From 253f8a8dcf758dfa47cc67b231a4169b82aa9b43 Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Mon, 29 Feb 2016 16:37:18 -0800
Subject: [PATCH] VAX: Move CPU register and routine declarations into
 vax_defs.h

Avoid redundant declarations in every simulator module that uses them
and allow compiler to validate consistency of declarations and definitions.
---
 VAX/vax610_defs.h    |   1 +
 VAX/vax610_io.c      |   4 --
 VAX/vax610_mem.c     |   2 -
 VAX/vax610_stddev.c  |   5 --
 VAX/vax610_sysdev.c  |  10 ----
 VAX/vax610_syslist.c |   3 --
 VAX/vax630_defs.h    |   1 +
 VAX/vax630_io.c      |   6 ---
 VAX/vax630_stddev.c  |   3 --
 VAX/vax630_sysdev.c  |  17 -------
 VAX/vax630_syslist.c |   4 --
 VAX/vax730_defs.h    |   1 +
 VAX/vax730_mem.c     |   2 -
 VAX/vax730_rb.c      |   2 -
 VAX/vax730_stddev.c  |   2 -
 VAX/vax730_sys.c     |  11 -----
 VAX/vax730_syslist.c |   3 --
 VAX/vax730_uba.c     |   4 --
 VAX/vax750_cmi.c     |  11 -----
 VAX/vax750_defs.h    |   1 +
 VAX/vax750_mem.c     |   2 -
 VAX/vax750_stddev.c  |   2 -
 VAX/vax750_syslist.c |   4 --
 VAX/vax750_uba.c     |   6 ---
 VAX/vax780_defs.h    |   1 +
 VAX/vax780_fload.c   |   1 -
 VAX/vax780_mem.c     |   2 -
 VAX/vax780_sbi.c     |  11 -----
 VAX/vax780_stddev.c  |   2 -
 VAX/vax780_syslist.c |   4 --
 VAX/vax780_uba.c     |   3 --
 VAX/vax7x0_mba.c     |   1 -
 VAX/vax860_abus.c    |  13 -----
 VAX/vax860_defs.h    |   1 +
 VAX/vax860_sbia.c    |  11 -----
 VAX/vax860_stddev.c  |   4 --
 VAX/vax860_syslist.c |   3 --
 VAX/vax_cis.c        |  17 -------
 VAX/vax_cmode.c      |  14 ------
 VAX/vax_cpu.c        |  76 +-----------------------------
 VAX/vax_cpu1.c       |  67 ++++++++++----------------
 VAX/vax_defs.h       | 110 +++++++++++++++++++++++++++++++++++++++++++
 VAX/vax_fpa.c        |   5 --
 VAX/vax_io.c         |   5 --
 VAX/vax_mmu.c        |  15 +-----
 VAX/vax_mmu.h        |   7 ++-
 VAX/vax_octa.c       |  10 ----
 VAX/vax_stddev.c     |   3 --
 VAX/vax_sys.c        |   3 --
 VAX/vax_syscm.c      |   1 -
 VAX/vax_sysdev.c     |  15 ------
 VAX/vax_syslist.c    |   2 -
 VAX/vax_vc.c         |   4 --
 VAX/vaxmod_defs.h    |   1 +
 54 files changed, 149 insertions(+), 370 deletions(-)

diff --git a/VAX/vax610_defs.h b/VAX/vax610_defs.h
index 2e7cdaa0..ca5c3a2d 100644
--- a/VAX/vax610_defs.h
+++ b/VAX/vax610_defs.h
@@ -325,6 +325,7 @@ typedef struct {
 #define SET_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] | (INT_##dv)
 #define CLR_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] & ~(INT_##dv)
 #define IORETURN(f,v)   ((f)? (v): SCPE_OK)             /* cond error return */
+extern int32 int_req[IPL_HLVL];                         /* intr, IPL 14-17 */
 
 /* Logging */
 
diff --git a/VAX/vax610_io.c b/VAX/vax610_io.c
index eee4994c..7fe6a51b 100644
--- a/VAX/vax610_io.c
+++ b/VAX/vax610_io.c
@@ -35,10 +35,6 @@ int32 int_req[IPL_HLVL] = { 0 };                        /* intr, IPL 14-17 */
 int32 int_vec_set[IPL_HLVL][32] = { 0 };                /* bits to set in vector */
 int32 autcon_enb = 1;                                   /* autoconfig enable */
 
-extern int32 PSL, SISR, trpirq, mem_err, hlt_pin;
-extern int32 p1;
-extern jmp_buf save_env;
-
 int32 eval_int (void);
 t_stat qba_reset (DEVICE *dptr);
 const char *qba_description (DEVICE *dptr);
diff --git a/VAX/vax610_mem.c b/VAX/vax610_mem.c
index 7b10b472..597cee2d 100644
--- a/VAX/vax610_mem.c
+++ b/VAX/vax610_mem.c
@@ -35,8 +35,6 @@
 #define MCSR_ECR        0x4000                          /* extended CSR read enable */
 #define MCSR_RW         (MCSR_ECR|MCSR_WWP|MCSR_PEN)
 
-extern UNIT cpu_unit;
-
 int32 mctl_csr[MAX_MCTL_COUNT];
 int32 mctl_count = 0;
 
diff --git a/VAX/vax610_stddev.c b/VAX/vax610_stddev.c
index a89c7492..c0e92234 100644
--- a/VAX/vax610_stddev.c
+++ b/VAX/vax610_stddev.c
@@ -68,11 +68,6 @@
 #define CLK_DELAY       5000                            /* 100 Hz */
 #define TMXR_MULT       1                               /* 100 Hz */
 
-extern int32 int_req[IPL_HLVL];
-extern int32 hlt_pin;
-extern jmp_buf save_env;
-extern int32 p1;
-
 int32 tti_csr = 0;                                      /* control/status */
 uint32 tti_buftime;                                     /* time input character arrived */
 int32 tto_csr = 0;                                      /* control/status */
diff --git a/VAX/vax610_sysdev.c b/VAX/vax610_sysdev.c
index afbc643f..1887636b 100644
--- a/VAX/vax610_sysdev.c
+++ b/VAX/vax610_sysdev.c
@@ -48,13 +48,6 @@ struct boot_dev {
     int32               code;
     };
 
-extern int32 R[16];
-extern int32 in_ie;
-extern int32 mchk_va, mchk_ref;
-extern int32 int_req[IPL_HLVL];
-extern jmp_buf save_env;
-extern int32 p1;
-extern int32 trpirq, mem_err;
 extern DEVICE vc_dev, lk_dev, vs_dev;
 
 int32 conisp, conpc, conpsl;                            /* console reg */
@@ -72,9 +65,7 @@ t_stat sysd_reset (DEVICE *dptr);
 const char *sysd_description (DEVICE *dptr);
 t_stat vax610_boot (int32 flag, char *ptr);
 t_stat vax610_boot_parse (int32 flag, char *ptr);
-t_stat cpu_boot (int32 unitno, DEVICE *dptr);
 
-extern int32 intexc (int32 vec, int32 cc, int32 ipl, int ei);
 extern int32 vc_mem_rd (int32 pa);
 extern void vc_mem_wr (int32 pa, int32 val, int32 lnt);
 extern int32 iccs_rd (void);
@@ -88,7 +79,6 @@ extern void rxcs_wr (int32 dat);
 extern void txcs_wr (int32 dat);
 extern void txdb_wr (int32 dat);
 extern void ioreset_wr (int32 dat);
-extern int32 eval_int (void);
 
 /* SYSD data structures
 
diff --git a/VAX/vax610_syslist.c b/VAX/vax610_syslist.c
index 35c808f6..aab1062d 100644
--- a/VAX/vax610_syslist.c
+++ b/VAX/vax610_syslist.c
@@ -59,9 +59,6 @@ extern DEVICE vc_dev;
 extern DEVICE lk_dev;
 extern DEVICE vs_dev;
 
-extern void WriteB (uint32 pa, int32 val);
-extern UNIT cpu_unit;
-
 DEVICE *sim_devices[] = { 
     &cpu_dev,
     &mctl_dev,
diff --git a/VAX/vax630_defs.h b/VAX/vax630_defs.h
index 20b115bd..9bdddcd6 100644
--- a/VAX/vax630_defs.h
+++ b/VAX/vax630_defs.h
@@ -381,6 +381,7 @@ typedef struct {
 #define SET_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] | (INT_##dv)
 #define CLR_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] & ~(INT_##dv)
 #define IORETURN(f,v)   ((f)? (v): SCPE_OK)             /* cond error return */
+extern int32 int_req[IPL_HLVL];                         /* intr, IPL 14-17 */
 
