Real tape drive densities [was RE: Oregon Pascal tape found]

[Curious Marc]

Nice unit! Drool. Looks like this is a NRZI triple density tape, so  7970A or B. The later 7970E would have a 1600 PE density switch too. I have an E, but not with the multiple density or 7 track options unfortunately. Thanks for the link to the series overview manual Rich.
Marc

Sent from my iPad

> On Feb 10, 2016, at 11:40 AM, Rich Alderson <RichA at LivingComputerMuseum.org> wrote:
> 
> From: Christian Corti
> Sent: Wednesday, February 10, 2016 2:28 AM
> 
>> On Tue, 9 Feb 2016, Pete Lancashire wrote:
> 
>>> There are a few odd balls in 9-track as well, but the 556 was a typo.
> 
>> Really?
> 
>> I actually *do* have a 9 track tape drive (HP 7970) that has 200/556/800 
>> bpi densities:
> 
>> http://computermuseum.informatik.uni-stuttgart.de/pics/hp1000/hp7970_2.jpg
> 
>> And it is a *9* track tape, I know for sure.
> 
> Actually, what you have is a *dual-density* tape drive, an HP7970E.  It
> will write 9-track tapes at 800bpi, or 7-track tapes at 200, 556, or 800.
> 
> See the manual for the 7970 drive family at
> 
> http://bitsavers.informatik.uni-stuttgart.de/pdf/hp/tape/7970/07970-90885_7970oper_Dec76.pdf
> 
>                                                                Rich
> 
> 
> Rich Alderson
> Vintage Computing Sr. Systems Engineer
> Living Computer Museum
> 2245 1st Avenue S
> Seattle, WA 98134
> 
> mailto:RichA at LivingComputerMuseum.org
> 
> http://www.LivingComputerMuseum.org/