HP 7970E - interest to split?

Chuck Guzis cclist at sydex.com
Sat Sep 30 00:32:29 CDT 2017

On 09/29/2017 03:01 PM, Al Kossow via cctalk wrote:
> On 9/29/17 11:35 AM, Chuck Guzis via cctalk wrote:
>> Does the little Kennedy drive have a vacuum takeup reel?
> No, they are tension arm, very similar design to the 7970
> I wanted to compare the mechanical design of the 9000 to the 7970
> but don't know if I have the time/interest any more.

No, that's not what I meant.  Some drives put a slight vacuum on the
takeup reel hub, so that the tape "sticks" to the hub--no finger hole

I've got all the programming done for the drive, including auto retries
if there's a parity error.   Reading is pretty good for 50+ year old
tapes (the ones I'm reading appear to be from the 1976 Viking missions).
 They look like session transcripts--you can see the command and the

Still a few too many read errors for my taste, so this weekend is going
to be a session with a 'scope and alignment tape.   I think I've got a
way to adjust skew--just hook a logic analyzer probe to each channel and
set the LA to trigger on state changes.   The HP box I'm using is good
to about 25 nsec.


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