> 11];
+                    dest |= key[addr1 >> 11] & 0xf8;
                     regs[reg1] = dest;
                 }
                 break;
@@ -1197,7 +1193,7 @@ opr:
         case OP_LCR:
                 if (dest == MSIGN)
                    goto set_cc3;
-                dest = -dest;
+                dest = NEG(dest);
                 /* Fall through */
 
         case OP_LTR:
@@ -1208,7 +1204,7 @@ set_cc:
 
         case OP_LNR:
                 if ((dest & MSIGN) == 0)
-                   dest = -dest;
+                   dest = NEG(dest);
                 goto set_cc;
 
         case OP_LA:
@@ -1233,7 +1229,7 @@ set_cc:
         case OP_S:
         case OP_SR:
         case OP_SH:
-                src2 = -src2;
+                src2 = NEG(src2);
                 /* Fall through */
 
         case OP_A:
@@ -1253,7 +1249,7 @@ set_cc3:
 
         case OP_SL:
         case OP_SLR:
-                src2 = -src2;
+                src2 = NEG(src2);
                 /* Fall through */
 
         case OP_AL:
@@ -1289,16 +1285,16 @@ set_cc3:
 
                 if (src1 & MSIGN) {
                     fill = 1;
-                    src1 = -src1;
+                    src1 = NEG(src1);
                 }
                 if (src2 & MSIGN) {
                     fill ^= 1;
-                    src2 = -src2;
+                    src2 = NEG(src2);
                 }
 #ifdef USE_64BIT
                 src1L = ((t_uint64)src1) * ((t_uint64)src2);
                 if (fill)
-                    src1L = -src1L;
+                    src1L = NEG(src1L);
                 if (op != OP_MH) {
                     STDBL(reg1, src1L);
                 } else {
@@ -1348,11 +1344,11 @@ set_cc3:
 
                 if (src1L & MSIGNL) {
                     fill = 3;
-                    src1L = -src1L;
+                    src1L = NEG(src1L);
                 }
                 if (src2 & MSIGN) {
                     fill ^= 1;
-                    src2 = -src2;
+                    src2 = NEG(src2);
                 }
                 src2L = src1L % (t_uint64)src2;
                 src1L = src1L / (t_uint64)src2;
@@ -1377,7 +1373,7 @@ set_cc3:
                 }
                 if (src2 & MSIGN) {
                     fill ^= 1;
-                    src2 = -src2;
+                    src2 = NEG(src2);
                 }
                 dest = 0;
                 for (reg = 0; reg < 32; reg++) {
@@ -1405,9 +1401,9 @@ set_cc3:
                 }
 #endif
                 if (fill & 1)
-                    dest = -dest;
+                    dest = NEG(dest);
                 if (fill & 2)
-                    src1 = -src1;
+                    src1 = NEG(src1);
                 regs[reg1] = src1;
                 regs[reg1|1] = dest;
                 break;
@@ -1817,9 +1813,6 @@ save_dbl:
                 } else if (flags & PROBLEM) {
                     storepsw(OPPSW, IRC_PRIV);
                 } else {
-                    uint32  seg;
-                    uint32  page;
-
                     /* RX in RS range */
                     if (X2(reg) != 0)
                         addr1 = (addr1 + regs[X2(reg)]) & AMASK;
@@ -2096,7 +2089,7 @@ save_dbl:
                 }
                 /* Twos compliment if needed */
                 if (fill == 0xB || fill == 0xD)
-                    dest = -dest;
+                    dest = NEG(dest);
                 regs[reg1] = dest;
                 break;
 
@@ -2106,7 +2099,7 @@ save_dbl:
                 src1 = 0;
                 src1h = 0;
                 if (dest & MSIGN) {  /* Save sign */
-                    dest = -dest;
+                    dest = NEG(dest);
                     fill = 1;
                 } else
                     fill = 0;
@@ -4476,7 +4469,8 @@ dec_div(int op, uint32 addr1, uint8 len1, uint32 addr2, uint8 len2)
 
