Anyone out there that can read 7 track / 556 BPI tapes? - test-drb@ccmp.vtda.org

18 Jul 2020

Hi,

I bumped into an old friend of mine today.  We both talked about a pair of
machines we worked on that no longer exist as far as we cant tell.  They
were both Adage machines and had the same base digital architecture.  Their
names are Ambilog 200 and AGT-30.  The Ambilog was the predecessor to the
AGT line.  The AGT came in 3 flavors, AGT-10, AGT-30 and AGT-50.  The 30
seems to have been the most prevalent.

They were 30 bit, one's complement machines.  The Ambilog had a beautiful
console that used an IO Selectric.  It was designed as a 2D vector graphics
machine.

Here's an image of the Ambilog 200: Ambilog 200
<https://d.lib.ncsu.edu/collections/catalog/ua023_024-001-bx0010-020-004#?c=&m=&s=&cv=&xywh=-1317%2C-1%2C8308%2C4470>

The AGT/30 was a very advanced 3D vector machine.  The XYZ signals for the
display came from a 4 x 3 "hybrid" matrix multiplier which allowed for 3D
imaging with Z axis depth cueing.  The matrix multiplier was a 19 in rack
of a dozen discrete 15 bit multiplying D to A converters.  About once a
year it had to be re-calibrated due to long term drift.

Here's a link to an image of an AGT-30: Adage AGT-30
<https://www.google.com/url?sa=i&url=http%3A%2F%2Fwhat-when-how.com%2FTutorial%2Ftopic-203v31%2FThe-History-of-Visual-Magic-in-Computers-358.html&psig=AOvVaw3M65q2I5e_Z2Nd6JSfMpDc&ust=1595212226314000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCODysemi2OoCFQAAAAAdAAAAABA9>

And here is it's 1.5 seconds of fame from the SciFi classic "Dark Star":
AGT-30
das Blinkenlights <https://youtu.be/ocse-0bBfo8?t=3152>

Anyway, it turns out he has quite a few of the source and backup tapes.
Unfortunately they are 7 track 556 BPI.  So the question is: is there
anyone out there that can assist with either reading these tapes or (better
yet) has a 7 track tape head we could buy?

Our goal is to preserve this forgotten machine designed at the start of the
computer graphics era.  Writing a full emulator is our goal.

I live in the Bay Area.  Maybe those of you with connections to CHM could
see if we could read the tapes on the 1401.  Or maybe one of you has a 7
track driver in your junk file.  All we really would need is the head and
we could put it on an existing drive.  As a last option, a commercial tape
recovery vendor although that is probably too pricey.

Thanks,

Marc Howard