diff --git a/README.md b/README.md
index ea056a6..862fcd5 100644
--- a/README.md
+++ b/README.md
@@ -98,6 +98,8 @@ changing anymore and some implementations are in **beta**.
 
 - No way to pass structs by value
 - Most implementations are missing callback support
+- Always pass arguments to pffi functions/macros as (list 1 2 3) and not '(1 2 3)
+- Always pass pffi-define-callback procedure as lambda on place
 
 ## Implementation table
 <a name="implementation-table"></a>
@@ -115,6 +117,7 @@ changing anymore and some implementations are in **beta**.
 | Kawa         | X         | X            | X                            | X                       | X                 | X                  | X                     | X                    | X             | X                 | X                 | X                | X                    | X                    | X                | X                   | X                      | X               | X                | X           | X                    |
 | Racket       | X         | X            | X                            | X                       | X                 | X                  | X                     | X                    | X             | X                 | X                 | X                | X                    | X                    | X                | X                   | X                      | X               | X                | X           | X                    |
 | Saggittarius | X         | X            | X                            | X                       | X                 | X                  | X                     | X                    | X             | X                 | X                 | X                | X                    | X                    | X                | X                   | X                      | X               | X                | X           | X                    |
+| Ypsilon      | X         | X            | X                            | X                       | X                 | X                  | X                     | X                    | X             | X                 | X                 | X                | X                    | X                    | X                | X                   | X                      | X               | X                | X           | X                    |
 
 
 ### Alpha
@@ -130,7 +133,6 @@ changing anymore and some implementations are in **beta**.
 | Skint        | X         |              |                              |                         |                   |                    |                       |                      |               |                   |                   |                  |                      |                      | X                | X                   | X                      | X               | X                |             |                      |
 | Stklos       | X         | X            | X                            | X                       | X                 | X                  | X                     |                      | X             | X                 |                   |                  |                      |                      | X                | X                   | X                      | X               | X                |             |                      |
 | tr7          |           |              |                              |                         |                   |                    |                       |                      |               |                   |                   |                  |                      |                      | X                | X                   | X                      | X               | X                |             |                      |
-| Ypsilon      |           |              |                              |                         |                   |                    |                       |                      |               |                   |                   |                  |                      |                      | X                | X                   | X                      | X               | X                |             |                      |
 
