Research V6 development

[unix-history] / usr / sys / reg.h

diff --git a/usr/sys/reg.h b/usr/sys/reg.h
index ce330b8..71f1b5f 100644 (file)
--- a/usr/sys/reg.h
+++ b/usr/sys/reg.h
@@ -1,3 +1,8 @@
+/*
+ * Location of the users' stored
+ * registers relative to R0.
+ * Usage is u.u_ar0[XX].
+ */

 #define        R0      (0)
 #define        R1      (-2)
 #define        R2      (-9)
 #define        R0      (0)
 #define        R1      (-2)
 #define        R2      (-9)


@@ -7,3 +12,5 @@
 #define        R6      (-3)
 #define        R7      (1)
 #define        RPS     (2)
 #define        R6      (-3)
 #define        R7      (1)
 #define        RPS     (2)

+
+#define        TBIT    020             /* PS trace bit */