 /* Logging */
 
diff --git a/VAX/vax630_io.c b/VAX/vax630_io.c
index fa771e84..1c6734ac 100644
--- a/VAX/vax630_io.c
+++ b/VAX/vax630_io.c
@@ -73,12 +73,6 @@ int32 qb_ipc = 0;                                       /* IPC */
 int32 qb_map[QBNMAPR] = { 0 };                          /* map registers */
 int32 autcon_enb = 1;                                   /* autoconfig enable */
 
-extern int32 R[16];
-extern uint32 *M;
-extern UNIT cpu_unit;
-extern int32 PSL, SISR, trpirq, mem_err, hlt_pin;
-extern int32 p1;
-extern jmp_buf save_env;
 extern int32 ka_mser;                                   /* KA630 mem sys err */
 
 t_stat dbl_rd (int32 *data, int32 addr, int32 access);
diff --git a/VAX/vax630_stddev.c b/VAX/vax630_stddev.c
index 30d5b955..3b264450 100644
--- a/VAX/vax630_stddev.c
+++ b/VAX/vax630_stddev.c
@@ -48,9 +48,6 @@
 #define CLK_DELAY       5000                            /* 100 Hz */
 #define TMXR_MULT       1                               /* 100 Hz */
 
-extern int32 int_req[IPL_HLVL];
-extern int32 hlt_pin;
-
 int32 tti_csr = 0;                                      /* control/status */
 uint32 tti_buftime;                                     /* time input character arrived */
 int32 tto_csr = 0;                                      /* control/status */
diff --git a/VAX/vax630_sysdev.c b/VAX/vax630_sysdev.c
index cf5ad99e..4e9d2a9c 100644
--- a/VAX/vax630_sysdev.c
+++ b/VAX/vax630_sysdev.c
@@ -121,23 +121,7 @@ CTAB vax630_cmd[] = {
 #define DEAR_LMADD      0x00007FFF                      /* local mem addr */
 #define DEAR_RD         (DEAR_LMADD)
 
-extern int32 R[16];
-extern int32 STK[5];
-extern int32 PSL;
-extern int32 SISR;
-extern int32 SCBB;
-extern int32 mapen;
-extern int32 pcq[PCQ_SIZE];
-extern int32 pcq_p;
-extern int32 ibcnt, ppc;
-extern int32 in_ie;
-extern int32 mchk_va, mchk_ref;
-extern int32 fault_PC;
-extern int32 int_req[IPL_HLVL];
-extern UNIT cpu_unit;
 extern UNIT clk_unit;
-extern jmp_buf save_env;
-extern int32 p1;
 extern int32 tmr_poll;
 extern DEVICE vc_dev, lk_dev, vs_dev;
 
@@ -178,7 +162,6 @@ void ka_wr (int32 pa, int32 val, int32 lnt);
 t_stat sysd_powerup (void);
 int32 con_halt (int32 code, int32 cc);
 
-extern int32 intexc (int32 vec, int32 cc, int32 ipl, int ei);
 extern int32 qbmap_rd (int32 pa);
 extern void qbmap_wr (int32 pa, int32 val, int32 lnt);
 extern int32 qbmem_rd (int32 pa);
diff --git a/VAX/vax630_syslist.c b/VAX/vax630_syslist.c
index 1a136326..eef863b8 100644
--- a/VAX/vax630_syslist.c
+++ b/VAX/vax630_syslist.c
@@ -70,10 +70,6 @@ extern DEVICE vc_dev;
 extern DEVICE lk_dev;
 extern DEVICE vs_dev;
 
-extern void WriteB (uint32 pa, int32 val);
-extern void rom_wr_B (int32 pa, int32 val);
-extern UNIT cpu_unit;
-
 DEVICE *sim_devices[] = { 
     &cpu_dev,
     &tlb_dev,
diff --git a/VAX/vax730_defs.h b/VAX/vax730_defs.h
index a91d438e..ad62d20c 100644
--- a/VAX/vax730_defs.h
+++ b/VAX/vax730_defs.h
@@ -341,6 +341,7 @@ typedef struct {
 #define SET_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] | (INT_##dv)
 #define CLR_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] & ~(INT_##dv)
 #define IORETURN(f,v)   ((f)? (v): SCPE_OK)             /* cond error return */
+extern int32 int_req[IPL_HLVL];                         /* intr, IPL 14-17 */
 
 /* Logging */
 
diff --git a/VAX/vax730_mem.c b/VAX/vax730_mem.c
index 6a3e0d06..90fdb9d5 100644
--- a/VAX/vax730_mem.c
+++ b/VAX/vax730_mem.c
@@ -65,8 +65,6 @@
 
 #define MEM_BOARD_MASK(x,y)  ((1u << (uint32)(x/y)) - 1)
 
-extern UNIT cpu_unit;
-
 uint32 mcsr0 = 0;
 uint32 mcsr1 = 0;
 uint32 mcsr2 = 0;
diff --git a/VAX/vax730_rb.c b/VAX/vax730_rb.c
index 56866c81..51a196fa 100644
--- a/VAX/vax730_rb.c
+++ b/VAX/vax730_rb.c
@@ -197,8 +197,6 @@
 #define DBG_RD          0x0004                          /* disk reads */
 #define DBG_WR          0x0008                          /* disk writes */
 
-extern int32 int_req[IPL_HLVL];
-
 uint16 *rbxb = NULL;                                     /* xfer buffer */
 int32 rbcs = 0;                                         /* control/status */
 int32 rbba = 0;                                         /* memory address */
diff --git a/VAX/vax730_stddev.c b/VAX/vax730_stddev.c
index d04420e0..9a4ba511 100644
--- a/VAX/vax730_stddev.c
+++ b/VAX/vax730_stddev.c
@@ -185,8 +185,6 @@ typedef struct todr_battery_info TOY;
 
 int32 td_regval;                                        /* temp location used in reg declarations */
 
-extern jmp_buf save_env;
-
 t_stat tti_svc (UNIT *uptr);
 t_stat tto_svc (UNIT *uptr);
 t_stat clk_svc (UNIT *uptr);
diff --git a/VAX/vax730_sys.c b/VAX/vax730_sys.c
index ff6e853e..abb3bb5b 100644
--- a/VAX/vax730_sys.c
+++ b/VAX/vax730_sys.c
@@ -68,24 +68,13 @@ static struct boot_dev boot_tab[] = {
     { NULL }
     };
 
-extern int32 R[16];
-extern int32 PSL;
-extern int32 ASTLVL, SISR;
-extern int32 mapen, pme, trpirq;
-extern int32 in_ie;
-extern int32 mchk_va, mchk_ref;
-extern int32 crd_err, mem_err, hlt_pin;
 extern int32 tmr_int, tti_int, tto_int, csi_int, cso_int;
-extern jmp_buf save_env;
-extern int32 p1;
 
 t_stat sysb_reset (DEVICE *dptr);
 const char *sysb_description (DEVICE *dptr);
 t_stat vax730_boot (int32 flag, char *ptr);
 t_stat vax730_boot_parse (int32 flag, char *ptr);
-t_stat cpu_boot (int32 unitno, DEVICE *dptr);
 
-extern int32 intexc (int32 vec, int32 cc, int32 ipl, int ei);
 extern int32 iccs_rd (void);
 extern int32 nicr_rd (void);
 extern int32 icr_rd (t_bool interp);
diff --git a/VAX/vax730_syslist.c b/VAX/vax730_syslist.c
index 54c4b1f0..08f9ac4c 100644
--- a/VAX/vax730_syslist.c
+++ b/VAX/vax730_syslist.c
@@ -55,9 +55,6 @@ extern DEVICE vh_dev;
 extern DEVICE xu_dev, xub_dev;
 extern DEVICE dmc_dev;
 
-extern UNIT cpu_unit;
-extern void WriteB (uint32 pa, int32 val);
-
 DEVICE *sim_devices[] = { 
     &cpu_dev,
     &tlb_dev,
diff --git a/VAX/vax730_uba.c b/VAX/vax730_uba.c
index 76ecaf85..731fc546 100644
--- a/VAX/vax730_uba.c
+++ b/VAX/vax730_uba.c
@@ -93,11 +93,7 @@ uint32 uba_fmer = 0;                                    /* failing map reg */
 uint32 uba_map[UBA_NMAPR] = { 0 };                      /* map registers */
 int32 autcon_enb = 1;                                   /* autoconfig enable */
 
