Real tape drive densities

[Christian Corti]

On Thu, 11 Feb 2016, Christian Corti wrote:
> I have a 7970B (-236) with options 127, 006, 007, 012 and 023.

According to the HP 1000 Peripherals Selection Guide from 1982, page 16, 
option 236 specifies an 800bpi master magnetic tape subsystem with one 
drive and two-card 13181B interface.

And you can't mix 800 and 1600 bpi on the same interface for the HP 1000. 
You need either the 13181 for NRZI, or the 13183 for PE.

So, apparently my NRZI 9 track drive has the density option included, and 
I don't know if there were any other 200/556 bpi 9 track drives out 
there. When we got the drive I had hoped it would be a 7 track drive, but 
it isn't.

Christian