--- Hans Franke <Hans.Franke_at_mch20.sbs.de> wrote:
> > On Tue, 19 Mar 2002, Ben Franchuk wrote:
> > > Glen Goodwin wrote:
> > > > 1 -- Build an interface for every device under the sun, including
> > > > the toilet seat.
> > > 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...
> > counting total turns, comparing against approximate turns-to-roll-
> > exhaustion, and...printing out a TP-LO Warning.
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...
for low velocities, there must be lots of paper (when the roll is full,
3 squares per second produces, say, 1/60 RPM; but when the roll is nearly
empty, the same linear pull rate produces 1/20 RPM - kinda the opposite
of linear bit-density calculations on variable zone recording floppies
and hard disks). There's probably a way to embed an inertial sensor in
the holder to measure the force it takes to start the roll moving... the
possibilities are endless!
> Isn't using a PDP-11 as perhipheral processor for a ZX81
> a bit out of scope ?
Nah! You shoulda been at Lucent when a 3rd-shift factory worker rebooted
the $500,000 Fujitsu SMT part placer so he could surf the web on the
attached 486 that ran a windows app to display the parts and their
orientation. A full production line halted so a blue-collar guy could
go check out EPSN. No kidding. But it was a union shop - all he got
was a written reprimand.
The point is, who says the peripherals have to be less powerful than the
core? Our original COMBOARD was an 8MHz 68000 sitting on the Unibus
of a PDP-11 - the serial card had more horsepower than the machine it
was mounted in (one way it got used: we had our own dataproducts port
so we could spool jobs from the IBM right to a printer, relieving the
burden on the, typically, RSTS print spooler).
-ethan
__________________________________________________
Do You Yahoo!?
Yahoo! Sports - live college hoops coverage
http://sports.yahoo.com/
Received on Wed Mar 20 2002 - 11:34:01 GMT