(Classic Computers) HP 7970 1/2" 9-Track Reel-to-Reel Tape Drive

Jack Harper harper at secureoutcomes.net
Tue Oct 3 18:50:35 CDT 2017

Hello List -

I just joined the list a few days ago. I am delighted to have found you.

I have a couple of questions about the gorgeous HP 7970 Tape Drive - 
e.g., http://hpmuseum.net/images/7970A-43.jpg

Question:  I understand that most (all?) of the '7970 drives 
interfaced through the HP-IB IEEE-488 bus.  Do most (all?) of the 
tape drives include an HP-IB interface card?? Reason that I ask is 
that reading the 7970 specifications documentation makes me wonder as 
it really talks only about signal lines that do specific tapey things 
such as REWIND and the like and not anything that I saw specifically 
about HP-IB?   So, if I find a 7970 somewhere can I reasonably assume 
that the HP-IB interface card will be there?

Question:  I contemplate talking to the 7970 from the Motorola 68060 
development system that I have assembled through a VME <-> HP-IB 
interface VME board. There appears to be good documentation for such 
a VME <-> HP-IB board and I wonder if it makes sense to try to build 
a simple device driver for the 7970 tape drive in 68K assembly???   I 
do have a listing, for example, of an 7970 device driver written in 
HP2100 assembly language and could use that as a rough template, 
especially if I kept things as simple possible with polling, minimal 
if no interrupts, no DMA etc.  I wrote a lot of HP2100 assembly 
language software back ion the day and can understand that without 
too much difficulty - and I also built device drivers in 68K assembly 
years and years ago in another life.  Does any of that make 
sense??????  Has anyone tried that sort of thing?

Question:  Has anyone tried to control a 7970 tape drive by using 
pure digital output - there are VME boards that make that easy to do 
that have, say, 32 input/output digital lines that are easy to 
read/write from within the 68K world.   Is that a feasible thing to 
think about or just madness?  At first blush, I can see how a 50Mhz 
68060 processor should be able to keep up with an early 1970's tape 
drive - or, maybe not...

Question:  Anyone have experience talking to a 7970 tape drive from 
something other than an HP computer - something that does not have 
HP-IB???  How is that usually done??

I greatly appreciate any advice and/or counsel.

Regards to the List,

Jack Harper
Evergreen, Colorado

Jack Harper, President
Secure Outcomes Inc
2942 Evergreen Parkway, Suite 300
Evergreen, Colorado 80439 USA

303.670.3750 (fax)

http://www.secureoutcomes.net for Product Info. 

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