-extern int32 trpirq;
 extern int32 autcon_enb;
-extern jmp_buf save_env;
-extern UNIT cpu_unit;
-extern int32 p1;
 
 t_stat uba_reset (DEVICE *dptr);
 const char *uba_description (DEVICE *dptr);
diff --git a/VAX/vax750_cmi.c b/VAX/vax750_cmi.c
index 25c0b556..2e3ee396 100644
--- a/VAX/vax750_cmi.c
+++ b/VAX/vax750_cmi.c
@@ -83,28 +83,17 @@ uint32 vax750_wcsmem[16384];
 static t_stat (*nexusR[NEXUS_NUM])(int32 *dat, int32 ad, int32 md);
 static t_stat (*nexusW[NEXUS_NUM])(int32 dat, int32 ad, int32 md);
 
-extern int32 R[16];
-extern int32 PSL;
 extern uint32 rom[ROMSIZE/sizeof(uint32)];                     /* boot ROM */
-extern int32 ASTLVL, SISR;
-extern int32 mapen, pme, trpirq;
-extern int32 in_ie;
-extern int32 mchk_va, mchk_ref;
-extern int32 crd_err, mem_err, hlt_pin;
 extern int32 tmr_int, tti_int, tto_int, csi_int, cso_int;
-extern jmp_buf save_env;
-extern int32 p1;
 
 t_stat cmi_reset (DEVICE *dptr);
 const char *cmi_description (DEVICE *dptr);
 void cmi_set_tmo (void);
 t_stat vax750_boot (int32 flag, char *ptr);
 t_stat vax750_boot_parse (int32 flag, char *ptr);
-t_stat cpu_boot (int32 unitno, DEVICE *dptr);
 t_stat vax750_set_bootdev (UNIT *uptr, int32 val, char *cptr, void *desc);
 t_stat vax750_show_bootdev (FILE *st, UNIT *uptr, int32 val, void *desc);
 
-extern int32 intexc (int32 vec, int32 cc, int32 ipl, int ei);
 extern int32 iccs_rd (void);
 extern int32 nicr_rd (void);
 extern int32 icr_rd (t_bool interp);
diff --git a/VAX/vax750_defs.h b/VAX/vax750_defs.h
index 62f46562..c4d9b360 100644
--- a/VAX/vax750_defs.h
+++ b/VAX/vax750_defs.h
@@ -381,6 +381,7 @@ typedef struct {
 #define SET_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] | (INT_##dv)
 #define CLR_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] & ~(INT_##dv)
 #define IORETURN(f,v)   ((f)? (v): SCPE_OK)             /* cond error return */
+extern int32 int_req[IPL_HLVL];                         /* intr, IPL 14-17 */
 
 /* Logging */
 
diff --git a/VAX/vax750_mem.c b/VAX/vax750_mem.c
index 4741e814..c742b0de 100644
--- a/VAX/vax750_mem.c
+++ b/VAX/vax750_mem.c
@@ -90,8 +90,6 @@
 #define MEM_256K_MASK    0x5555
 #define MEM_BOARD_MASK_256K(x) ((((1u << (uint32)(x/MEM_SIZE_256K)) - 1) & MEM_256K_MASK) | MCSR2_CS256)
 
-extern UNIT cpu_unit;
-
 uint32 mcsr0 = 0;
 uint32 mcsr1 = 0;
 uint32 mcsr2 = 0;
diff --git a/VAX/vax750_stddev.c b/VAX/vax750_stddev.c
index 7e89ea4d..6558bd23 100644
--- a/VAX/vax750_stddev.c
+++ b/VAX/vax750_stddev.c
@@ -175,8 +175,6 @@ typedef struct todr_battery_info TOY;
 
 int32 td_regval;                                        /* temp location used in reg declarations */
 
-extern jmp_buf save_env;
-
 t_stat tti_svc (UNIT *uptr);
 t_stat tto_svc (UNIT *uptr);
 t_stat clk_svc (UNIT *uptr);
diff --git a/VAX/vax750_syslist.c b/VAX/vax750_syslist.c
index ae6384ad..9445c658 100644
--- a/VAX/vax750_syslist.c
+++ b/VAX/vax750_syslist.c
@@ -57,10 +57,6 @@ extern DEVICE vh_dev;
 extern DEVICE xu_dev, xub_dev;
 extern DEVICE dmc_dev;
 
-extern void WriteB (uint32 pa, int32 val);
-extern void rom_wr_B (int32 pa, int32 val);
-extern UNIT cpu_unit;
-
 DEVICE *sim_devices[] = { 
     &cpu_dev,
     &tlb_dev,
diff --git a/VAX/vax750_uba.c b/VAX/vax750_uba.c
index 431cb374..bd789037 100644
--- a/VAX/vax750_uba.c
+++ b/VAX/vax750_uba.c
@@ -98,14 +98,8 @@ uint32 uba_dpr[UBA_NDPATH] = { 0 };                     /* number data paths */
 uint32 uba_map[UBA_NMAPR] = { 0 };                      /* map registers */
 int32 autcon_enb = 1;                                   /* autoconfig enable */
 
-extern int32 trpirq;
 extern int32 autcon_enb;
-extern jmp_buf save_env;
-extern UNIT cpu_unit;
 extern uint32 nexus_req[NEXUS_HLVL];
-extern int32 p1;
-extern int32 fault_PC;                                  /* fault PC */
-extern int32 mem_err;
 
 t_stat uba_reset (DEVICE *dptr);
 const char *uba_description (DEVICE *dptr);
diff --git a/VAX/vax780_defs.h b/VAX/vax780_defs.h
index fdaf34e4..477e5a14 100644
--- a/VAX/vax780_defs.h
+++ b/VAX/vax780_defs.h
@@ -394,6 +394,7 @@ typedef struct {
 #define SET_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] | (INT_##dv)
 #define CLR_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] & ~(INT_##dv)
 #define IORETURN(f,v)   ((f)? (v): SCPE_OK)             /* cond error return */
+extern int32 int_req[IPL_HLVL];                         /* intr, IPL 14-17 */
 
 /* Logging */
 
diff --git a/VAX/vax780_fload.c b/VAX/vax780_fload.c
index fc304f74..c66779a8 100644
--- a/VAX/vax780_fload.c
+++ b/VAX/vax780_fload.c
@@ -77,7 +77,6 @@
 #define DE_SIZE         7                               /* entry size in words */
 #define DE_GET_STAT(x)  (((x) >> 8) & 0377)
 
-extern UNIT cpu_unit;
 extern UNIT fl_unit;
 
 t_bool rtfile_parse (char *pntr, uint16 *file_name);
diff --git a/VAX/vax780_mem.c b/VAX/vax780_mem.c
index 8b573bd5..8e02631a 100644
--- a/VAX/vax780_mem.c
+++ b/VAX/vax780_mem.c
@@ -88,8 +88,6 @@ uint32 mcr_c[MCTL_NUM];
 uint32 mcr_d[MCTL_NUM];
 uint32 rom_lw[MCTL_NUM][ROMSIZE >> 2];
 
-extern UNIT cpu_unit;
-
 t_stat mctl_reset (DEVICE *dptr);
 const char *mctl_description (DEVICE *dptr);
 t_stat mctl_rdreg (int32 *val, int32 pa, int32 mode);
diff --git a/VAX/vax780_sbi.c b/VAX/vax780_sbi.c
index 570b843e..95088575 100644
--- a/VAX/vax780_sbi.c
+++ b/VAX/vax780_sbi.c
@@ -128,16 +128,7 @@ static struct boot_dev boot_tab[] = {
     { NULL }
     };
 
-extern int32 R[16];
-extern int32 PSL;
-extern int32 ASTLVL, SISR;
-extern int32 mapen, pme, trpirq;
-extern int32 in_ie;
-extern int32 mchk_va, mchk_ref;
-extern int32 crd_err, mem_err, hlt_pin;
 extern int32 tmr_int, tti_int, tto_int;
-extern jmp_buf save_env;
-extern int32 p1;
 
 t_stat sbi_reset (DEVICE *dptr);
 const char *sbi_description (DEVICE *dptr);
@@ -145,10 +136,8 @@ void sbi_set_tmo (int32 pa);
 void uba_eval_int (void);
 t_stat vax780_boot (int32 flag, char *ptr);
 t_stat vax780_boot_parse (int32 flag, char *ptr);
-t_stat cpu_boot (int32 unitno, DEVICE *dptr);
 
 extern t_stat vax780_fload (int32 flag, char *cptr);
-extern int32 intexc (int32 vec, int32 cc, int32 ipl, int ei);
 extern int32 iccs_rd (void);
 extern int32 nicr_rd (void);
 extern int32 icr_rd (void);
diff --git a/VAX/vax780_stddev.c b/VAX/vax780_stddev.c
index 9e989914..cb028068 100644
--- a/VAX/vax780_stddev.c
+++ b/VAX/vax780_stddev.c
@@ -219,8 +219,6 @@ int32 fl_bptr = 0;                                      /* buffer pointer */
 
 uint8 comm_region[COMM_LNT] = { 0 };                    /* comm region */
 
-extern jmp_buf save_env;
-
 t_stat tti_svc (UNIT *uptr);
 t_stat tto_svc (UNIT *uptr);
 t_stat clk_svc (UNIT *uptr);
diff --git a/VAX/vax780_syslist.c b/VAX/vax780_syslist.c
index d71f41c4..87184e4c 100644
--- a/VAX/vax780_syslist.c
+++ b/VAX/vax780_syslist.c
@@ -64,10 +64,6 @@ extern DEVICE vh_dev;
 extern DEVICE xu_dev, xub_dev;
 extern DEVICE dmc_dev;
 
