Read beyond EOT rst8?

[Yukon Kid]

OK, suppose I inadvertently, somehow, put an EOT at the beginning
of a valuable QIC-24 tape.  (IDIOT!  I know, I know %^)  I REALLY 
need some of the information previously recorded by 

  tar cvpf /dev/rst8

on this tape.  Is there any way I can get at the data beyond what 
looks to be an EOT at the very beginning of the tape?  The tape 
behaves as if I've overwritten an rst8 tar tape, but with a 
zero length file, or something.  My only feedback, whether
tar [rst8/0], dd, or mt, is:  

  tar: tape read error: I/O error
 
or variations, with `I/O error' consistent.  mt's fsf 1
is not useful.  dd with conv/noerror tries forever to get 
past whatever's been put on the tape, but doesn't get anywhere.
(If I use /dev/nrst8 with this, and afterwards do a rewind, there 
is no rewind.  It hasn't got anywhere.  I/O error keeps happening
ad infinitum.)  retension doesn't help.

I wouldn't betray my foolishness unless it were important to
me.  I do know there is good data beyond the start of the tape.
(My guess about how an EOT, if that's what it is, got at the front 
of the tape is that my drive, after a cleaning, wouldn't write at all 
for a short time, and I had tried to write on this IMPORtant [financial
backup!] tape.)  My tape drive itself seems to be fine now - reading, 
writing my own & other machines tapes.

I am quite willing to physically cut the tape, or mis-align the head, 
or whatever.  I guess the rst8 format writes all over the tape, and 
it maybe is impossible to synch up with beginning of block (?), but 
I have to ask.  Anybody got an idea?

Thanks for anything,

-john

Ps: Oh, if I can get raw data in my machine via dd, or something, 
I would be HAPPY to cut it up further using dd & od, etc.
 
Pps: Having duplicated the problem on a throwaway tape (I THINK),
I try to write an `eof', thinking to overwite an `eot', I get
hardware error - st0:  illegal command.

John Eadie  Computing Art Inc  (416) 536-9951  
e-mail: jeadie at sun.COM | jae at c-art.UUCP | {uunet,suncan}!c-art!jae 

`these deepest problems are in fact *not* problems at all.' - Wittgenstein