diff --git a/SheepShaver/src/Unix/main_unix.cpp b/SheepShaver/src/Unix/main_unix.cpp
index f1b1c4ca..5fdecce9 100644
--- a/SheepShaver/src/Unix/main_unix.cpp
+++ b/SheepShaver/src/Unix/main_unix.cpp
@@ -109,6 +109,7 @@
 #include "user_strings.h"
 #include "vm_alloc.h"
 #include "sigsegv.h"
+#include "sigregs.h"
 
 #define DEBUG 0
 #include "debug.h"
@@ -167,94 +168,6 @@ const uintptr RAM_BASE = 0x10000000;		// Base address of RAM
 const uint32 SIG_STACK_SIZE = 0x10000;		// Size of signal stack
 
 
-#if !EMULATED_PPC
-struct sigregs {
-	uint32 nip;
-	uint32 link;
-	uint32 ctr;
-	uint32 msr;
-	uint32 xer;
-	uint32 ccr;
-	uint32 gpr[32];
-};
-
-#if defined(__linux__)
-#include <sys/ucontext.h>
-#define MACHINE_REGISTERS(scp)	((machine_regs *)(((ucontext_t *)scp)->uc_mcontext.regs))
-
-struct machine_regs : public pt_regs
-{
-	u_long & cr()				{ return pt_regs::ccr; }
-	uint32 cr() const			{ return pt_regs::ccr; }
-	uint32 lr() const			{ return pt_regs::link; }
-	uint32 ctr() const			{ return pt_regs::ctr; }
-	uint32 xer() const			{ return pt_regs::xer; }
-	uint32 msr() const			{ return pt_regs::msr; }
-	uint32 dar() const			{ return pt_regs::dar; }
-	u_long & pc()				{ return pt_regs::nip; }
-	uint32 pc() const			{ return pt_regs::nip; }
-	u_long & gpr(int i)			{ return pt_regs::gpr[i]; }
-	uint32 gpr(int i) const		{ return pt_regs::gpr[i]; }
-};
-#endif
-
-#if defined(__NetBSD__)
-#include <sys/ucontext.h>
-#define MACHINE_REGISTERS(scp)	((machine_regs *)&(((ucontext_t *)scp)->uc_mcontext))
-
-struct machine_regs : public mcontext_t
-{
-	long & cr()					{ return __gregs[_REG_CR]; }
-	uint32 cr() const			{ return __gregs[_REG_CR]; }
-	uint32 lr() const			{ return __gregs[_REG_LR]; }
-	uint32 ctr() const			{ return __gregs[_REG_CTR]; }
-	uint32 xer() const			{ return __gregs[_REG_XER]; }
-	uint32 msr() const			{ return __gregs[_REG_MSR]; }
-	uint32 dar() const			{ return (uint32)(((siginfo_t *)(((unsigned long)this) - offsetof(ucontext_t, uc_mcontext))) - 1)->si_addr; } /* HACK */
-	long & pc()					{ return __gregs[_REG_PC]; }
-	uint32 pc() const			{ return __gregs[_REG_PC]; }
-	long & gpr(int i)			{ return __gregs[_REG_R0 + i]; }
-	uint32 gpr(int i) const		{ return __gregs[_REG_R0 + i]; }
-};
-#endif
-
-#if defined(__APPLE__) && defined(__MACH__)
-#include <sys/signal.h>
-extern "C" int sigaltstack(const struct sigaltstack *ss, struct sigaltstack *oss);
-
-#include <sys/ucontext.h>
-#define MACHINE_REGISTERS(scp)	((machine_regs *)(((ucontext_t *)scp)->uc_mcontext))
-
-struct machine_regs : public mcontext
-{
-	uint32 & cr()				{ return ss.cr; }
-	uint32 cr() const			{ return ss.cr; }
-	uint32 lr() const			{ return ss.lr; }
-	uint32 ctr() const			{ return ss.ctr; }
-	uint32 xer() const			{ return ss.xer; }
-	uint32 msr() const			{ return ss.srr1; }
-	uint32 dar() const			{ return es.dar; }
-	uint32 & pc()				{ return ss.srr0; }
-	uint32 pc() const			{ return ss.srr0; }
-	uint32 & gpr(int i)			{ return (&ss.r0)[i]; }
-	uint32 gpr(int i) const		{ return (&ss.r0)[i]; }
-};
-#endif
-
-static void build_sigregs(sigregs *srp, machine_regs *mrp)
-{
-	srp->nip = mrp->pc();
-	srp->link = mrp->lr();
-	srp->ctr = mrp->ctr();
-	srp->msr = mrp->msr();
-	srp->xer = mrp->xer();
-	srp->ccr = mrp->cr();
-	for (int i = 0; i < 32; i++)
-		srp->gpr[i] = mrp->gpr(i);
-}
-#endif
-
-
 // Global variables (exported)
 #if !EMULATED_PPC
 void *TOC = NULL;		// Pointer to Thread Local Storage (r2)
diff --git a/SheepShaver/src/Unix/sigregs.h b/SheepShaver/src/Unix/sigregs.h