-extern UNIT cpu_unit;
-extern void WriteB (uint32 pa, int32 val);
-extern void rom_wr_B (int32 pa, int32 val);
-
 DEVICE *sim_devices[] = { 
     &cpu_dev,
     &tlb_dev,
diff --git a/VAX/vax780_uba.c b/VAX/vax780_uba.c
index 66cf8ba1..43d445c4 100644
--- a/VAX/vax780_uba.c
+++ b/VAX/vax780_uba.c
@@ -177,10 +177,7 @@ uint32 uba_aitime = 250;                                /* adapter init time */
 uint32 uba_uitime = 12250;                              /* Unibus init time */
 int32 autcon_enb = 1;                                   /* autoconfig enable */
 
-extern int32 trpirq;
 extern int32 autcon_enb;
-extern jmp_buf save_env;
-extern UNIT cpu_unit;
 extern uint32 nexus_req[NEXUS_HLVL];
 
 t_stat uba_svc (UNIT *uptr);
diff --git a/VAX/vax7x0_mba.c b/VAX/vax7x0_mba.c
index fe643a47..cfff1f4f 100644
--- a/VAX/vax7x0_mba.c
+++ b/VAX/vax7x0_mba.c
@@ -252,7 +252,6 @@ uint32 mba_smr[MBA_NUM];                                /* sel map reg */
 uint32 mba_map[MBA_NUM][MBA_NMAPR];                     /* map */
 
 extern uint32 nexus_req[NEXUS_HLVL];
-extern UNIT cpu_unit;
 
 t_stat mba_reset (DEVICE *dptr);
 t_stat mba_help (FILE *st, DEVICE *dptr, UNIT *uptr, int32 flag, const char *cptr);
diff --git a/VAX/vax860_abus.c b/VAX/vax860_abus.c
index ccf70e8d..f4d44ba9 100644
--- a/VAX/vax860_abus.c
+++ b/VAX/vax860_abus.c
@@ -107,31 +107,18 @@ static struct boot_dev boot_tab[] = {
     { NULL }
     };
 
-extern int32 R[16];
-extern int32 PSL;
-extern int32 ASTLVL, SISR;
-extern int32 mapen, pme, trpirq;
-extern int32 in_ie;
-extern int32 mchk_va, mchk_ref;
-extern int32 crd_err, mem_err, hlt_pin;
 extern int32 tmr_int, tti_int, tto_int, csi_int;
 extern uint32 sbi_er;
-extern jmp_buf save_env;
-extern int32 p1;
-extern int32 fault_PC;                                  /* fault PC */
-extern UNIT cpu_unit;
 
 void uba_eval_int (void);
 t_stat abus_reset (DEVICE *dptr);
 const char *abus_description (DEVICE *dptr);
 t_stat vax860_boot (int32 flag, char *ptr);
 t_stat vax860_boot_parse (int32 flag, char *ptr);
-t_stat cpu_boot (int32 unitno, DEVICE *dptr);
 void init_pamm (void);
 
 extern t_stat (*nexusR[NEXUS_NUM])(int32 *dat, int32 ad, int32 md);
 extern t_stat (*nexusW[NEXUS_NUM])(int32 dat, int32 ad, int32 md);
-extern int32 intexc (int32 vec, int32 cc, int32 ipl, int ei);
 extern int32 iccs_rd (void);
 extern int32 nicr_rd (void);
 extern int32 icr_rd (t_bool interp);
diff --git a/VAX/vax860_defs.h b/VAX/vax860_defs.h
index aae3318b..9b278247 100644
--- a/VAX/vax860_defs.h
+++ b/VAX/vax860_defs.h
@@ -424,6 +424,7 @@ typedef struct {
 #define SET_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] | (INT_##dv)
 #define CLR_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] & ~(INT_##dv)
 #define IORETURN(f,v)   ((f)? (v): SCPE_OK)             /* cond error return */
+extern int32 int_req[IPL_HLVL];                         /* intr, IPL 14-17 */
 
 /* Logging */
 
diff --git a/VAX/vax860_sbia.c b/VAX/vax860_sbia.c
index 4ceefd39..be1b3107 100644
--- a/VAX/vax860_sbia.c
+++ b/VAX/vax860_sbia.c
@@ -80,17 +80,6 @@ uint32 sbi_er = 0;                                      /* SBI error status */
 uint32 sbi_tmo = 0;                                     /* SBI timeout addr */
 uint32 sbi_csr = 0;                                     /* SBI control/status */
 
-extern int32 R[16];
-extern int32 PSL;
-extern int32 ASTLVL, SISR;
-extern jmp_buf save_env;
-extern int32 trpirq;
-extern int32 p1;
-extern int32 mchk_ref;
-extern int32 crd_err;
-extern int32 fault_PC;                                  /* fault PC */
-extern UNIT cpu_unit;
-
 t_stat sbia_reset (DEVICE *dptr);
 const char *sbia_description (DEVICE *dptr);
 void sbi_set_tmo (int32 pa);
diff --git a/VAX/vax860_stddev.c b/VAX/vax860_stddev.c
index 09a8e512..9ec923f2 100644
--- a/VAX/vax860_stddev.c
+++ b/VAX/vax860_stddev.c
@@ -233,10 +233,6 @@ int32 rlcs_mp = 0;
 int32 rlcs_bcnt = 0;                                    /* byte count */
 uint16 *rlcs_buf = NULL;
 
-extern jmp_buf save_env;
-extern UNIT cpu_unit;
-extern int32 brk_req;
-
 t_stat tti_svc (UNIT *uptr);
 t_stat tto_svc (UNIT *uptr);
 t_stat clk_svc (UNIT *uptr);
diff --git a/VAX/vax860_syslist.c b/VAX/vax860_syslist.c
index a311e6fd..1281cd27 100644
--- a/VAX/vax860_syslist.c
+++ b/VAX/vax860_syslist.c
@@ -64,9 +64,6 @@ extern DEVICE vh_dev;
 extern DEVICE xu_dev, xub_dev;
 extern DEVICE dmc_dev;
 
-extern UNIT cpu_unit;
-extern void WriteB (uint32 pa, int32 val);
-
 DEVICE *sim_devices[] = { 
     &cpu_dev,
     &tlb_dev,
diff --git a/VAX/vax_cis.c b/VAX/vax_cis.c
index e15eb23b..23521aed 100644
--- a/VAX/vax_cis.c
+++ b/VAX/vax_cis.c
@@ -74,14 +74,6 @@ typedef struct {
 static DSTR Dstr_zero = { 0, {0, 0, 0, 0} };
 static DSTR Dstr_one = { 0, {0x10, 0, 0, 0} };
 
-extern int32 R[16];
-extern int32 PSL;
-extern int32 trpirq;
-extern int32 p1;
-extern int32 fault_PC;
-extern int32 ibcnt, ppc;
-extern jmp_buf save_env;
-
 int32 ReadDstr (int32 lnt, int32 addr, DSTR *dec, int32 acc);
 int32 WriteDstr (int32 lnt, int32 addr, DSTR *dec, int32 v, int32 acc);
 int32 SetCCDstr (int32 lnt, DSTR *src, int32 pslv);
@@ -1653,15 +1645,6 @@ return sign;
 
 #else
 
-extern int32 R[16];
-extern int32 PSL;
-extern int32 SCBB;
-extern int32 fault_PC;
-extern int32 ibcnt, ppc;
-extern int32 pcq[PCQ_SIZE];
-extern int32 pcq_p;
-extern jmp_buf save_env;
-
 /* CIS instructions - invoke emulator interface
 
         opnd[0:5] =     six operands to be pushed (if PSL<fpd> = 0)
diff --git a/VAX/vax_cmode.c b/VAX/vax_cmode.c
index 72ce6302..e97e1e8e 100644
--- a/VAX/vax_cmode.c
+++ b/VAX/vax_cmode.c
@@ -49,18 +49,6 @@
 #define CC_XOR_NV(x)    ((((x) & CC_N) != 0) ^ (((x) & CC_V) != 0))
 #define CC_XOR_NC(x)    ((((x) & CC_N) != 0) ^ (((x) & CC_C) != 0))
 
