From 0f32d9fca9ee58127461ac72b2669318c20156f7 Mon Sep 17 00:00:00 2001
From: outofmbufs <neil@webber.com>
Date: Wed, 9 Apr 2025 22:16:56 -0500
Subject: [PATCH 1/2] Make @property psw use pswfields/dict methods

---
 machine.py | 30 ++++++++----------------------
 1 file changed, 8 insertions(+), 22 deletions(-)

diff --git a/machine.py b/machine.py
index 492fce6..fff042c 100644
--- a/machine.py
+++ b/machine.py
@@ -921,28 +921,14 @@ class PDP1170(PDP11):
 
     @property
     def psw(self):
-        # NOTE: to simplify/accelerate condition code handling during
-        # instructions, the NZVC bits are broken out into individual
-        # attributes, and are stored as truthy/falsey not necessarily
-        # 1/0 or True/False.
-
-        # so, to reconstitute NZVC bits ...
-        NZVC = 0
-        if self.psw_n:
-            NZVC |= 0o10
-        if self.psw_z:
-            NZVC |= 0o04
-        if self.psw_v:
-            NZVC |= 0o02
-        if self.psw_c:
-            NZVC |= 0o01
-
-        return (((self.psw_curmode & 3) << 14) |
-                ((self.psw_prevmode & 3) << 12) |
-                ((self.psw_regset & 1) << 11) |
-                ((self.psw_pri & 7) << 5) |
-                ((self.psw_trap & 1) << 4) |
-                NZVC)
+        pswd = {attr: getattr(self, 'psw_' + attr)
+                for attr in self._pswfields}
+        # the various 1-bit attributes are stored as "truthy/falsy"
+        # in the psw_foo attributes but need to be normalized to 1/0 here
+        for a, v in pswd.items():
+            if self._pswfields[a][1] == 1:
+                pswd[a] = bool(v)
+        return self._dict2psw(pswd)
 
     # Write the ENTIRE processor word, without any privilege enforcement.
     # The lack of privilege enforcement is necessary because, e.g., that's

From 0ad6fec19b6f3615d8d6fb9b8299bca9bea967a7 Mon Sep 17 00:00:00 2001
From: outofmbufs <neil@webber.com>
Date: Thu, 10 Apr 2025 12:44:25 -0500
Subject: [PATCH 2/2] test_psw

---
 pdptests.py | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/pdptests.py b/pdptests.py
index 9753e96..03c886d 100644
--- a/pdptests.py
+++ b/pdptests.py
@@ -356,6 +356,69 @@ class TestMethods(unittest.TestCase):
                 self.check16(p)
                 self.assertEqual(p.r[0], r0result)
 
+    def test_psw(self):
+        p = self.make_pdp()
+
+        # the test is assembled from:
+        #         .org 4000
+        #         halt = 0
+        #         mov $20000,sp   / establish a stack on general principles
+        #         clr r0               / clears all PSW bits except Z
+        #         inc r0               / clears Z
+        #         sen
+        #         bmi 1f
+        #         mov $66610,r2
+        #         halt
+        # 1:      cln
+        #         bpl 1f
+        #         mov $66650,r2
+        #         halt
+        # 1:      clr r0
+        #         inc r0
+        #         sez
+        #         beq 1f
+        #         mov $66604,r2
+        #         halt
+        # 1:      clz
+        #         bne 1f
+        #         mov $66644,r2
+        #         halt
+        # 1:      clr r0
+        #         inc r0
+        #         sev
+        #         bvs 1f
+        #         mov $66602,r2
+        #         halt
+        # 1:      clv
+        #         bvc 1f
+        #         mov $66642,r2
+        #         halt
+        # 1:      clr r0
+        #         inc r0
+        #         sec
+        #         bcs 1f
+        #         mov $66601,r2
+        #         halt
+        # 1:      clc
+        #         bcc 1f
+        #         mov $66641,r2
+        #         halt
+        # 1:      mov $77, r2
+        #         halt
+
+        insts = [0o12706, 0o20000, 0o5000, 0o5200, 0o270, 0o100403, 0o12702,
+                 0o66610, 0o0, 0o250, 0o100003, 0o12702, 0o66650, 0o0,
+                 0o5000, 0o5200, 0o264, 0o1403, 0o12702, 0o66604, 0o0,
+                 0o244, 0o1003, 0o12702, 0o66644, 0o0, 0o5000, 0o5200, 0o262,
+                 0o102403, 0o12702, 0o66602, 0o0, 0o242, 0o102003, 0o12702,
+                 0o66642, 0o0, 0o5000, 0o5200, 0o261, 0o103403, 0o12702,
+                 0o66601, 0o0, 0o241, 0o103003, 0o12702, 0o66641, 0o0,
+                 0o12702, 0o77, 0o0]
+
+        self.loadphysmem(p, insts, 0o4000)
+        p.run(pc=0o4000)
+        self.assertEqual(p.r[2], 0o77)
+
     def test_add_sub(self):
         p = self.make_pdp()