Re: formating a disk

[barmar@Think.COM (Barry Margolin)]

    Date: Thu, 27 Jun 1991 14:46 EDT
    From: bouma@cs.purdue.edu

    So far I have had nothing but bad!  Why is this procedure so complicated,
    anyway?  

Come on, you've been a Lispm administrator long enough to know that they
are wonderful when they work, but can be real bitches when they're
broken.

	     All I want is a clean disk with the initial FEP filesystem on it.
    Please, someone tell me what it takes to get this done?  Every time it
    seems like I am making some progress I get stuck.  Enough whining, on to
    the facts:

    Once I get the flods loaded, then what?  The documentation says I have to
    "clear machine", "load microcode", "set disk type",  then "disk restore".
    Well, all these operations try to access the tape drive.  What tape am I
    supposed to have in there?  "Clear machine" seems to fail on every tape.
    So I tried just loading microcode from a tape wrote using Paul Cross'
    instructions.  That seemed to take.  Then I dumped the IFS tape in the
    machine and did "disk restore".  That gave an error of "not FEP overlay".
    An annoyance here is that every time you get an error the machine forgets
    all the FEP commands and you gotta reload the flod tape again by typing
    "load cart:" 7 times!

    I appeal to anyone who knows to please explain the procedure.

See if you can get someone at Symbolics to loan you a "Breath of Life"
tape (if they won't lend it, they'll certainly sell you one, for a
couple hundred $).  It's a single tape that has everything that is
needed to resurrect a machine with no working disk.  It includes a
special flod that runs a script to automate the whole process.

Here's why "disk restore" complained about the tape not being a FEP
overlay (i.e. a flod).  The FEP only has enough memory for the contents
of one flod file at a time.  The "scan" command just reads the table of
contents of the file, adding the commands to its index.  When you invoke
a command, it then reads the appropriate flod into memory if necessary
(if you've ever wondered why there's often a pause when you type the
last word of a FEP command, that's what is happening then).  For those
of you who have been computing long enough to remember overlays in
pre-VM OSes, this should seem familiar (and it's why flods are called
"FEP overlays").

So, when you type the FEP command, the FEP has to read the disk flod
file into memory from the tape in order to execute the command.

So, I think it should work to keep the flod tape in the drive except
while you load the microcode from its tape.  Then when you do the disk
restore, wait for the prompt before putting the IFS tape in.

                                                barmar