 t_stat cpu_reset (DEVICE *dptr)
 {
-    st_key = cc = pmsk = irqcode = flags = irqaddr = loading = 0;
+    st_key = cc = pmsk = flags = 0;
+    irqcode = irqaddr = loading = 0;
     dat_en = irq_en = ext_en = 0;
     chan_set_devs();
     if (M == NULL) {                        /* first time init? */
@@ -4572,7 +4566,7 @@ if ((mc != 0) && !get_yn ("Really truncate memory [N]?", FALSE))
 nM = (uint32 *) calloc (val >> 2, sizeof (uint32));
 if (nM == NULL)
     return SCPE_MEM;
-clim = (val < MEMSIZE)? val >> 2: max;
+clim = ((t_addr)val < MEMSIZE)? val >> 2: max;
 for (i = 0; i < clim; i++)
     nM[i] = M[i];
 free (M);
@@ -4644,7 +4638,6 @@ cpu_show_hist(FILE * st, UNIT * uptr, int32 val, CONST void *desc)
     for (k = 0; k < lnt; k++) { /* print specified */
         h = &hst[(++di) % hst_lnt];     /* entry pointer */
         if (h->pc & HIST_PC) {   /* instruction? */
-            int i;
             fprintf(st, "%06x %06x %06x %08x %08x %08x %1x %04x ",
                        h->pc & PAMASK, h->addr1 & PAMASK, h->addr2 & PAMASK,
                        h->src1, h->src2, h->dest, h->cc, h->inst[0]);
@@ -4661,12 +4654,10 @@ cpu_show_hist(FILE * st, UNIT * uptr, int32 val, CONST void *desc)
             fputc('\n', st);    /* end line */
         }                       /* end else instruction */
         if (h->pc & HIST_LPW) {   /* load PSW */
-            int i;
-            fprintf(st, " LPSW  %06x     %08x %08x\n", h->pc & PAMASK, h->src1, h->src2);
+            fprintf(st," LPSW  %06x     %08x %08x\n", h->pc & PAMASK, h->src1, h->src2);
         }                       /* end else instruction */
         if (h->pc & HIST_SPW) {   /* load PSW */
-            int i;
-            fprintf(st, " SPSW  %06x     %08x %08x\n", h->pc & PAMASK,  h->src1, h->src2);
+            fprintf(st," SPSW  %06x     %08x %08x\n", h->pc & PAMASK,  h->src1, h->src2);
         }                       /* end else instruction */
     }                           /* end for */
     return SCPE_OK;
diff --git a/IBM360/ibm360_dasd.c b/IBM360/ibm360_dasd.c
index 68545c9..3c1043e 100644
--- a/IBM360/ibm360_dasd.c
+++ b/IBM360/ibm360_dasd.c
@@ -196,9 +196,9 @@ struct dasd_t
 struct disk_t
 {
     const char         *name;         /* Type Name */
-    unsigned int        cyl;          /* Number of cylinders */
-    unsigned int        heads;        /* Number of heads/cylinder */
-    unsigned int        bpt;          /* Max bytes per track */
+    int                 cyl;          /* Number of cylinders */
+    int                 heads;        /* Number of heads/cylinder */
+    int                 bpt;          /* Max bytes per track */
     uint8               sen_cnt;      /* Number of sense bytes */
     uint8               dev_type;     /* Device type code */
 }
@@ -454,7 +454,8 @@ void dasd_adjpos(UNIT * uptr)
 
     /* Set ourselves to start of track */
     data->state = DK_POS_HA;
-    data->rpos = data->rec = data->count = data->klen = data->dlen = 0;
+    data->rec = data->klen = 0;
+    data->rpos = data->count = data->dlen = 0;
     data->tstart = (uptr->u4 & 0xff) * data->tsize;
     rec = &data->cbuf[data->rpos + data->tstart];
     /* Skip forward until we reach pos */
@@ -1762,7 +1763,6 @@ dasd_boot(int32 unit_num, DEVICE * dptr)
 {
     UNIT               *uptr = &dptr->units[unit_num];
     struct dasd_t      *data = (struct dasd_t *)(uptr->up7);
-    t_stat              r;
 
     if ((uptr->flags & UNIT_ATT) == 0)
         return SCPE_UNATT;      /* attached? */
diff --git a/IBM360/ibm360_lpr.c b/IBM360/ibm360_lpr.c
index 01031c9..4108497 100644
--- a/IBM360/ibm360_lpr.c
+++ b/IBM360/ibm360_lpr.c
@@ -118,7 +118,7 @@ DEVICE              lpr_dev = {
 t_stat
 lpr_setlpp(UNIT *uptr, int32 val, CONST char *cptr, void *desc)
 {
-    int i;
+    t_addr i;
     if (cptr == NULL)
        return SCPE_ARG;
     if (uptr == NULL)
@@ -177,7 +177,7 @@ print_line(UNIT * uptr)
     uptr->pos += i;
     sim_debug(DEBUG_DETAIL, &lpr_dev, "%s", out);
     uptr->u4++;
-    if (uptr->u4 > uptr->capac) {
+    if ((t_addr)uptr->u4 > uptr->capac) {
        uptr->u4 = 1;
     }
 
