Add BACKGROUND-YIELD to Lisp.sysout (and thus to FULL.SYSOUT) so you don't need to load it in INITs.

internal/loadups/LOADUP-LISP

@@ -1,12 +1,13 @@
 (DEFINE-FILE-INFO PACKAGE "INTERLISP" READTABLE "XCL" BASE 10)
 
-
(FILECREATED "16-Oct-2025 16:55:27" |{WMEDLEY}<internal>loadups>LOADUP-LISP.;22|
 7104   
+
(FILECREATED " 5-Nov-2025 09:04:36" |{DSK}<Users>larry>il>MEDLEY>INTERNAL>loadups>LOADUP-LISP.;2|
 7333   
 
-      :EDIT-BY |rmk|
+      :EDIT-BY "lmm"
 
       :CHANGES-TO (FNS LOADUP-LISP)
 
-      :PREVIOUS-DATE "18-Aug-2025 12:09:49" |{WMEDLEY}<internal>loadups>LOADUP-LISP.;21|)
+      :PREVIOUS-DATE "16-Oct-2025 16:55:27" 
+|{DSK}<Users>larry>il>MEDLEY>INTERNAL>loadups>LOADUP-LISP.;1|)
 
 
 (PRETTYCOMPRINT LOADUP-LISPCOMS)
@@ -19,7 +20,8 @@
 (DEFINEQ
 
 (LOADUP-LISP

-  (LAMBDA (DRIBBLEFILE)
                                     (* \; "Edited 16-Oct-2025 16:55 by rmk")


+  (LAMBDA (DRIBBLEFILE)
                                     (* \; "Edited  5-Nov-2025 09:01 by lmm")


+                                                            (* \; "Edited 16-Oct-2025 16:55 by rmk")


                                                             (* \; "Edited 18-Aug-2025 12:08 by rmk")


                                                             (* \; "Edited 15-Jun-2025 14:39 by rmk")


                                                             (* \; "Edited 24-May-2025 10:20 by rmk")


@@ -126,7 +128,10 @@
 
     (* |;;| " Added late, LOAD late to avoid any dependencies")

 
+    (* |;;| "prevent medley from pinning CPU")

+
     (LOADUP '(XCL-LOOP XCL-HASH-LOOP))
+    (LOADUP '(BACKGROUND-YIELD))
 
     (* |;;| " networking code -- should make it optional but too many cross dependencies")

 
@@ -144,5 +149,5 @@
 (GLOBALVARS MAKESYSFILENAME MEDLEY-INIT-VARS MEDLEYDIR SYSTEMINITVARS USERRECLST)
 )
 (DECLARE\: DONTCOPY
-  (FILEMAP (NIL (640 6898 (LOADUP-LISP 650 . 6896)))))
+  (FILEMAP (NIL (675 7127 (LOADUP-LISP 685 . 7125)))))
 STOP

lispusers/BACKGROUND-YIELD

@@ -1,12 +1,12 @@
 (DEFINE-FILE-INFO PACKAGE "INTERLISP" READTABLE "INTERLISP" BASE 10)
 
-
(FILECREATED "28-Jul-2023 09:49:24" {DSK}<home>larry>il>medley>lispusers>BACKGROUND-YIELD.;2
 1770   
+
(FILECREATED " 9-Nov-2025 11:52:07" {DSK}<Users>larry>il>MEDLEY>LISPUSERS>BACKGROUND-YIELD.;2
 1882   
 
       :EDIT-BY "lmm"
 
       :CHANGES-TO (FNS BACKGROUND-YIELD)
 
-      :PREVIOUS-DATE "14-Nov-2021 22:05:58" {DSK}<home>larry>il>medley>lispusers>BACKGROUND-YIELD.;1
+      :PREVIOUS-DATE "28-Jul-2023 09:49:24" {DSK}<Users>larry>il>MEDLEY>LISPUSERS>BACKGROUND-YIELD.;1
 )
 
 
@@ -26,13 +26,14 @@
 (DEFINEQ
 
 (BACKGROUND-YIELD

-  [LAMBDA NIL
                                                (* ; "Edited 28-Jul-2023 09:11 by lmm")


+  [LAMBDA NIL
                                                (* ; "Edited  9-Nov-2025 11:50 by lmm")


+                                                             (* ; "Edited 28-Jul-2023 09:11 by lmm")


                                                            (* ; "Edited 20-Sep-2021 11:37 by larry")

     (LET ((\BACKGROUND T))
-         (DECLARE
 (SPECVARS \BACKGROUND))
+         (DECLARE
 (SPECVARS \BACKGROUND)
+                (GLOBALVARS BACKGROUND-YIELD))
          (IF
 (FIXP BACKGROUND-YIELD)
-             THEN
 (SUBRCALL YIELD BACKGROUND-YIELD)
-                  (SUBRCALL CAUSE-INTERRUPT])
+             THEN
 (SUBRCALL YIELD BACKGROUND-YIELD])
 
 (INIT-YIELD

   [LAMBDA (ONP)
                                        (* ; "Edited 19-Sep-2021 13:32 by larry")

@@ -51,5 +52,5 @@
 
 (RPAQQ BACKGROUND-YIELD
 833333)
 (DECLARE%: DONTCOPY
-  (FILEMAP (NIL (806 1655 (BACKGROUND-YIELD 816 . 1271) (INIT-YIELD 1273 . 1653)))))
+  (FILEMAP (NIL (808 1767 (BACKGROUND-YIELD 818 . 1383) (INIT-YIELD 1385 . 1765)))))
 STOP