diff --git a/scheme/ikarus.compiler.altcogen.ss b/scheme/ikarus.compiler.altcogen.ss
index 168671a..33b3920 100644
--- a/scheme/ikarus.compiler.altcogen.ss
+++ b/scheme/ikarus.compiler.altcogen.ss
@@ -2453,6 +2453,7 @@
                    `(int ,(* size wordsize))
                    `(current-frame-offset)
                    (rp-label value)
+                   ;;; FIXME: hardcoded number of bytes
                    '(byte 0)
                    '(byte 0)
                    '(byte 0)
@@ -2467,6 +2468,7 @@
                    `(int ,(* size wordsize))
                    `(current-frame-offset)
                    (rp-label value)
+                   ;;; FIXME: hardcoded number of bytes
                    LCALL
                    `(call (label ,target))
                    `(addl ,(* (fxsub1 size) wordsize) ,fpr)
@@ -2478,6 +2480,7 @@
                    `(int ,(* size wordsize))
                    `(current-frame-offset)
                    (rp-label value)
+                   ;;; FIXME: hardcoded number of bytes
                    '(byte 0)
                    '(byte 0)
                    LCALL
@@ -2577,11 +2580,6 @@
              (set-cdr! tc (append hand (cdr tc)))))
          (parameterize ([exception-label L])
            (E body (cons L2 ac))))]
-      ;[(shortcut body handler) 
-      ; (let ([L (unique-label)] [L2 (unique-label)])
-      ;   (let ([ac (cons L (E handler (cons L2 ac)))])
-      ;     (parameterize ([exception-label L])
-      ;        (E body (cons `(jmp ,L2) ac)))))]
       [else (error who "invalid effect" (unparse x))]))
   ;;;
   (define (unique-interrupt-label)
@@ -2756,6 +2754,7 @@
            '(int 0)        ; if the framesize=0, then the framesize is dynamic
            '(current-frame-offset)
            '(int 0)        ; multiarg rp
+           ;;; FIXME: hardcoded number of bytes
            (byte 0)
            (byte 0)
            L_CALL
diff --git a/scheme/ikarus.compiler.ss b/scheme/ikarus.compiler.ss
index de58a01..ea65faa 100644
--- a/scheme/ikarus.compiler.ss
+++ b/scheme/ikarus.compiler.ss
@@ -1987,9 +1987,14 @@
   (define record-pmask 7)
   (define disp-struct-rtd     0)
   (define disp-struct-data    wordsize)
-  (define disp-frame-size    -17) ;; OUCH
-  (define disp-frame-offset  -13) ;; OUCH
-  (define disp-multivalue-rp  -9) ;; OUCH
+
+  ;;; refer to the picture in src/ikarus-collect.c for details
+  ;;; on how call-frames are laid out.  (search for livemask)
+  (define call-instruction-size 5)
+  (define disp-frame-size    (- (+ call-instruction-size (* 3 wordsize))))
+  (define disp-frame-offset  (- (+ call-instruction-size (* 2 wordsize))))
+  (define disp-multivalue-rp (- (+ call-instruction-size (* 1 wordsize))))
+
   (define dirty-word -1))
 
 ;(define pcb-allocation-pointer    (*  0 wordsize)) NOT USED
@@ -2324,6 +2329,7 @@
               `(int ,(fx* wordsize 3))
                '(current-frame-offset)
               (label-address L_cwv_multi_rp)
+              ;;; FIXME: hardcoded number of bytes
               (byte 0)
               (byte 0)
               (label L_cwv_call)
diff --git a/scheme/last-revision b/scheme/last-revision
index a3285fb..07f7d5f 100644
--- a/scheme/last-revision
+++ b/scheme/last-revision
@@ -1 +1 @@
-1308
+1309
diff --git a/src/ikarus-enter.s b/src/ikarus-enter.s
index 6509785..3afda16 100644
--- a/src/ikarus-enter.s
+++ b/src/ikarus-enter.s
@@ -22,6 +22,13 @@
 .globl _ik_foreign_call
 .globl ik_asm_reenter
 .globl _ik_asm_reenter
+
+
+#if __x86_64__
+
+####################################################################
+# 64-bit
+
 .align 8
 ik_asm_enter:
 _ik_asm_enter:
@@ -35,7 +42,6 @@ _ik_asm_enter:
   movl 0(%esi), %ebp     # allocation pointer is at 0(pcb)
   movl %esp, %eax
   subl $16, %esp         # 24 for alignment
-# set_stack:
   movl %esp, 24(%esi)    # save esp in pcb->system_stack
   movl 8(%esi), %esp     # load scheme stack from pcb->frame_pinter
   jmp L_call
@@ -47,11 +53,9 @@ _ik_asm_enter:
   .byte 0
   .byte 0
   .byte 0
-#ifdef __x86_64__
-  .long 0 # FIXME
-#else
-  .long  L_multivalue_underflow
-#endif
+L_multivalue_label: # FIXME
+  .long 0           # 2 longs 
+  .long 0           # for return address
   .byte 0
   .byte 0
 L_call:
@@ -72,6 +76,7 @@ L_multivalue_underflow:
   addl $4, %esp
   jmp L_do_underflow
 
+
 .align 8
 ik_asm_reenter:
 _ik_asm_reenter:
@@ -127,29 +132,141 @@ L_two:
 L_one:
   push $0
 L_zero:
-#if __x86_64__
   push %rsi             # (pushl pcr)
-#else 