@@ -187,8 +187,6 @@ print_line(UNIT * uptr)
 
 uint8 lpr_startcmd(UNIT * uptr, uint16 chan, uint8 cmd)
 {
-    uint8   ch;
-
     if ((uptr->u3 & LPR_CMDMSK) != 0) {
        if ((uptr->flags & UNIT_ATT) != 0)
             return SNS_BSY;
diff --git a/IBM360/ibm360_mt.c b/IBM360/ibm360_mt.c
index 56c1177..48a31c6 100644
--- a/IBM360/ibm360_mt.c
+++ b/IBM360/ibm360_mt.c
@@ -228,7 +228,6 @@ uint8  mt_startcmd(UNIT *uptr, uint16 chan,  uint8 cmd) {
     uint16         addr = GET_UADDR(uptr->u3);
     DEVICE         *dptr = find_dev_from_unit(uptr);
     int            unit = (uptr - dptr->units);
-    uint8          ch;
 
     if (mt_busy[GET_DEV_BUF(dptr->flags)] != 0 || (uptr->u3 & MT_CMDMSK) != 0) {
         sim_debug(DEBUG_CMD, dptr, "CMD busy unit=%d %x\n", unit, cmd);
@@ -451,7 +450,7 @@ t_stat mt_srv(UNIT * uptr)
              if (uptr->u3 & MT_CONV) {
                  sim_debug(DEBUG_DATA, dptr, "Read raw data unit=%d %d %02x %02x\n",
                        unit, uptr->u4, ch, uptr->u6);
-                 if (uptr->u6 == 0 && uptr->u4 < uptr->hwmark) {
+                 if (uptr->u6 == 0 && (t_addr)uptr->u4 < uptr->hwmark) {
                      uptr->u6 = MT_CONV1 | ch;
                      sim_activate(uptr, 20);
                      return SCPE_OK;
@@ -474,7 +473,7 @@ t_stat mt_srv(UNIT * uptr)
          if (chan_write_byte(addr, &ch)) {
              sim_debug(DEBUG_DATA, dptr, "Read unit=%d EOR\n\r", unit);
              /* If not read whole record, skip till end */
-             if (uptr->u4 < uptr->hwmark) {
+             if ((t_addr)uptr->u4 < uptr->hwmark) {
                  /* Send dummy character to force SLI */
                  chan_write_byte(addr, &ch);
                  sim_activate(uptr, (uptr->hwmark-uptr->u4) * 20);
@@ -487,7 +486,7 @@ t_stat mt_srv(UNIT * uptr)
          } else {
               sim_debug(DEBUG_DATA, dptr, "Read data unit=%d %d %02x\n\r",
                        unit, uptr->u4, ch);
-              if (uptr->u4 >= uptr->hwmark) {       /* In IRG */
+              if ((t_addr)uptr->u4 >= uptr->hwmark) {       /* In IRG */
                   /* Handle end of record */
                   uptr->u3 &= ~MT_CMDMSK;
                   mt_busy[bufnum] &= ~1;
@@ -591,7 +590,7 @@ t_stat mt_srv(UNIT * uptr)
              if (uptr->u3 & MT_TRANS)
                  ch = bcd_to_ebcdic[ch];
              if (uptr->u3 & MT_CONV) {
-                 if (uptr->u6 == 0 && uptr->u4 < uptr->hwmark) {
+                 if (uptr->u6 == 0 && (t_addr)uptr->u4 < uptr->hwmark) {
                      uptr->u6 = MT_CONV1 | ch;
                      sim_activate(uptr, 20);
                      return SCPE_OK;
@@ -907,7 +906,6 @@ t_stat
 mt_boot(int32 unit_num, DEVICE * dptr)
 {
     UNIT               *uptr = &dptr->units[unit_num];
-    t_stat              r;
 
     if ((uptr->flags & UNIT_ATT) == 0)
         return SCPE_UNATT;      /* attached? */
diff --git a/IBM360/ibm360_sys.c b/IBM360/ibm360_sys.c
index 2d50bfa..a9e80d9 100644
--- a/IBM360/ibm360_sys.c
+++ b/IBM360/ibm360_sys.c
@@ -372,8 +372,6 @@ t_opcode  optab[] = {
 
 void fprint_inst(FILE *of, uint16 *val) {
 uint8           inst = (val[0] >> 8) &  0xff;
-int             i;
-int             l = 1;
 t_opcode        *tab;
 
     for (tab = optab; tab->name != NULL; tab++) {