new file mode 100644
index 00000000..294901e7
--- /dev/null
+++ b/SheepShaver/src/Unix/sigregs.h
@@ -0,0 +1,118 @@
+/*
+ *  sigregs.h - Extract machine registers from a signal frame
+ *
+ *  SheepShaver (C) 1997-2005 Christian Bauer and Marc Hellwig
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef SIGREGS_H
+#define SIGREGS_H
+
+#ifndef EMULATED_PPC
+
+// Common representation of machine registers
+struct sigregs {
+	uint32 nip;
+	uint32 link;
+	uint32 ctr;
+	uint32 msr;
+	uint32 xer;
+	uint32 ccr;
+	uint32 gpr[32];
+};
+
+// Extract machine registers from Linux signal frame
+#if defined(__linux__)
+#include <sys/ucontext.h>
+#define MACHINE_REGISTERS(scp)	((machine_regs *)(((ucontext_t *)scp)->uc_mcontext.regs))
+
+struct machine_regs : public pt_regs
+{
+	u_long & cr()				{ return pt_regs::ccr; }
+	uint32 cr() const			{ return pt_regs::ccr; }
+	uint32 lr() const			{ return pt_regs::link; }
+	uint32 ctr() const			{ return pt_regs::ctr; }
+	uint32 xer() const			{ return pt_regs::xer; }
+	uint32 msr() const			{ return pt_regs::msr; }
+	uint32 dar() const			{ return pt_regs::dar; }
+	u_long & pc()				{ return pt_regs::nip; }
+	uint32 pc() const			{ return pt_regs::nip; }
+	u_long & gpr(int i)			{ return pt_regs::gpr[i]; }
+	uint32 gpr(int i) const		{ return pt_regs::gpr[i]; }
+};
+#endif
+
+// Extract machine registers from NetBSD signal frame
+#if defined(__NetBSD__)
+#include <sys/ucontext.h>
+#define MACHINE_REGISTERS(scp)	((machine_regs *)&(((ucontext_t *)scp)->uc_mcontext))
+
+struct machine_regs : public mcontext_t
+{
+	long & cr()					{ return __gregs[_REG_CR]; }
+	uint32 cr() const			{ return __gregs[_REG_CR]; }
+	uint32 lr() const			{ return __gregs[_REG_LR]; }
+	uint32 ctr() const			{ return __gregs[_REG_CTR]; }
+	uint32 xer() const			{ return __gregs[_REG_XER]; }
+	uint32 msr() const			{ return __gregs[_REG_MSR]; }
+	uint32 dar() const			{ return (uint32)(((siginfo_t *)(((unsigned long)this) - offsetof(ucontext_t, uc_mcontext))) - 1)->si_addr; } /* HACK */
+	long & pc()					{ return __gregs[_REG_PC]; }
+	uint32 pc() const			{ return __gregs[_REG_PC]; }
+	long & gpr(int i)			{ return __gregs[_REG_R0 + i]; }
+	uint32 gpr(int i) const		{ return __gregs[_REG_R0 + i]; }
+};
+#endif
+
+// Extract machine registers from Darwin signal frame
+#if defined(__APPLE__) && defined(__MACH__)
+#include <sys/signal.h>
+extern "C" int sigaltstack(const struct sigaltstack *ss, struct sigaltstack *oss);
+
+#include <sys/ucontext.h>
+#define MACHINE_REGISTERS(scp)	((machine_regs *)(((ucontext_t *)scp)->uc_mcontext))
+
+struct machine_regs : public mcontext
+{
+	uint32 & cr()				{ return ss.cr; }
+	uint32 cr() const			{ return ss.cr; }
+	uint32 lr() const			{ return ss.lr; }
+	uint32 ctr() const			{ return ss.ctr; }
+	uint32 xer() const			{ return ss.xer; }
+	uint32 msr() const			{ return ss.srr1; }
+	uint32 dar() const			{ return es.dar; }
+	uint32 & pc()				{ return ss.srr0; }
+	uint32 pc() const			{ return ss.srr0; }
+	uint32 & gpr(int i)			{ return (&ss.r0)[i]; }
+	uint32 gpr(int i) const		{ return (&ss.r0)[i]; }
+};
+#endif
+
+// Convert system-dependent machine registers to generic sigregs
+static void build_sigregs(sigregs *srp, machine_regs *mrp)
+{
+	srp->nip = mrp->pc();
+	srp->link = mrp->lr();
+	srp->ctr = mrp->ctr();
+	srp->msr = mrp->msr();
+	srp->xer = mrp->xer();
+	srp->ccr = mrp->cr();
+	for (int i = 0; i < 32; i++)
+		srp->gpr[i] = mrp->gpr(i);
+}
+
+#endif
+
+#endif /* SIGREGS_H */