3b1 tape drive blues

[John Campbell]

>From article <1991Feb22.062723.333 at texrex.uucp>, by rmfowler at texrex.uucp (Rex Fowler):
> 
> I just purchased a tape drive and controller for my 3b1.  When
> I run the tape diagnostics, the 3 tests for the controller pass but
> then it says the tape drive isn't ready.  The tape drive is plugged
> in, connected to the board, and a tape is inserted and the retension
> phase seems to work ok.  Latch is closed also(pointing up).
> 
> The green light never comes on.  
> 

Let me add my experience and ask for the tape experts to jump in  here on
the net.   

I have one tape controller/tape drive and a 7300 converted to a 3b1 (machine
A) as well as a real 3b1 (machine B).  A friend has a 3b1 also, with the
hardware patches to run a second disk (machine C).  Now on machines A and
C the floppy tape works just fine.  It runs through the diagnostics on both
and does all tape functions just fine (tapecpio, formatting from diagnostics,
etc.)

On machine B the tape drive behaves as described by Rex above.  In other words,
the same controller, tape drive and cable that works fine in two machines
fails in my third machine!  I've even changed out the CPU and ROMS between
machine A and machine B with no luck.   Machine B, by the way, passes all
standard diagnostics but fails the floppy tape diagnostics.

Again, the machine that fails will pass the controller diagnostics and then
tell me that tape drive is not ready.  I'm sure both Rex and I are wondering
what signal is used to tell the 3b1 that the tape drive is ready and what
possible explanation there would be that could explain the above situation.

Rex, it may be that there is nothing wrong with your cable, tape drive
or controller board.  Know anyone nearby who would let you use your floppy
tape on their machine?
-- 
	John Campbell               jdc at naucse.cse.nau.edu
                                    CAMPBELL at NAUVAX.bitnet
	unix?  Sure send me a dozen, all different colors.