-extern int32 R[16];
-extern int32 PSL;
-extern int32 trpirq;
-extern int32 p1;
-extern int32 fault_PC;
-extern int32 recq[];                                    /* recovery queue */
-extern int32 recqptr;                                   /* recq pointer */
-extern int32 pcq[];
-extern int32 pcq_p;
-extern int32 ibcnt, ppc;
-extern jmp_buf save_env;
-
 int32 GeteaB (int32 spec);
 int32 GeteaW (int32 spec);
 int32 RdMemW (int32 a);
@@ -1312,8 +1300,6 @@ return;
    Should never get to instruction execution
 */
 
-extern jmp_buf save_env;
-
 t_bool BadCmPSL (int32 newpsl)
 {
 return TRUE;                                            /* always bad */
diff --git a/VAX/vax_cpu.c b/VAX/vax_cpu.c
index 89526015..9e3ba938 100644
--- a/VAX/vax_cpu.c
+++ b/VAX/vax_cpu.c
@@ -182,7 +182,6 @@
 
 #include "vax_defs.h"
 
-#define OP_MEM          -1
 #define UNIT_V_CONH     (UNIT_V_UF + 0)                 /* halt to console */
 #define UNIT_V_MSIZE    (UNIT_V_UF + 1)                 /* dummy */
 #define UNIT_CONH       (1u << UNIT_V_CONH)
@@ -314,79 +313,8 @@ const uint32 align[4] = {
 
 /* External and forward references */
 
-extern t_stat build_dib_tab (void);
-extern UNIT rom_unit, nvr_unit;
 extern int32 sys_model;
-extern int32 op_ashq (int32 *opnd, int32 *rh, int32 *flg);
-extern int32 op_emul (int32 mpy, int32 mpc, int32 *rh);
-extern int32 op_ediv (int32 *opnd, int32 *rh, int32 *flg);
-extern int32 op_bb_n (int32 *opnd, int32 acc);
-extern int32 op_bb_x (int32 *opnd, int32 newb, int32 acc);
-extern int32 op_extv (int32 *opnd, int32 vfldrp1, int32 acc);
-extern int32 op_ffs (uint32 fld, int32 size);
-extern void op_insv (int32 *opnd, int32 vfldrp1, int32 acc);
-extern int32 op_call (int32 *opnd, t_bool gs, int32 acc);
-extern int32 op_ret (int32 acc);
-extern int32 op_insque (int32 *opnd, int32 acc);
-extern int32 op_remque (int32 *opnd, int32 acc);
-extern int32 op_insqhi (int32 *opnd, int32 acc);
-extern int32 op_insqti (int32 *opnd, int32 acc);
-extern int32 op_remqhi (int32 *opnd, int32 acc);
-extern int32 op_remqti (int32 *opnd, int32 acc);
-extern void op_pushr (int32 *opnd, int32 acc);
-extern void op_popr (int32 *opnd, int32 acc);
-extern int32 op_movc (int32 *opnd, int32 opc, int32 acc);
-extern int32 op_cmpc (int32 *opnd, int32 opc, int32 acc);
-extern int32 op_locskp (int32 *opnd, int32 opc, int32 acc);
-extern int32 op_scnspn (int32 *opnd, int32 opc, int32 acc);
-extern int32 op_chm (int32 *opnd, int32 cc, int32 opc);
-extern int32 op_rei (int32 acc);
-extern void op_ldpctx (int32 acc);
-extern void op_svpctx (int32 acc);
-extern int32 op_probe (int32 *opnd, int32 opc);
-extern int32 op_mtpr (int32 *opnd);
-extern int32 op_mfpr (int32 *opnd);
-extern int32 op_movfd (int32 val);
-extern int32 op_movg (int32 val);
-extern int32 op_mnegfd (int32 val);
-extern int32 op_mnegg (int32 val);
-extern int32 op_cmpfd (int32 h1, int32 l1, int32 h2, int32 l2);
-extern int32 op_cmpg (int32 h1, int32 l1, int32 h2, int32 l2);
-extern int32 op_cvtifdg (int32 val, int32 *rh, int32 opc);
-extern int32 op_cvtfdgi (int32 *opnd, int32 *flg, int32 opc);
-extern int32 op_cvtdf (int32 *opnd);
-extern int32 op_cvtgf (int32 *opnd);
-extern int32 op_cvtfg (int32 *opnd, int32 *rh);
-extern int32 op_cvtgh (int32 *opnd, int32 *hflt);
-extern int32 op_addf (int32 *opnd, t_bool sub);
-extern int32 op_addd (int32 *opnd, int32 *rh, t_bool sub);
-extern int32 op_addg (int32 *opnd, int32 *rh, t_bool sub);
-extern int32 op_mulf (int32 *opnd);
-extern int32 op_muld (int32 *opnd, int32 *rh);
-extern int32 op_mulg (int32 *opnd, int32 *rh);
-extern int32 op_divf (int32 *opnd);
-extern int32 op_divd (int32 *opnd, int32 *rh);
-extern int32 op_divg (int32 *opnd, int32 *rh);
-extern int32 op_emodf (int32 *opnd, int32 *intgr, int32 *flg);
-extern int32 op_emodd (int32 *opnd, int32 *rh, int32 *intgr, int32 *flg);
-extern int32 op_emodg (int32 *opnd, int32 *rh, int32 *intgr, int32 *flg);
-extern void op_polyf (int32 *opnd, int32 acc);
-extern void op_polyd (int32 *opnd, int32 acc);
-extern void op_polyg (int32 *opnd, int32 acc);
-extern int32 op_cmode (int32 cc);
-extern int32 op_cis (int32 *opnd, int32 cc, int32 opc, int32 acc);
-extern int32 op_octa (int32 *opnd, int32 cc, int32 opc, int32 acc, int32 spec, int32 va);
-extern int32 intexc (int32 vec, int32 cc, int32 ipl, int ei);
-extern int32 Test (uint32 va, int32 acc, int32 *status);
-extern int32 BadCmPSL (int32 newpsl);
-extern int32 eval_int (void);
-extern int32 get_vector (int32 lvl);
-extern void set_map_reg (void);
-extern void rom_wr_B (int32 pa, int32 val);
-extern int32 machine_check (int32 p1, int32 opc, int32 cc, int32 delta);
-extern const uint16 drom[NUM_INST][MAX_SPEC + 1];
-extern t_stat cpu_boot (int32 unitno, DEVICE *dptr);
-extern int32 con_halt (int32 code, int32 cc);
+extern const char *opcode[];
 
 t_stat cpu_reset (DEVICE *dptr);
 t_bool cpu_is_pc_a_subroutine_call (t_addr **ret_addrs);
@@ -3550,8 +3478,6 @@ t_stat cpu_show_hist_records (FILE *st, t_bool do_header, int32 start, int32 cou
 {
 int32 i, k, numspec;
 InstHistory *h;
-extern const char *opcode[];
-extern t_value *sim_eval;
 
 if (hst_lnt == 0)                                       /* enabled? */
     return SCPE_NOFNC;
diff --git a/VAX/vax_cpu1.c b/VAX/vax_cpu1.c
index ae483ab5..1476f5bc 100644
--- a/VAX/vax_cpu1.c
+++ b/VAX/vax_cpu1.c
@@ -82,37 +82,12 @@ static const uint8 rcnt[128] = {
 12,16,16,20,16,20,20,24,16,20,20,24,20,24,24,28         /* 70 - 7F */
 };
 
-int32 last_chm = 0;
-
-extern uint32 *M;
 extern const uint32 byte_mask[33];
-extern int32 R[16];
-extern int32 STK[5];
-extern int32 PSL;
-extern int32 SCBB, PCBB, SBR, SLR;
-extern int32 P0BR, P0LR, P1BR, P1LR;
-extern int32 ASTLVL, SISR, mapen;
-extern int32 pme;
-extern int32 trpirq;
-extern int32 p1, p2;
-extern int32 fault_PC;
-extern int32 pcq[PCQ_SIZE];
-extern int32 pcq_p;
-extern int32 in_ie;
-extern int32 ibcnt, ppc;
-extern DEVICE cpu_dev;
 
