I've checked in a revision of SRFI 68:

http://srfi.schemers.org/srfi-68/

This is meant to incorporate most of the suggestions people have made:

- I've made the procedures in the Imperative I/O layer consistent with
  those in the Stream I/O layer, as per Taylor Campbell's suggestion:

  o The ports argument is now mandatory and always come first.
  o The ports procedures now correspond directly with the stream
    procedures.
  o The CURRENT-xxx-PORT procedures are gone; STANDARD-xxx-PORT
    procedures were added.
  o The OPEN-xxx procedures were renamed consistently with the streams
    layer.
  o END-OF-STREAM? was renamed to STREAM-EOF?, EOF? was renamed to
    PORT-EOF?

- The translator for an output stream now gets called on every flush,
  as per Shiro Kawai's suggestion.

- The update form for transcoder was splitt off from the TRANSCODER
  form the the UPDTAE-TRANSCODER form.

- The SRFI clarifies that file option objects and transcoder objects
  may carry platform-specific extensions.

- Other minor changes.

Many thanks everybody for posting suggestions; they were extremely
helpful.

I haven't switched the SRFI from octet vectors to blobs yet.  I intend
to do that with the next revision.  If you think I shouldn't, please
let me know.

(Of course, if you think other changes should be made, let me know,
too.)

--
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla