It was an old mate of mine who introduced me to the phrase ‘play value’. It’s used to describe a machine with lots of dials, buttons and switches with which you can amuse yourself.
I think we were both staring into the cockpit of an AV-8B Harrier II jet fighter, parked at a US Marine Corps base in North Carolina, when he first said it.
“Hell,” he muttered, “this thing really has play value.”
And play value is a feature of many vintage and retro computers. These are not mere beige boxes where the only controls are the boring old keyboard and a mouse. Think of the venerable Altair 8800 where you had to enter code in binary via a delicious row of front panel switches.
I’m a big fan of control surfaces and blinkenlights. A computer is not a real computer unless it’s flashing inscrutable codes via rows of LEDs. That’s why I added an LED matrix to the HMV1960 project even though it does nothing useful.
The Dreambox will perforce be slightly different. It’s meant to sit at the bedside and lull me to sleep. Frantic blinkenlights are not conducive to slumber. In fact, when it use the machine will have to be completely dark because the More Significant Other is very sensitive to light at night. So the Dreambox will need a ‘dark mode’.
Also, my need for controls is minimal. The audio output will be, for the most part, at a preset volume (and be delivered via headphones). I’m building a web interface for the system settings, so I don’t actually require a volume control.
But to hell with that. I’m going to have one anyway. And other controls that will… that will… oh screw it, we’ll decide that later.
The radio-cassette machine that I gutted to act as an enclosure for this project had three dials at the front. The left-most one I’ve already replaced with a USB & 3.5mm audio jack extension cable. This is meant for cars and boats, so that you can dash-mount sockets for your favourite portable audio device. That leaves two holes in the front of the box.
The IQaudIO DAC that is now sitting on top of the Raspberry Pi destined for this project has a three-wire connector to accommodate an encoder to control output volume. And so I’ve mounted two encoders on a piece of stripboard which I’ll mount with screws inside the case. Luckily, the spacing of the stripboard holes align exactly with the spacing of the holes in the case. On the reverse side I’ve soldered male headers to make it easy to attach & detach cables during the development process. The larger holes in the stripboard are for mounting screws.
That leaves one encoder for some as-yet undecided purpose. Oh, and both encoders also have push switches. I intend to use one to turn off the TFT LCD display and put the machine into dark mode. As for the other switch … well, we’ll see. Whatever function it eventually serves, it can only add to the Dreambox’s play value.