diff --git a/scheme/ikarus.boot.4.prebuilt b/scheme/ikarus.boot.4.prebuilt
index 2172bc5..d269109 100644
Binary files a/scheme/ikarus.boot.4.prebuilt and b/scheme/ikarus.boot.4.prebuilt differ
diff --git a/scheme/ikarus.boot.8.prebuilt b/scheme/ikarus.boot.8.prebuilt
index 90ff0bf..052eead 100644
Binary files a/scheme/ikarus.boot.8.prebuilt and b/scheme/ikarus.boot.8.prebuilt differ
diff --git a/scheme/ikarus.main.ss b/scheme/ikarus.main.ss
index de7addd..3ae5454 100644
--- a/scheme/ikarus.main.ss
+++ b/scheme/ikarus.main.ss
@@ -72,7 +72,7 @@
 (library (ikarus main)
   (export)
   (import (ikarus)
-          (ikarus startup)
+          (except (ikarus startup) host-info)
           (only (ikarus load) load-r6rs-top-level))
   (init-library-path)
   (let-values ([(files script script-type args)
diff --git a/scheme/ikarus.writer.ss b/scheme/ikarus.writer.ss
index 33ef19f..8156d33 100644
--- a/scheme/ikarus.writer.ss
+++ b/scheme/ikarus.writer.ss
@@ -27,6 +27,7 @@
     (ikarus system $symbols)
     (ikarus system $bytevectors)
     (ikarus system $transcoders)
+    (only (ikarus system $foreign) pointer? pointer->integer)
     (only (ikarus.pretty-formats) get-fmt)
     (except (ikarus) 
       write display format printf fprintf print-error print-unicode print-graph
diff --git a/scheme/last-revision b/scheme/last-revision
index ff0ba09..fed8f61 100644
--- a/scheme/last-revision
+++ b/scheme/last-revision
@@ -1 +1 @@
-1621
+1622
diff --git a/scheme/makefile.ss b/scheme/makefile.ss
index 8a69fbe..c2087f4 100755
--- a/scheme/makefile.ss
+++ b/scheme/makefile.ss
@@ -271,7 +271,7 @@
     [$stack      (ikarus system $stack)                #f     #t]
     [$interrupts (ikarus system $interrupts)           #f     #t]
     [$io         (ikarus system $io)                   #f     #t]
-    [$for        (ikarus system $foreign)              #f     #f]
+    [$for        (ikarus system $foreign)              #f     #t]
     [$all        (psyntax system $all)                 #f     #t]
     [$boot       (psyntax system $bootstrap)           #f     #t]
     [ne          (psyntax null-environment-5)          #f     #f]
@@ -1484,7 +1484,7 @@
     [pointer-ref-double         $for]
     [make-callout               $for]
     [make-callback              $for]
-    [host-info            i]
+    [host-info                     i]
 
   ))
 
diff --git a/scheme/pass-specify-rep-primops.ss b/scheme/pass-specify-rep-primops.ss
index fc838f4..222675e 100644
--- a/scheme/pass-specify-rep-primops.ss
+++ b/scheme/pass-specify-rep-primops.ss
@@ -233,7 +233,8 @@
       (cond
         [(list? ls) (nop)]
         [else (interrupt)])]
-     [(known) (error 'translate "memq")]
+     [(known expr t)
+      (cogen-effect-memq x expr)]
      [else (interrupt)])])
 
 (define (equable? x)
@@ -247,7 +248,8 @@
         [(and (list? lsv) (andmap equable? lsv))
          (cogen-value-$memq x ls)]
         [else (interrupt)])]
-     [(known) (error 'translate "memv")]
+     [(known expr t)
+      (cogen-value-memv x expr)]
      [else (interrupt)])]
   [(P x ls) 
    (struct-case ls
@@ -256,7 +258,8 @@
         [(and (list? lsv) (andmap equable? lsv))
          (cogen-pred-$memq x ls)]
         [else (interrupt)])]
-     [(known) (error 'translate "memv")]
+     [(known expr t)
+      (cogen-pred-memv x expr)]
      [else (interrupt)])]
   [(E x ls)
    (struct-case ls
@@ -264,7 +267,8 @@
       (cond
         [(list? lsv) (nop)]
         [else (interrupt)])]
-     [(known) (error 'translate "memv")]
+     [(known expr t)
+      (cogen-effect-memv x expr)]
      [else (interrupt)])])
 
 /section)
@@ -639,7 +643,8 @@
       (prm 'mref (T x)
          (K (+ (- disp-closure-data closure-tag)
                (* i wordsize))))]
-     [(known) (error 'translate "$cpref")]
+     [(known expr t)
+      (cogen-value-$cpref x expr)]
      [else (interrupt)])])
 
 /section)
@@ -717,7 +722,8 @@
             (interrupt-when (cogen-pred-$unbound-object? v))
             v)
           (interrupt))]
-     [(known) (error 'translate "top-level-value")]
+     [(known expr t)
+      (cogen-value-top-level-value expr)]
      [else
       (with-tmp ([x (T x)])
         (interrupt-unless (cogen-pred-symbol? x))
@@ -731,7 +737,8 @@
           (with-tmp ([v (cogen-value-$symbol-value x)])
             (interrupt-when (cogen-pred-$unbound-object? v)))
           (interrupt))]
-     [(known) (error 'translate "top-level-value")]
+     [(known expr t)
+      (cogen-effect-top-level-value expr)]
      [else
       (with-tmp ([x (T x)])
         (interrupt-unless (cogen-pred-symbol? x))
@@ -1047,7 +1054,8 @@
              (K (+ (- 7 i) (- disp-flonum-data record-tag))))
            (K 255))
         (K fx-shift))]
-     [(known) (error 'translate "$flonum-u8-ref")]
+     [(known expr t) 
+      (cogen-value-$flonum-u8-ref s expr)]
      [else (interrupt)])]
   [(P s i) (K #t)]
   [(E s i) (nop)])
@@ -1070,7 +1078,8 @@
          (T x)
          (K (+ (- 7 i) (- disp-flonum-data vector-tag)))
          (prm 'sra (T v) (K fx-shift)))]
-     [(known) (error 'translate "$flonum-set!")]
+     [(known expr t) 
+      (cogen-effect-$flonum-set! x expr v)]
      [else (interrupt)])])
 
 (define-primop $fixnum->flonum unsafe
@@ -1605,7 +1614,8 @@
                (K fx-shift))))]
         [else
          (interrupt)])]
-     [(known) (error 'translate "div")]
+     [(known expr t)
+      (cogen-value-div x expr)]
      [else (interrupt)])])
 
 (define-primop quotient safe