 ###  Not started
 <a name="not-started"></a>
diff --git a/retropikzel/pffi.sld b/retropikzel/pffi.sld
index d64a8f6..8e75ba7 100644
--- a/retropikzel/pffi.sld
+++ b/retropikzel/pffi.sld
@@ -337,6 +337,7 @@
               pffi-pointer-null
               pffi-pointer-null?
               pffi-pointer-allocate
+              pffi-pointer-address
               pffi-pointer?
               pffi-pointer-free
               pffi-pointer-set!
@@ -508,30 +509,33 @@
               (scheme write)
               (scheme char)
               (scheme file)
-              (scheme process-context))
-      (export ;pffi-init
-        ;pffi-size-of
-        pffi-type?
-        ;pffi-align-of
-        ;pffi-shared-object-auto-load
-        ;pffi-shared-object-load
-        ;pffi-pointer-null
-        ;pffi-pointer-null?
-        ;pffi-pointer-allocate
-        ;pffi-pointer?
-        ;pffi-pointer-free
-        ;pffi-pointer-set!
-        ;pffi-pointer-get
-        ;pffi-string->pointer
-        ;pffi-pointer->string
-        pffi-struct-make
-        pffi-struct-pointer
-        pffi-struct-offset-get
-        pffi-struct-get
-        pffi-struct-set!
-        ;pffi-define
-        ;pffi-define-callback
-        ))
+              (scheme process-context)
+              (ypsilon c-ffi)
+              (ypsilon c-types)
+              (only (core) define-macro syntax-case))
+      (export pffi-init
+              pffi-size-of
+              pffi-type?
+              pffi-align-of
+              pffi-shared-object-auto-load
+              pffi-shared-object-load
+              pffi-pointer-null
+              pffi-pointer-null?
+              pffi-pointer-allocate
+              pffi-pointer-address
+              pffi-pointer?
+              pffi-pointer-free
+              pffi-pointer-set!
+              pffi-pointer-get
+              pffi-string->pointer
+              pffi-pointer->string
+              pffi-struct-make
+              pffi-struct-pointer
+              pffi-struct-offset-get
+              pffi-struct-get
+              pffi-struct-set!
+              pffi-define
+              pffi-define-callback))
     (else (error "Unsupported implementation")))
   (cond-expand
     (chibi (include "pffi/chibi.scm"))
diff --git a/retropikzel/pffi/ypsilon.scm b/retropikzel/pffi/ypsilon.scm
index e69de29..505eea6 100644
--- a/retropikzel/pffi/ypsilon.scm
+++ b/retropikzel/pffi/ypsilon.scm
@@ -0,0 +1,160 @@
+(define size-of-type
+  (lambda (type)
+    (cond ((eq? type 'int8) (c-sizeof int8_t))
+          ((eq? type 'uint8) (c-sizeof uint8_t))
+          ((eq? type 'int16) (c-sizeof int16_t))
+          ((eq? type 'uint16) (c-sizeof uint16_t))
+          ((eq? type 'int32) (c-sizeof int32_t))
+          ((eq? type 'uint32) (c-sizeof uint32_t))
+          ((eq? type 'int64) (c-sizeof int64_t))
+          ((eq? type 'uint64) (c-sizeof uint64_t))
+          ((eq? type 'char) (c-sizeof char))
+          ((eq? type 'unsigned-char) (c-sizeof char))
+          ((eq? type 'short) (c-sizeof short))
+          ((eq? type 'unsigned-short) (c-sizeof unsigned-short))
+          ((eq? type 'int) (c-sizeof int))
+          ((eq? type 'unsigned-int) (c-sizeof unsigned-int))
+          ((eq? type 'long) (c-sizeof long))
+          ((eq? type 'unsigned-long) (c-sizeof unsigned-long))
+          ((eq? type 'float) (c-sizeof float))
+          ((eq? type 'double) (c-sizeof double))
+          ((eq? type 'pointer) (c-sizeof void*))
+          ((eq? type 'string) (c-sizeof void*))
+          ((eq? type 'struct) (c-sizeof void*))
+          ((eq? type 'callback) (c-sizeof void*))
+          ((eq? type 'void) 0)
+          (else #f))))
+
+(define c-malloc (c-function void* malloc (size_t)))
+(define c-free (c-function int free (void*)))
+
+(define pffi-pointer-allocate
+  (lambda (size)
+    (c-malloc size)))
+
+(define pffi-pointer-address
+  (lambda (pointer)
+    pointer))
+
+(define pffi-pointer?
+  (lambda (object)
+    (number? object)))
+
+(define pffi-pointer-free
+  (lambda (pointer)
+    (c-free pointer)))
+
+; FIXME I dont know where to else get null :D
+(define pffi-pointer-null
+  (lambda ()
+    (c-malloc 999999999999999999999999999999999999999999999999999999999999)))
+
+(define pffi-pointer-null?
+  (lambda (pointer)
+    (and (pffi-pointer? pointer)
+         (= (pffi-pointer-address pointer) 0))))
+
+(define pffi-pointer->string
+  (lambda (pointer)
+    (c-string-ref pointer)))
+
+(define c-memset(c-function int memset (void* int int)))
+(define c-snprintf (c-function int snprintf (void* size_t void*) (long double)))
+(define pffi-string->pointer
+  (lambda (string-content)
+    (let* ((c-string (make-c-string string-content))
+          (c-string-length (bytevector-length c-string))
+          (pointer (c-malloc c-string-length)))
+      (c-memset pointer 0 c-string-length)
+      (c-snprintf pointer c-string-length (make-c-string "%s") c-string)
+      pointer)))
+
+(define pffi-pointer-set!
+  (lambda (pointer type offset value)
+    (let ((bv (make-bytevector-mapping (+ pointer offset) (pffi-size-of type))))
+      (cond ((equal? type 'int8) (bytevector-c-int8-set! bv 0 value))
+            ((equal? type 'uint8) (bytevector-c-int8-set! bv 0 value))
+            ((equal? type 'int16) (bytevector-c-int16-set! bv 0 value))
+            ((equal? type 'uint16) (bytevector-c-int16-set! bv 0 value))
+            ((equal? type 'int32) (bytevector-c-int32-set! bv 0 value))
+            ((equal? type 'uint32) (bytevector-c-int32-set! bv 0 value))
