I am attaching two pictures of my SleepEasy dated Feb 8, 1985. It looks like the picture Zonk uploaded except mine has a large air intake with a cloth filter on the side. It first came with the circuit shown on Zonks post but was updated to I think the Sanders Circuit. If this upload works ok I can send pictures of the inside plus details on the circuits, masks etc.
The base machine is 16 1/2" H, 9 1/2"W, & 7 1/4" D, Weight 15 1/2 Lb.
I used a stand alone unheated humidifier with the unit. It had a single speed 110 Volt AC(Alternating Current) motor and the only control was the switch. It was either on or off. The user pressure was controlled by purchasing a mask calibrated to your prescription. I had several masks I guess so that I could experiment and see which worked best.
It wasn't quiet but the sound was pretty uniform so my wife said she didn't have a problem with it. It was like background noise to her.
It still works. A few years ago we were going somewhere where we needed to blow up air mattresses so I took along the SleepEasy and it did the job with power to spare.
Ok. The picture upload is not working for me yet so pictures will come later.