-extern int32 Test (uint32 va, int32 acc, int32 *status);
-extern void set_map_reg (void);
-extern void zap_tb (int stb);
-extern void zap_tb_ent (uint32 va);
-extern t_bool chk_tb_ent (uint32 va);
 extern int32 ReadIPR (int32 rg);
 extern void WriteIPR (int32 rg, int32 val);
 extern t_bool BadCmPSL (int32 newpsl);
 
-extern jmp_buf save_env;
-
 /* Branch on bit and no modify
    Branch on bit and modify
 
@@ -126,9 +101,10 @@ int32 op_bb_n (int32 *opnd, int32 acc)
 {
 int32 pos = opnd[0];
 int32 rn = opnd[1];
-int32 ea, by;
+int32 ea;
+int32 by;
 
-if (rn >= 0) {                                          /* register? */
+if (rn != OP_MEM) {                                     /* register? */
     if (((uint32) pos) > 31)                            /* pos > 31? fault */
         RSVD_OPND_FAULT;
     return (R[rn] >> pos) & 1;                          /* get bit */
@@ -143,9 +119,10 @@ int32 op_bb_x (int32 *opnd, int32 newb, int32 acc)
 {
 int32 pos = opnd[0];
 int32 rn = opnd[1];
-int32 ea, by, bit;
+int32 ea;
+int32 by, bit;
 
-if (rn >= 0) {                                          /* register? */
+if (rn != OP_MEM) {                                     /* register? */
     if (((uint32) pos) > 31)                            /* pos > 31? fault */
         RSVD_OPND_FAULT;
     bit = (R[rn] >> pos) & 1;                           /* get bit */
@@ -183,7 +160,7 @@ if (size == 0)                                          /* size 0? field = 0 */
     return 0;
 if (size > 32)                                          /* size > 32? fault */
     RSVD_OPND_FAULT;
-if (rn >= 0) {                                          /* register? */
+if (rn != OP_MEM) {                                     /* register? */
     if (((uint32) pos) > 31)                            /* pos > 31? fault */
         RSVD_OPND_FAULT;
     if (((pos + size) > 32) && (rn >= nSP))             /* span 2 reg, PC? */
@@ -227,7 +204,7 @@ if (size == 0)                                          /* size = 0? done */
     return;
 if (size > 32)                                          /* size > 32? fault */
     RSVD_OPND_FAULT;
-if (rn >= 0) {                                          /* in registers? */
+if (rn != OP_MEM) {                                     /* in registers? */
     if (((uint32) pos) > 31)                            /* pos > 31? fault */
         RSVD_OPND_FAULT;
     if ((pos + size) > 32) {                            /* span two reg? */
@@ -573,13 +550,13 @@ p = Read (e + 4, L_LONG, RA);                           /* p <- (e+4) */
 CC_CMP_L (s, p);                                        /* set cc's */
 if (e != p) {                                           /* queue !empty? */
     Read (s + 4, L_LONG, WA);                           /* wchk (s+4) */
-    if (opnd[1] < 0)                                    /* wchk dest */
+    if (opnd[1] == OP_MEM)                              /* wchk dest */
         Read (opnd[2], L_LONG, WA);
     Write (p, s, L_LONG, WA);                           /* (p) <- s */
     Write (s + 4, p, L_LONG, WA);                       /* (s+4) <- p */
     }
 else cc = cc | CC_V;                                    /* else set v */
-if (opnd[1] >= 0)                                       /* store result */
+if (opnd[1] != OP_MEM)                                  /* store result */
     R[opnd[1]] = e;
 else Write (opnd[2], e, L_LONG, WA);
 return cc;
@@ -619,7 +596,8 @@ int32 op_insqhi (int32 *opnd, int32 acc)
 {
 int32 h = opnd[1];
 int32 d = opnd[0];
-int32 a, t;
+int32 a;
+int32 t;
 
 if ((h == d) || ((h | d) & 07))                         /* h, d quad align? */
     RSVD_OPND_FAULT;
@@ -644,7 +622,8 @@ int32 op_insqti (int32 *opnd, int32 acc)
 {
 int32 h = opnd[1];
 int32 d = opnd[0];
-int32 a, c, t;
+int32 a, c;
+int32 t;
 
 if ((h == d) || ((h | d) & 07))                         /* h, d quad align? */
     RSVD_OPND_FAULT;
@@ -701,11 +680,12 @@ return 0;                                               /* q >= 2 entries */
 int32 op_remqhi (int32 *opnd, int32 acc)
 {
 int32 h = opnd[0];
-int32 ar, a, b, t;
+int32 ar, a, b;
+int32 t;
 
 if (h & 07)                                             /* h quad aligned? */
     RSVD_OPND_FAULT;
-if (opnd[1] < 0) {                                      /* mem destination? */
+if (opnd[1] == OP_MEM) {                                /* mem destination? */
     if (h == opnd[2])                                   /* hdr = dst? */
         RSVD_OPND_FAULT;
     Read (opnd[2], L_LONG, WA);                         /* wchk dst */
@@ -730,7 +710,7 @@ if (ar) {                                               /* queue not empty? */
     Write (b + 4, h - b, L_LONG, WA);                   /* (b+4) <- h-b, flt ok */
     Write (h, b - h, L_LONG, WA);                       /* (h) <- b-h, rls int */
     }
-if (opnd[1] >= 0)                                       /* store result */
+if (opnd[1] != OP_MEM)                                  /* store result */
     R[opnd[1]] = a;
 else Write (opnd[2], a, L_LONG, WA);
 if (ar == 0)                                            /* empty, cc = 0110 */
@@ -741,11 +721,12 @@ return (b == h)? CC_Z: 0;                               /* if b = h, q empty */
 int32 op_remqti (int32 *opnd, int32 acc)
 {
 int32 h = opnd[0];
-int32 ar, b, c, t;
+int32 ar, b, c;
+int32 t;
 
 if (h & 07)                                             /* h quad aligned? */
     RSVD_OPND_FAULT;
-if (opnd[1] < 0) {                                      /* mem destination? */
+if (opnd[1] == OP_MEM) {                                /* mem destination? */
     if (h == opnd[2])                                   /* hdr = dst? */
         RSVD_OPND_FAULT;
     Read (opnd[2], L_LONG, WA);                         /* wchk dst */
@@ -781,7 +762,7 @@ if (ar) {                                               /* queue not empty */
     Write (h, ar, L_LONG, WA);                          /* release interlock */
     }
 else c = h;                                             /* empty, result = h */
-if (opnd[1] >= 0)                                       /* store result */
+if (opnd[1] != OP_MEM)                                  /* store result */
     R[opnd[1]] = c;
 else Write (opnd[2], c, L_LONG, WA);
 if (ar == 0)                                            /* empty, cc = 0110 */
@@ -1167,7 +1148,8 @@ int32 op_chm (int32 *opnd, int32 cc, int32 opc)
 {
 int32 mode = opc & PSL_M_MODE;
 int32 cur = PSL_GETCUR (PSL);
-int32 tsp, newpc, acc, sta;
+int32 tsp, newpc, acc;
+int32 sta;
 
 if (PSL & PSL_IS)
     ABORT (STOP_CHMFI);
@@ -1191,7 +1173,6 @@ Write (tsp - 4, PSL | cc, L_LONG, WA);                  /* push PSL */
 SP = tsp - 12;                                          /* set new stk */
 PSL = (mode << PSL_V_CUR) | (PSL & PSL_IPL) |           /* set new PSL */
     (cur << PSL_V_PRV);                                 /* IPL unchanged */
-last_chm = fault_PC;
 JUMP (newpc & ~03);                                     /* set new PC */
 return 0;                                               /* cc = 0 */
 }
diff --git a/VAX/vax_defs.h b/VAX/vax_defs.h
index 745cedbf..68b00869 100644
--- a/VAX/vax_defs.h
+++ b/VAX/vax_defs.h
@@ -76,6 +76,7 @@
 #define ABORT_ACV       (-SCB_ACV)                      /* access violation */
 #define ABORT_TNV       (-SCB_TNV)                      /* transl not vaid */
 #define ABORT(x)        longjmp (save_env, (x))         /* abort */
+extern jmp_buf save_env;
 #define RSVD_INST_FAULT ABORT (ABORT_RESIN)
 #define RSVD_ADDR_FAULT ABORT (ABORT_RESAD)
 #define RSVD_OPND_FAULT ABORT (ABORT_RESOP)
@@ -743,6 +744,9 @@ enum opcodes {
             else cc = 0; \
             if (((uint32) s1) < ((uint32) s2)) cc = cc | CC_C
 