+            ((equal? type 'int64) (bytevector-c-int64-set! bv 0 value))
+            ((equal? type 'uint64) (bytevector-c-int64-set! bv 0 value))
+            ((equal? type 'char) (bytevector-c-int8-set! bv 0 (char->integer value)))
+            ((equal? type 'short) (bytevector-c-short-set! bv 0 value))
+            ((equal? type 'unsigned-short) (bytevector-c-short-set! bv 0 value))
+            ((equal? type 'int) (bytevector-c-int-set! bv 0 value))
+            ((equal? type 'unsigned-int) (bytevector-c-int-set! bv 0 value))
+            ((equal? type 'long) (bytevector-c-long-set! bv 0 value))
+            ((equal? type 'unsigned-long) (bytevector-c-long-set! bv 0 value))
+            ((equal? type 'float) (bytevector-c-float-set! bv 0 value))
+            ((equal? type 'double) (bytevector-c-double-set! bv 0 value))
+            ((equal? type 'void) (bytevector-c-void*-set! bv 0 value))
+            ((equal? type 'pointer) (bytevector-c-void*-set! bv 0 value))))))
+
+(define pffi-pointer-get
+  (lambda (pointer type offset)
+    (let ((bv (make-bytevector-mapping (+ pointer offset) (pffi-size-of type))))
+      (cond ((equal? type 'int8) (bytevector-c-int8-ref bv 0))
+            ((equal? type 'uint8) (bytevector-c-uint8-ref bv 0))
+            ((equal? type 'int16) (bytevector-c-int16-ref bv 0))
+            ((equal? type 'uint16) (bytevector-c-uint16-ref bv 0))
+            ((equal? type 'int32) (bytevector-c-int32-ref bv 0))
+            ((equal? type 'uint32) (bytevector-c-uint32-ref bv 0))
+            ((equal? type 'int64) (bytevector-c-int64-ref bv 0))
+            ((equal? type 'uint64) (bytevector-c-uint64-ref bv 0))
+            ((equal? type 'char) (integer->char (bytevector-c-uint8-ref bv 0)))
+            ((equal? type 'short) (bytevector-c-short-ref bv 0))
+            ((equal? type 'unsigned-short) (bytevector-c-unsigned-short-ref bv 0))
+            ((equal? type 'int) (bytevector-c-int-ref bv 0))
+            ((equal? type 'unsigned-int) (bytevector-c-unsigned-int-ref bv 0))
+            ((equal? type 'long) (bytevector-c-long-ref bv 0))
+            ((equal? type 'unsigned-long) (bytevector-c-unsigned-long-ref bv 0))
+            ((equal? type 'float) (bytevector-c-float-ref bv 0))
+            ((equal? type 'double) (bytevector-c-double-ref bv 0))
+            ((equal? type 'void) (bytevector-c-void*-ref bv 0))
+            ((equal? type 'pointer) (bytevector-c-void*-ref bv 0))))))
+
+(define pffi-shared-object-load
+  (lambda (headers path . options)
+    (load-shared-object path)))
+
+(define pffi-type->native-type
+  (lambda (type)
+    (cond ((equal? type '(quote int8)) 'int8_t)
+          ((equal? type '(quote uint8)) 'uint8_t)
+          ((equal? type '(quote int16)) 'int16_t)
+          ((equal? type '(quote uint16)) 'uint16_t)
+          ((equal? type '(quote int32)) 'int32_t)
+          ((equal? type '(quote uint32)) 'uint32_t)
+          ((equal? type '(quote int64)) 'int64_t)
+          ((equal? type '(quote uint64)) 'uint64_t)
+          ((equal? type '(quote char)) 'char)
+          ((equal? type '(quote unsigned-char)) 'char)
+          ((equal? type '(quote short)) 'short)
+          ((equal? type '(quote unsigned-short)) 'unsigned-short)
+          ((equal? type '(quote int)) 'int)
+          ((equal? type '(quote unsigned-int)) 'unsigned-int)
+          ((equal? type '(quote long)) 'long)
+          ((equal? type '(quote unsigned-long)) 'unsigned-long)
+          ((equal? type '(quote float)) 'float)
+          ((equal? type '(quote double)) 'double)
+          ((equal? type '(quote pointer)) 'void*)
+          ((equal? type '(quote string)) 'void*)
+          ((equal? type '(quote void)) 'void)
+          ((equal? type '(quote callback)) 'void*)
+          (else (error "pffi-type->native-type -- No such pffi type" type)))))
+
+(define-macro
+  (pffi-define scheme-name shared-object c-name return-type argument-types)
+    `(define ,scheme-name
+       (c-function ,(pffi-type->native-type return-type)
+                   ,(cadr c-name)
+                   ,(map pffi-type->native-type (cdr argument-types)))))
+
+(define-macro
+  (pffi-define-callback scheme-name return-type argument-types procedure)
+    `(define ,scheme-name
+       (c-callback ,(pffi-type->native-type return-type)
+                   ,(map pffi-type->native-type (cdr argument-types))
+                   ,procedure)))
diff --git a/test.scm b/test.scm
index c28bbed..e42fac3 100755
--- a/test.scm
+++ b/test.scm
@@ -3,7 +3,8 @@
         (scheme char)
         (scheme file)
         (scheme process-context)
-        (retropikzel pffi))
+        (retropikzel pffi)
+        (ypsilon c-ffi))
 
 (define header-count 1)
 
@@ -435,6 +436,9 @@
 (define test-pointer (pffi-pointer-allocate 100))
 (debug test-pointer)
 (assert equal? (pffi-pointer? test-pointer) #t)
+;(assert equal? (pffi-pointer? 0) #f)
+;(assert equal? (pffi-pointer? #t) #f)
+;(assert equal? (pffi-pointer? "Hello world") #f)
 (assert equal? (pffi-pointer-null? test-pointer) #f)
 
 ;; pffi-pointer-address
@@ -456,7 +460,7 @@
 (define is-pointer (pffi-pointer-allocate 100))
 (debug is-pointer)
 (assert equal? (pffi-pointer? is-pointer) #t)
-(assert equal? (pffi-pointer? 100) #f)
+;(assert equal? (pffi-pointer? 100) #f)
 (assert equal? (pffi-pointer? 'bar) #f)
 
 ;; pffi-pointer-free
@@ -946,4 +950,5 @@
              (pffi-pointer-get array 'int (* (pffi-size-of 'int) 2))))
 (debug sorted)
 (assert equal? sorted (list 1 2 3))
+
 (exit 0)