How to get past end of cpio archive on tape

[Edward N. Kittlitz]

Cartridge tapes are recorded in "serpentine" format. I believe a 150MB
tape has 18 tracks. You can think of it as
	1->1->1->.....1->
	2<-2<-2<-....<-<2
	3->3->3->.....3-> etc.
(although it isn't actually in that order).  I am no peripherals expert,
but it seems to me that there are several advantages:
- as recording heads (tracks) get thinner, you get more on the
  same length of tape. Of course you probably need to make
  the tape with a better magnetic coating, but you aren't doing
  the audio cassette trick of thinner tape (am I correct here?) to
  get more info into the same physical cartridge container.
- it should be easier to keep the tape streaming, because a track is
  only 1 bit wide.

>From my reading of the Wangtek 5150 and Archive 2150 manuals, the erase
head is full width. I don't know if there are actually 18 
"tips" on a fixed head for recording/sensing, or whether the record/sense
head moves up and down. I have a suspicion it is the latter, as I have
watched an internal cart-tape drive move a head assembly across the
width of the tape during tape load.
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E. N. Kittlitz		kittlitz at granite.cr.bull.com
Contracting at Bull, but not alleging any representation of their philosophy.