+/* Operand Memory vs Register Indicator */
+#define OP_MEM          0xFFFFFFFF
+
 #define VAX_IDLE_VMS        0x01
 #define VAX_IDLE_ULT        0x02    /* Ultrix more recent versions */
 #define VAX_IDLE_ULTOLD     0x04    /* Ultrix older versions */
@@ -754,7 +758,113 @@ enum opcodes {
 extern uint32 cpu_idle_mask;                            /* idle mask */
 void cpu_idle (void);
 
+/* CPU Register definitions */
+
+extern int32 R[16];                                     /* registers */
+extern int32 STK[5];                                    /* stack pointers */
+extern int32 PSL;                                       /* PSL */
+extern int32 SCBB;                                      /* SCB base */
+extern int32 PCBB;                                      /* PCB base */
+extern int32 SBR, SLR;                                  /* S0 mem mgt */                                          /* S0 mem mgt */
+extern int32 P0BR, P0LR;                                /* P0 mem mgt */
+extern int32 P1BR, P1LR;                                /* P1 mem mgt */
+extern int32 ASTLVL;                                    /* AST Level */
+extern int32 SISR;                                      /* swre int req */
+extern int32 pme;                                       /* perf mon enable */
+extern int32 trpirq;                                    /* trap/intr req */
+extern int32 fault_PC;                                  /* fault PC */
+extern int32 p1, p2;                                    /* fault parameters */
+extern int32 recq[];                                    /* recovery queue */
+extern int32 recqptr;                                   /* recq pointer */
+extern int32 pcq[PCQ_SIZE];                             /* PC queue */
+extern int32 pcq_p;                                     /* PC queue ptr */
+extern int32 in_ie;                                     /* in exc, int */
+extern int32 ibcnt, ppc;                                /* prefetch ctl */
+extern int32 hlt_pin;                                   /* HLT pin intr */
+extern int32 mem_err;
+extern int32 crd_err;
+
+/* vax_cpu1.c externals */
+extern int32 op_bb_n (int32 *opnd, int32 acc);
+extern int32 op_bb_x (int32 *opnd, int32 newb, int32 acc);
+extern int32 op_extv (int32 *opnd, int32 vfldrp1, int32 acc);
+extern void op_insv (int32 *opnd, int32 vfldrp1, int32 acc);
+extern int32 op_ffs (uint32 fld, int32 size);
+extern int32 op_call (int32 *opnd, t_bool gs, int32 acc);
+extern int32 op_ret (int32 acc);
+extern int32 op_insque (int32 *opnd, int32 acc);
+extern int32 op_remque (int32 *opnd, int32 acc);
+extern int32 op_insqhi (int32 *opnd, int32 acc);
+extern int32 op_insqti (int32 *opnd, int32 acc);
+extern int32 op_remqhi (int32 *opnd, int32 acc);
+extern int32 op_remqti (int32 *opnd, int32 acc);
+extern void op_pushr (int32 *opnd, int32 acc);
+extern void op_popr (int32 *opnd, int32 acc);
+extern int32 op_movc (int32 *opnd, int32 opc, int32 acc);
+extern int32 op_cmpc (int32 *opnd, int32 opc, int32 acc);
+extern int32 op_locskp (int32 *opnd, int32 opc, int32 acc);
+extern int32 op_scnspn (int32 *opnd, int32 opc, int32 acc);
+extern int32 op_chm (int32 *opnd, int32 cc, int32 opc);
+extern int32 op_rei (int32 acc);
+extern void op_ldpctx (int32 acc);
+extern void op_svpctx (int32 acc);
+extern int32 op_probe (int32 *opnd, int32 opc);
+extern int32 op_mtpr (int32 *opnd);
+extern int32 op_mfpr (int32 *opnd);
+extern int32 intexc (int32 vec, int32 cc, int32 ipl, int ei);
+
+/* vax_cis.c externals */
+extern int32 op_cis (int32 *opnd, int32 cc, int32 opc, int32 acc);
+
+/* vax_fpa.c externals */
+extern int32 op_ashq (int32 *opnd, int32 *rh, int32 *flg);
+extern int32 op_emul (int32 mpy, int32 mpc, int32 *rh);
+extern int32 op_ediv (int32 *opnd, int32 *rh, int32 *flg);
+extern int32 op_cmpfd (int32 h1, int32 l1, int32 h2, int32 l2);
+extern int32 op_cmpg (int32 h1, int32 l1, int32 h2, int32 l2);
+extern int32 op_cvtifdg (int32 val, int32 *rh, int32 opc);
+extern int32 op_cvtfdgi (int32 *opnd, int32 *flg, int32 opc);
+extern int32 op_emodf (int32 *opnd, int32 *intgr, int32 *flg);
+extern int32 op_emodd (int32 *opnd, int32 *rh, int32 *intgr, int32 *flg);
+extern int32 op_emodg (int32 *opnd, int32 *rh, int32 *intgr, int32 *flg);
+extern int32 op_movfd (int32 val);
+extern int32 op_mnegfd (int32 val);
+extern int32 op_movg (int32 val);
+extern int32 op_mnegg (int32 val);
+extern int32 op_cvtdf (int32 *opnd);
+extern int32 op_cvtfg (int32 *opnd, int32 *rh);
+extern int32 op_cvtgf (int32 *opnd);
+extern int32 op_addf (int32 *opnd, t_bool sub);
+extern int32 op_addd (int32 *opnd, int32 *rh, t_bool sub);
+extern int32 op_addg (int32 *opnd, int32 *rh, t_bool sub);
+extern int32 op_mulf (int32 *opnd);
+extern int32 op_muld (int32 *opnd, int32 *rh);
+extern int32 op_mulg (int32 *opnd, int32 *rh);
+extern int32 op_divf (int32 *opnd);
+extern int32 op_divd (int32 *opnd, int32 *rh);
+extern int32 op_divg (int32 *opnd, int32 *rh);
+extern void op_polyf (int32 *opnd, int32 acc);
+extern void op_polyd (int32 *opnd, int32 acc);
+extern void op_polyg (int32 *opnd, int32 acc);
+
+/* vax_octa.c externals */
+extern int32 op_octa (int32 *opnd, int32 cc, int32 opc, int32 acc, int32 spec, int32 va);
+
+/* vax_cmode.c externals */
+extern int32 op_cmode (int32 cc);
+extern int32 BadCmPSL (int32 newpsl);
+
+/* vax_sys.c externals */
+extern const uint16 drom[NUM_INST][MAX_SPEC + 1];
+
 /* Model dependent definitions */
+extern int32 eval_int (void);
+extern int32 machine_check (int32 p1, int32 opc, int32 cc, int32 delta);
+extern int32 get_vector (int32 lvl);
+extern int32 con_halt (int32 code, int32 cc);
+extern t_stat cpu_boot (int32 unitno, DEVICE *dptr);
+extern t_stat build_dib_tab (void);
+extern void rom_wr_B (int32 pa, int32 val);
 
 #if defined (VAX_780)
 #include "vax780_defs.h"
diff --git a/VAX/vax_fpa.c b/VAX/vax_fpa.c
index 1b15c179..f183e782 100644
--- a/VAX/vax_fpa.c
+++ b/VAX/vax_fpa.c
@@ -59,11 +59,6 @@
 #include "vax_defs.h"
 #include <setjmp.h>
 
-extern int32 R[16];
-extern int32 PSL;
-extern int32 p1;
-extern jmp_buf save_env;
-
 #if defined (USE_INT64)
 
 #define M64             0xFFFFFFFFFFFFFFFF              /* 64b */
diff --git a/VAX/vax_io.c b/VAX/vax_io.c
index 5f5d3366..68b225a4 100644
--- a/VAX/vax_io.c
+++ b/VAX/vax_io.c
@@ -115,12 +115,7 @@ int32 cq_mbr = 0;                                       /* MBR */
 int32 cq_ipc = 0;                                       /* IPC */
 int32 autcon_enb = 1;                                   /* autoconfig enable */
 
-extern uint32 *M;
-extern UNIT cpu_unit;
-extern int32 PSL, SISR, trpirq, mem_err, crd_err, hlt_pin;
-extern int32 p1;
 extern int32 ssc_bto;
-extern jmp_buf save_env;
 extern int32 vc_mem_rd (int32 pa);
 extern void vc_mem_wr (int32 pa, int32 val, int32 lnt);
 extern uint32 *vc_buf;
diff --git a/VAX/vax_mmu.c b/VAX/vax_mmu.c
index 5cb62db3..debc2936 100644
--- a/VAX/vax_mmu.c
+++ b/VAX/vax_mmu.c
@@ -53,16 +53,6 @@
 #include "vax_mmu.h"
 #include <setjmp.h>
 
