> On Nov 2, 2025, at 8:25 PM, David Gesswein <[email protected]> wrote:
>
> On Sun, Nov 02, 2025 at 02:06:00PM -0500, Paul Koning wrote:
>>
>> Is Dave's setup a DECtape drive, with 10 tracks on 3/4 inch width?
>>
> Drive is actually LINCtape with weird tape path so DECtapes need to be
> respooled on another drive to LINCtape orientation.
> Looks like this
> https://www.ricomputermuseum.org/collections-gallery/interesting_computer_items/computer-operations-inc-linc-tape
Which one? There are two pictures which look like mirror images. The one on
the left (part of the ad) would be compatible with the way DECtape reels are
normally spooled.
> All tracks are available from the head separately except mark track which
> is why I picked it.
I'm puzzled how you would read a tape without having the mark track. Or do you
mean that the two copies of the data tracks are available as separate signals
but the mark track is a single signal (presumably summing the two mark tracks)?
What about the timing track?
> Current project is LINCtapes. Need to do some code changes to merge in my
> DECtape decoder. Bottom links are recent stuff.
> https://www.pdp8online.com/images/index.shtml
>
>> Analog capture would be a great option for old tapes. It's likely there
>> will be tapes that don't read cleanly with standard controllers, but could
>> be recovered with analog capture and good DSP.
>>
> So far not much DSP. Deskew and handling mark track errors seems to get most
> blocks.
Interesting. Well, we know DECtape was pretty robust, though it *is* possible
to wear it out, I saw id done repeatedly at my college where DECtape was (in
1973) used as the public file system for RSTS-11. On the other hand, a former
DEC guy told about a DECtape reel that accidentally was run through the laundry
(it was in a pocket) and worked just fine afterwards. :-)
paul