-  push %esi             # (pushl pcr)
-#endif
   cmpl $0, %eax          # (cmpl (int 0) eax)
   je L_set               # (je (label Lset))
 L_loop:                  # (label Lloop)
   movl (%ebx,%eax), %ecx # (movl (mem ebx eax) ecx)
-#if __x86_64__
   push %rcx             # (pushl ecx)
-#else
-  push %ecx             # (pushl ecx)
-#endif
   addl $4, %eax          # (addl (int 4) eax)
   cmpl $0, %eax          # (cmpl (int 0) eax)
   jne L_loop             # (jne (label Lloop))
 L_set:                   # (label Lset)
-#if __x86_64__
   call *%rdi             # (call cpr)
-#else
-  call *%edi             # (call cpr)
-#endif
   movl 8(%esi), %esp     # (movl (pcb-ref 'frame-pointer) fpr)
   movl 0(%esi), %ebp     # (movl (pcb-ref 'allocation-pointer) apr)
   ret                    # (ret)))
+
+#else  
+
+####################################################################
+# 32-bit
+
+.align 8
+ik_asm_enter:
+_ik_asm_enter:
+  # ignored value is the third arg 12(%esp)
+  # code is the second arg  8(%esp)
+  # pcb is the first arg    4(%esp)
+  # return point is at      0(%esp)
+  movl %esi, -4(%esp)    #  preserve
+  movl %ebp, -8(%esp)    #  preserve
+  movl 4(%esp), %esi   
+  movl 0(%esi), %ebp     # allocation pointer is at 0(pcb)
+  movl %esp, %eax
+  subl $16, %esp         # 24 for alignment
+  movl %esp, 24(%esi)    # save esp in pcb->system_stack
+  movl 8(%esi), %esp     # load scheme stack from pcb->frame_pinter
+  jmp L_call
+  .byte 0
+  .byte 0
+  .byte 0
+  .byte 0
+  .byte 0
+  .byte 0
+  .byte 0
+  .byte 0
+  .long  L_multivalue_underflow
+  .byte 0
+  .byte 0
+L_call:
+  call *8(%eax)         # goooooooo
+  # now we're back
+ik_underflow_handler:
+  movl %eax, -8(%esp)   # store the return value
+  movl $-4, %eax        # set rvcount = 1
+L_do_underflow:
+  movl %esp, 8(%esi)    # store scheme stack in pcb->frame_pointer
+  movl %ebp, 0(%esi)    # store allocation pointer
+  movl 24(%esi), %esp   # restore system stack
+  addl $16, %esp        # 24 for alignment (>= 16)
+  movl -4(%esp), %esi   # restore callee-save registers
+  movl -8(%esp), %ebp   #
+  ret                   # back to C, which handled the underflow
+L_multivalue_underflow:
+  addl $4, %esp
+  jmp L_do_underflow
+
+
+.align 8
+ik_asm_reenter:
+_ik_asm_reenter:
+  # argc is at 12(%esp)
+  # scheme stack is third arg   8(%esp)
+  # pcb is the first arg        4(%esp)
+  # return point is at          0(%esp)
+  movl 12(%esp), %eax
+  movl  8(%esp), %ebx
+  movl %esi, -4(%esp)
+  movl %ebp, -8(%esp)
+  movl 4(%esp), %esi   
+  movl 0(%esi), %ebp     # allocation pointer is at 0(pcb)
+  subl $16, %esp         # 24 for alignment
+  movl %esp, 24(%esi)    # save esp in pcb->system_stack
+  movl %ebx, %esp        # load scheme stack from second arg
+  cmpl $-4, %eax
+  jne L_multi_reentry
+  movl -4(%esp), %eax
+  ret
+L_multi_reentry:
+  movl 0(%esp), %ebx
+  jmp *-9(%ebx)
+
+
+.align 8
+ik_foreign_call:
+_ik_foreign_call:
+  movl %esp, 8(%esi)     # (movl fpr (pcb-ref 'frame-pointer))
+  movl %ebp, 0(%esi)     # (movl apr (pcb-ref 'allocation-pointer))
+  movl %esp, %ebx        # (movl fpr ebx)
+  movl 24(%esi), %esp    # (movl (pcb-ref 'system-stack) esp)
+  # %esp is the system stack, %eax is the index to the last arg,
+  # %esi is the pcb.
+  # Now, the value of %esp is 16-byte aligned
+  # we always push %esi (4 bytes) and do a call (4 bytes),
+  # 0 args require 6 (2) pushes => argc=   0 (0000): %esp +=  -8
+  # 1 args require 5 (1) pushes => argc=  -4 (1100): %esp +=  -4
+  # 2 args require 4 (0) pushes => argc=  -8 (1000): %esp +=   0
+  # 3 args require 3 (3) pushes => argc= -12 (0100): %esp += -12
+  movl %eax, %ecx
+  andl $15, %ecx
+check_ecx:
+  cmpl $8, %ecx
+  je L_zero
+  cmpl $12, %ecx
+  je L_one
+  cmpl $0, %ecx
+  je L_two
+  push $0
+L_two:
+  push $0
+L_one:
+  push $0
+L_zero:
+  push %esi             # (pushl pcr)
+  cmpl $0, %eax          # (cmpl (int 0) eax)
+  je L_set               # (je (label Lset))
+L_loop:                  # (label Lloop)
+  movl (%ebx,%eax), %ecx # (movl (mem ebx eax) ecx)
+  push %ecx             # (pushl ecx)
+  addl $4, %eax          # (addl (int 4) eax)
+  cmpl $0, %eax          # (cmpl (int 0) eax)
+  jne L_loop             # (jne (label Lloop))
+L_set:                   # (label Lset)
+  call *%edi             # (call cpr)
+  movl 8(%esi), %esp     # (movl (pcb-ref 'frame-pointer) fpr)
+  movl 0(%esi), %ebp     # (movl (pcb-ref 'allocation-pointer) apr)
+  ret                    # (ret)))
+
+#endif 
+