binary representation of numbers

[Rohan Drape]

Hello All,

I have searched the documentation but cannot find procedures to convert 
between scheme numbers and common machine byte representations.  I need 
something equivalent to the PLT procedures:

(integer-byte-string->integer string signed? [big-endian?])
(integer->integer-byte-string n size-n signed? [big-endian? to-string])
(floating-point-byte-string->real string [big-endian?])
(floating-point-byte-string->real string [big-endian?])

which assume of course that strings are byte vectors.  These are required to 
implement a simple byte protocol over UDP.  I am sure this is `under my nose' 
but I cannot find it, any pointers would be appreciated.

Regards,
Rohan