-extern uint32 *M;
-extern int32 PSL;
-extern int32 mapen;
-extern int32 p1, p2;
-extern int32 P0BR, P0LR;
-extern int32 P1BR, P1LR;
-extern int32 SBR, SLR;
-extern int32 SISR;
-extern jmp_buf save_env;
-
 int32 d_p0br, d_p0lr;                                   /* dynamic copies */
 int32 d_p1br, d_p1lr;                                   /* altered per ucode */
 int32 d_sbr, d_slr;
@@ -219,7 +209,7 @@ return stlb[tbi];
 
 /* Utility routines */
 
-extern void set_map_reg (void)
+void set_map_reg (void)
 {
 d_p0br = P0BR & ~03;
 d_p1br = (P1BR - 0x800000) & ~03;                       /* VA<30> >> 7 */
@@ -227,7 +217,6 @@ d_sbr = (SBR - 0x1000000) & ~03;                        /* VA<31> >> 7 */
 d_p0lr = (P0LR << 2);
 d_p1lr = (P1LR << 2) + 0x800000;                        /* VA<30> >> 7 */
 d_slr = (SLR << 2) + 0x1000000;                         /* VA<31> >> 7 */
-return;
 }
 
 /* Zap process (0) or whole (1) tb */
@@ -241,7 +230,6 @@ for (i = 0; i < VA_TBSIZE; i++) {
     if (stb)
         stlb[i].tag = stlb[i].pte = -1;
     }
-return;
 }
 
 /* Zap single tb entry corresponding to va */
@@ -253,7 +241,6 @@ int32 tbi = VA_GETTBI (VA_GETVPN (va));
 if (va & VA_S0)
     stlb[tbi].tag = stlb[tbi].pte = -1;
 else ptlb[tbi].tag = ptlb[tbi].pte = -1;
-return;
 }
 
 /* Check for tlb entry corresponding to va */
diff --git a/VAX/vax_mmu.h b/VAX/vax_mmu.h
index 5122b84b..25e7051d 100644
--- a/VAX/vax_mmu.h
+++ b/VAX/vax_mmu.h
@@ -57,8 +57,9 @@ typedef struct {
     } TLBENT;
 
 extern uint32 *M;
-extern int32 mapen;
+extern int32 mapen;                                     /* map enable */
 extern UNIT cpu_unit;
+extern DEVICE cpu_dev;
 
 extern int32 mchk_va, mchk_ref;                         /* for mcheck */
 extern TLBENT stlb[VA_TBSIZE], ptlb[VA_TBSIZE];
@@ -67,6 +68,10 @@ static const int32 insert[4] = {
     0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF
     };
 
+extern void zap_tb (int stb);
+extern void zap_tb_ent (uint32 va);
+extern t_bool chk_tb_ent (uint32 va);
+extern void set_map_reg (void);
 extern int32 ReadIO (uint32 pa, int32 lnt);
 extern void WriteIO (uint32 pa, int32 val, int32 lnt);
 extern int32 ReadReg (uint32 pa, int32 lnt);
diff --git a/VAX/vax_octa.c b/VAX/vax_octa.c
index c46b2718..682b9352 100644
--- a/VAX/vax_octa.c
+++ b/VAX/vax_octa.c
@@ -48,14 +48,6 @@
 
 #if defined (FULL_VAX)
 
-extern int32 R[16];
-extern int32 PSL;
-extern int32 trpirq;
-extern int32 p1;
-extern jmp_buf save_env;
-
-extern int32 Test (uint32 va, int32 acc, int32 *status);
-
 #define WORDSWAP(x)     ((((x) & WMASK) << 16) | (((x) >> 16) & WMASK))
 
 typedef struct {
@@ -1251,8 +1243,6 @@ return;
 
 #else
 
-extern jmp_buf save_env;
-
 int32 op_octa (int32 *opnd, int32 cc, int32 opc, int32 acc, int32 spec, int32 va)
 {
 RSVD_INST_FAULT;
diff --git a/VAX/vax_stddev.c b/VAX/vax_stddev.c
index a69de74c..ba626a65 100644
--- a/VAX/vax_stddev.c
+++ b/VAX/vax_stddev.c
@@ -93,9 +93,6 @@
 #define CLK_DELAY       5000                            /* 100 Hz */
 #define TMXR_MULT       1                               /* 100 Hz */
 
-extern int32 int_req[IPL_HLVL];
-extern int32 hlt_pin;
-
 int32 tti_csr = 0;                                      /* control/status */
 uint32 tti_buftime;                                     /* time input character arrived */
 int32 tto_csr = 0;                                      /* control/status */
diff --git a/VAX/vax_sys.c b/VAX/vax_sys.c
index 8eb9496d..d9bb4910 100644
--- a/VAX/vax_sys.c
+++ b/VAX/vax_sys.c
@@ -53,10 +53,7 @@
 #define ODC(x)          ((x) << DR_V_USPMASK)
 #endif
 
-extern UNIT cpu_unit;
 extern REG cpu_reg[];
-extern int32 saved_PC;
-extern int32 PSL;
 
 t_stat fprint_sym_m (FILE *of, uint32 addr, t_value *val);
 int32 fprint_sym_qoimm (FILE *of, t_value *val, int32 vp, int32 lnt);
diff --git a/VAX/vax_syscm.c b/VAX/vax_syscm.c
index b4242901..7cbb8d28 100644
--- a/VAX/vax_syscm.c
+++ b/VAX/vax_syscm.c
@@ -32,7 +32,6 @@
 */
 
 #include "vax_defs.h"
-#include <ctype.h>
 
 /* Symbol tables */
 /* Warning: for literals, the class number MUST equal the field width!! */
diff --git a/VAX/vax_sysdev.c b/VAX/vax_sysdev.c
index bcf99b3f..7a886625 100644
--- a/VAX/vax_sysdev.c
+++ b/VAX/vax_sysdev.c
@@ -189,22 +189,7 @@ CTAB vax_cmd[] = {
 
 #define SSCADS_MASK     0x3FFFFFFC                      /* match or mask */
 
-extern int32 R[16];
-extern int32 STK[5];
-extern int32 PSL;
-extern int32 SISR;
-extern int32 mapen;
-extern int32 pcq[PCQ_SIZE];
-extern int32 pcq_p;
-extern int32 ibcnt, ppc;
-extern int32 in_ie;
-extern int32 mchk_va, mchk_ref;
-extern int32 fault_PC;
-extern int32 int_req[IPL_HLVL];
-extern UNIT cpu_unit;
 extern UNIT clk_unit;
-extern jmp_buf save_env;
-extern int32 p1;
 extern int32 MSER;
 extern int32 tmr_poll;
 extern DEVICE vc_dev, lk_dev, vs_dev;
diff --git a/VAX/vax_syslist.c b/VAX/vax_syslist.c
index 52e15094..8759b347 100644
--- a/VAX/vax_syslist.c
+++ b/VAX/vax_syslist.c
@@ -62,8 +62,6 @@ extern DEVICE vc_dev;
 extern DEVICE lk_dev;
 extern DEVICE vs_dev;
 
-extern void WriteB (uint32 pa, int32 val);
-extern void rom_wr_B (int32 pa, int32 val);
 extern UNIT cpu_unit;
 
 DEVICE *sim_devices[] = { 
diff --git a/VAX/vax_vc.c b/VAX/vax_vc.c
index d5f37be0..e7d8359c 100644
--- a/VAX/vax_vc.c
+++ b/VAX/vax_vc.c
@@ -193,7 +193,6 @@ BITFIELD vc_ic_mode_bits[] = {
 
 #define IOLN_QVSS       0100
 
-extern int32 int_req[IPL_HLVL];
 extern int32 tmxr_poll;                                 /* calibrated delay */
 
 extern t_stat lk_wr (uint8 c);
@@ -666,9 +665,6 @@ switch (rg) {
 return SCPE_OK;
 }
 
-extern jmp_buf save_env;
-extern int32 p1;
-
 int32 vc_mem_rd (int32 pa)
 {
 uint32 rg = (pa >> 2) & 0xFFFF;
diff --git a/VAX/vaxmod_defs.h b/VAX/vaxmod_defs.h
index 82473f24..2b1bb13e 100644
--- a/VAX/vaxmod_defs.h
+++ b/VAX/vaxmod_defs.h
@@ -431,6 +431,7 @@ typedef struct {
 #define SET_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] | (INT_##dv)
 #define CLR_INT(dv)     int_req[IPL_##dv] = int_req[IPL_##dv] & ~(INT_##dv)
 #define IORETURN(f,v)   ((f)? (v): SCPE_OK)             /* cond error return */
+extern int32 int_req[IPL_HLVL];                         /* intr, IPL 14-17 */
 
 /* Logging */