#straight-8

New Post has been published on https://www.aneddoticamagazine.com/1965-dec-pdp-8-pre-restoration-evaluation/

1965 DEC PDP-8 pre-restoration evaluation

The PDP-8 is a 12-bit minicomputer that was produced by Digital Equipment Corporation (DEC). It was the first commercially successful minicomputer, with over 50,000 units being sold over the model’s lifetime. The earliest PDP-8 model, informally known as a “Straight-8”, was introduced on 22 March 1965 priced at $18,500.

New Post has been published on https://www.aneddoticamagazine.com/1965-dec-pdp-8-pre-restoration-evaluation/

1965 DEC PDP-8 pre-restoration evaluation

The PDP-8 is a 12-bit minicomputer that was produced by Digital Equipment Corporation (DEC). It was the first commercially successful minicomputer, with over 50,000 units being sold over the model’s lifetime. The earliest PDP-8 model, informally known as a “Straight-8”, was introduced on 22 March 1965 priced at $18,500.

New Post has been published on https://www.aneddoticamagazine.com/1965-dec-pdp-8-pre-restoration-evaluation/

1965 DEC PDP-8 pre-restoration evaluation

The PDP-8 is a 12-bit minicomputer that was produced by Digital Equipment Corporation (DEC). It was the first commercially successful minicomputer, with over 50,000 units being sold over the model’s lifetime. The earliest PDP-8 model, informally known as a “Straight-8”, was introduced on 22 March 1965 priced at $18,500.

(via https://www.youtube.com/watch?v=sidooQfvH4I)

And now for your enjoyment, the PDP-8 “Straight-8″ power-on ceremony at Vintage Computer Festival East X from last month.

PDP-8 Expert David Gesswein had on display an original PDP-8 also known as the Straight-8.

In 1967, a computer club was formed at Hopewell Valley High School in central New Jersey known as R.E.S.I.S.T.O.R.S. (or Radically Emphatic Students Interested in Science, Technology, and Other Research Studies).  They had access to computers deemed old even at the time, some of which was accessible remotely via the phone line. 

However a few years after their creation, RESISTORS got their hands on the then relatively new PDP-8. It sat in the barn of a man by the name of Claude Kagan, along with a whole treasure trove of old machines (again, even old by late 1960′s standards).  But a PDP-8 in the hands of high school students was unheard of.  You can see the signatures of the RESISTORS on the wooden pallet that the Straight-8 rests on.

A few years ago, this PDP-8 was unearthed from a barn where it had sat for decades in terrible condition.  It was donated to the Mid Atlantic Retro Computing Hobbyists (MARCH).  Late last year, David Gesswein took up the task of restoring it to working condition.  That meant repainting the metal frame, replacing capacitors that had lost their essence long ago, and diagnosing the many faulty logic modules.  Oh, and removing a nest or two that was inside of it.

The internals of this machine are wire-wrapped back planes, along with many many individual logic modules.  Each one is made up of discrete transistors and diodes, known as Diode-Transistor logic -- no integrated circuits on this beast.  The top half folds open to allow access to the back planes for easier servicing.  The base of the unit contains the front panel lights and switches, along with the very heavy power supply and a few fans to cool the logic modules.

However, David was successful in reviving it (albeit with a few logic modules from his own PDP-8′s).  On Friday of VCF East X, we did a special unveiling of the PDP-8 where an original member of the RESISTORS came and told a bit about their organization, and David explained the restoration process he went through briefly.  This was followed up by a ceremonial power-on of the unit which went well (somebody in the background yelled *BOOM* while they were checking the power connectors which I found to be mighty amusing).

During the restoration process, David said that the computer’s magnetic core memory still held the last thing entered into the machine, no doubt from somebody very frustrated with the machine. It said in ASCII: “Computers are shit” much to the amusement of everyone at the ceremony.

On Saturday and Sunday, this Straight-8 was set up near all of the other PDP-8′s and Digital Equipment Corporation machines, hooked into an ASR-33 teletype for everyone to try out.  When I walked by on Saturday, it was running a Lunar Lander simulation game, which I played (and lost), but more on that another time.  I’m still in awe that I was fortunate enough to interact with an original PDP-8