3 Nov
2025
3 Nov
'25
11:04 a.m.
On Nov 2, 2025, at 8:25 PM, David Gesswein
<djg(a)pdp8online.com> wrote:
On Sun, Nov 02, 2025 at 02:06:00PM -0500, Paul Koning wrote:
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.
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_i…
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
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
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.