Monthly Archives: April 2016

PiDP-8/I Simulator

I have a brief but ancient history with the PDP-8 from Digital Equipment Corporation. I started working for DEC in the winter of 1977/78, just after my senior year in high school. I was in college studying radio/television production. When a film crew arrived one day to make a training video for the company, I asked if I could intern on the project. I’d worked there a while by then and had a good relationship with my boss, so I got a green light to do it.

The training video project was for a dedicated bed-of-nails tester for the new PDP-11/23 board that was about to go from prototype assembly to full production in Puerto Rico. The facility that I worked at performed central incoming chip testing as well as the prototype assembly process for the PDP-11/23. All of the test equipment was driven by DEC PDP computers, which was pretty impressive.

The test machine we were making a video for had a massive amount of input/output pins that were controlled by the PDP-8. It had a paper tape reader, an RK08, a console terminal interface and an expansion chassis that led to the 3rd-party I/O pin controllers and timing hardware. The bed of nails fixture was built specifically for the PDP-11/23 and used sharp spring loaded pogo pins for connectivity to all the “special places” to be probed on the underside of the board.

In the training video, I showed how to perform the boot process, that involved loading a series of commands into the front panel in octal. These steps told the machine how to read the paper tape. The next step was to run what the paper tape loaded (The tape drive), which was the program that knew how to spin up and use the RK08 disk and make the serial terminal work. From there, the text application could be executed from the operator terminal.

So where is all this leading?

I just purchased a kit from Oskar Vermeulen called PiDP-8, a PDP-8/I simulation with real front panel switches and blinken lights. Yes, Blinken does mean “to flash” in German. The kit is based on a Raspberry Pi and uses the SIMH computer simulation program.


His website is at Obsolescence Guaranteed

I’m still waiting for the kit to arrive… but I have the PI running.

Screenshot 2016-04-26 20.11.40

Arduino IDE on Ubuntu – easy way

Here is the simplest way to get the latest Arduino IDE installed on a freshly installed  Linux Ubuntu distribution.  The version of Arduino that is in the default repository is now a few years old, and in fact, the version you will get is officially “…no longer supported by the development team.”

But, there is an upside to this.  By performing the following command you get a complete guided installation that will install all the compiler dependencies and do nice things such as making your account part of the dialout group, which is needed to access the serial port.

sudo apt-get install arduino

So, with this accomplished lets download the latest version from
Arduino Download Page and make sure you choose the linux version that matches your system (32 bit or 64 bit).


NOTE: The latest version is subject to change, so replace references to “1.6.8” with what ever the current downloadable version is.

The installation kit will normally end up in your “Downloads folder” so lets open a terminal window and go there to unpack it.

$ cd Downloads/
$ ls
$ tar -xvf arduino-1.6.8-linux64.tar.xz

This will place the files in a new folder named: arduino-1.6.8

Now, we can place it anywhere, but a nice place to put it is in the /opt top level folder. This can be accomplished with the following step:

sudo mv arduino-1.6.8 /opt

Now, move your /opt folder by typing:

cd /opt/arduino-1.6.8

and then issuing the following command to make this installation of arduino “go live”

chmod +x

You should now have an Arduino icon on your desktop that will open the latest “supported” version of the IDE.