

What kind of cart is it

    Date: Mon, 11 Sep 89 21:22 EDT
    From: pan@Athena.Pangaro.Dialnet.Symbolics.Com (Paul Pangaro)

    Is there a way to tell definitively whether a machine has a new or
    old type cart drive (i.e., what is its maximum storage capacity).
I don't think there's any way the computer can tell; you can tell by
visual inspection.  If memory serves, the old Cipher drives had a built-in
power supply (look for a circuit breaker switch by opening the back door
and looking toward the cart drive) and newer drives installed in 3600
cabinets had a separate power supply down below with small cable running
to power the drive.

However the most reliable way is likely be to try it.
You could mount a scratch tape and execute something like this (I
haven't actually tried it)

(defun test-capacity-by-writing ()
  (condition-case (error)
       (with-open-stream (tape (tape:make-stream :direction :out))
	 (loop with bytes-written
	       do (multiple-value-bind (buffer start limit)
		      (send stream :get-output-buffer)
		    (send stream :advance-output-buffer)
		    (incf bytes-written (- limit start)))))
     (tape:end-of-tape bytes-written)   ;;here when out of room
     (otherwise (si:dbg) bytes-written)));;here on some other error.

    I have 2 3600s, and one clicks and clatters when I put in the
    tape; the other doesn't do that until I perform an operation with
    it. What does this mean? 
That they are two different types of drives.
			     Does it relate to the first question?
Probably;  I'd guess that the one that clicks and clatters when you
first put in the tape is a newer (i.e. higher-capacity) drive.