diff --git a/NOVA/nova_cpu.c b/NOVA/nova_cpu.c
index ab2fc108..efd30f62 100644
--- a/NOVA/nova_cpu.c
+++ b/NOVA/nova_cpu.c
@@ -1244,7 +1244,7 @@ static const int32 boot_rom[] = {
 
 t_stat cpu_boot (int32 unitno, DEVICE *dptr)
 {
-int32    i;
+size_t i;
 
 for (i = 0; i < BOOT_LEN; i++) M[BOOT_START + i] = boot_rom[i];
 saved_PC = BOOT_START;
diff --git a/NOVA/nova_dkp.c b/NOVA/nova_dkp.c
index f5126f28..cc1f1ead 100644
--- a/NOVA/nova_dkp.c
+++ b/NOVA/nova_dkp.c
@@ -1085,7 +1085,7 @@ static const int32 boot_rom[] = {
 
 t_stat dkp_boot (int32 unitno, DEVICE *dptr)
 {
-int32   i;
+size_t i;
 
 for (i = 0; i < BOOT_LEN; i++)
     M[BOOT_START + i] = (uint16) boot_rom[i];
diff --git a/NOVA/nova_dsk.c b/NOVA/nova_dsk.c
index b1cfff3e..1c204bb7 100644
--- a/NOVA/nova_dsk.c
+++ b/NOVA/nova_dsk.c
@@ -297,7 +297,7 @@ static const int32 boot_rom[] = {
 
 t_stat dsk_boot (int32 unitno, DEVICE *dptr)
 {
-int32   i;
+size_t i;
 
 for (i = 0; i < BOOT_LEN; i++) M[BOOT_START + i] = (uint16) boot_rom[i];
 saved_PC = BOOT_START;
diff --git a/PDP8/pdp8_ct.c b/PDP8/pdp8_ct.c
index 45289576..735da73b 100644
--- a/PDP8/pdp8_ct.c
+++ b/PDP8/pdp8_ct.c
@@ -717,7 +717,7 @@ static const uint16 boot_rom[] = {
 
 t_stat ct_boot (int32 unitno, DEVICE *dptr)
 {
-int32 i;
+size_t i;
 extern int32 saved_PC;
 extern uint16 M[];
 
diff --git a/VAX/vax860_stddev.c b/VAX/vax860_stddev.c
index 45adc1f9..36480259 100644
--- a/VAX/vax860_stddev.c
+++ b/VAX/vax860_stddev.c
@@ -1019,6 +1019,8 @@ switch (rlcs_state) {
                 if (sim_fseek (uptr->fileref, da, SEEK_SET))
                     return SCPE_IOERR;
                 bcnt = sim_fread (rlcs_buf, sizeof (int16), RL_NUMBY, uptr->fileref);
+                if (bcnt != (sizeof (int16) * RL_NUMBY))
+                    return SCPE_IOERR;
                 }
             if (rlcs_bcnt < RL_NUMBY) {                 /* more data in buffer? */
                 cso_buf = rlcs_buf[rlcs_bcnt++];        /* return next word */
@@ -1048,6 +1050,8 @@ switch (rlcs_state) {
             if (sim_fseek (uptr->fileref, da, SEEK_SET))
                 return SCPE_IOERR;
             bcnt = sim_fwrite (rlcs_buf, sizeof (int16), RL_NUMBY, uptr->fileref);
+            if (bcnt != (sizeof (int16) * RL_NUMBY))
+                return SCPE_IOERR;
             rlcs_state = RL_IDLE;                       /* now idle */
             rlcs_bcnt = 0;
             cso_csr = cso_csr | CSR_DONE |              /* complete */
diff --git a/swtp6800/common/dc-4.c b/swtp6800/common/dc-4.c
index b4aff57d..038a2e96 100644
--- a/swtp6800/common/dc-4.c
+++ b/swtp6800/common/dc-4.c
@@ -502,8 +502,7 @@ int32 fdctrk(int32 io, int32 data)
         dsk_unit[cur_dsk].u4 = data & 0xFF;
         if (dsk_dev.dctrl & DEBUG_read)
             printf("\nfdctrk: Drive %d track set to %d", cur_dsk, dsk_unit[cur_dsk].u4);
-    } else
-        ;
+    }
     if (dsk_dev.dctrl & DEBUG_write)
         printf("\nfdctrk: Drive %d track read as %d", cur_dsk, dsk_unit[cur_dsk].u4);
     return dsk_unit[cur_dsk].u4;
@@ -519,8 +518,7 @@ int32 fdcsec(int32 io, int32 data)
             dsk_unit[cur_dsk].u5 = 1;
         if (dsk_dev.dctrl & DEBUG_write)
             printf("\nfdcsec: Drive %d sector set to %d", cur_dsk, dsk_unit[cur_dsk].u5);
-    } else
-            ;
+    }
     if (dsk_dev.dctrl & DEBUG_read)
         printf("\nfdcsec: Drive %d sector read as %d", cur_dsk, dsk_unit[cur_dsk].u5);
     return dsk_unit[cur_dsk].u5;