Toilett processing (Was: ZX-TEAM meeting and Webcam)

From: Fred Cisin <>
Date: Wed Mar 20 11:54:25 2002

> > > > That is easy -- a micro switch ... now how do you tell if the ROLL is
> > > > almost empty ?
> >
> > > Press-fit roll spindle with shaft encoder attached to... a PDP-11...
> Or an optical sensor mounted parallel the axis of the roll that would
> trigger when the diameter was too low. How about a color-based sensor
> that could detect the difference between the cardboard core and the
> paper? What about a shaft encoder that measures angular velocity...

Or thermal sensors and heaters - apply a quick burst of heat outside the
roll, and see how quickly the spindle sensor responds to measure amount of
Or only use rolls with factory installed sensors
Or measure diameter of roll with optical sensors or microswitch from the
Or build a dispenser, and have it maintain an inventory count
Or build a dispenser with a long paper path, and just have a microswitch
paper-out sensor a few feet from the output of the dispenser.

> > Isn't using a PDP-11 as perhipheral processor for a ZX81
> > a bit out of scope ?

Why? Isn't a PDP-11 adequate?

30 years ago, at GSFC, we used a 360 for I/O for a 7094.

> The point is, who says the peripherals have to be less powerful than the
> core?
When the original LaserWriter came out, it was substantially more powerful
than the current Macs.

Grumpy Ol' Fred
Received on Wed Mar 20 2002 - 11:54:25 GMT

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