[TUHS] Several QD-600A Tapes from Bell Labs Circa Early 90s

[segaloco via TUHS]

On Wednesday, May 28th, 2025 at 2:20 PM, r.stricklin <bear at typewritten.org> wrote:

> Forgot to mention, with relevance to the OP - Sony carts are the one brand that I find have most consistently avoided nearly all the worst problems. This is not a promise, but the odds of you having gotten lucky are far better with Sony than any other. You’ll still have to solve the problem of replacing deteriorated tension belts. Despite the assorted advice circulating on the internet, this problem has not been solved. But for doing a single read, any of that advice will reasonably serve the purpose.
> 
> If the carts have been affected, running them in a drive, even a little bit, once, is a terrific way to make sure they are a headache forever after.
> 
> ok
> bear.
> 
> > On May 28, 2025, at 2:12 PM, r.stricklin bear at typewritten.org wrote:
> > 
> > > On May 28, 2025, at 1:15 PM, Al Kossow aek at bitsavers.org wrote:
> > > 
> > > On 5/28/25 12:58 PM, segaloco via TUHS wrote:
> > > 
> > > > Hello everyone, I'm just putting feelers out for a potential data recovery
> > > > project that may have some UNIX history nuggets hiding somewhere. I just closed
> > > > on this
> > > 
> > > Talk to Bear Striklin (typewritten.org) who has extensive RECENT experience recovering QIC tapes
> > 
> > It’s true.
> > 
> > Nothing I’ve tried has been truly reliable in terms of dealing with the inevitable mechanical problems arising from age related decay of these carts. They are an absolute disaster, easily an order of magnitude or two worse than TK50 ever was. Honestly I’d sooner face the task of recovering a stack of 100 TK50 carts than face another 5 DC600 QICs.
> > 
> > That said:
> > 
> > I have recently worked out a process that looks promising. But I’ve also had this experience with DC600 more than a handful of times, and each time, in the fullness of time, it turned out I had just gotten lucky in some specific regard.
> > 
> > It’s worth noting that sometimes, carts have survived into their senescence without succumbing to the worst of the mechanical troubles. Those tapes are easy, one pass, get it done, move on with life. When that hasn’t happened, the process is utter hell. I can tell in about twenty seconds by visual inspection which category a tape is likely to fall into. Some brands are better than others, but this is still no guarantee.
> > 
> > If it turns out this new process is actually reliable (and is not just revealed to be another form of roll-the-dice) I will share it. It’s better for everyone if I’m not the only person doing this work. It’s nowhere near a science, but art can still be practiced and passed on.
> > 
> > I am currently sitting on a backlog of more than a thousand carts, both mine and others’, with no viable path to clearing it within the next year. So I am not taking on any more of this sort of work, for the moment. It’s not impossible I could start taking work again, but I can’t promise when that might be.
> > 
> > ok
> > bear.

Thank you Bear, this is very good background on the current state of archiving
these tapes.  Seeing as you have a backlog currently I will plan on keeping the
tapes safe and sound once I get ahold of them until such time as you or someone
else can offer some assistance.  I'll keep them stashed with a 5ESS hard disk
that I'm also hoping to eventually get an image off of.

Additionally when/if you do lock in that process you're alluding to I am
certainly interested in studying it out and seeing if I can replicate whatever
it is.  Of course I'd experiment on low-risk tapes I can get my hands on first
before turning any uncertain tooling on these Bell Laboratories tapes.

- Matt G.