PDP/8 on a chip implementation (Scott's post)

Stan Barr stanb at dial.pipex.com
Wed Mar 9 03:09:53 CST 2005


Hi,

Ethan Dicks said:
> On Tue, 08 Mar 2005 19:22:35 -0700, woodelf <bfranchuk at jetnet.ab.ca> wrote:
> > Well this looks snazzy ...  On topic too... 'Dark room timer'
> > 
> > > http://artm-friends.at/rm/foto/duka.html
> 
> Is that an Intercept Jr?  Sure looks like it.  Handy that LEDs don't
> fog paper.  :-)
> 
> It reminds me of an article I saw, with software, for hanging a relay
> off of the Q-line of an 1802 on an original PopTronics Elf for use as
> an enlarger timer.  You set the time on the toggles, fired up the CPU,
> and used the IN button to fire the enlarger for a preset number of
> seconds.
> 
> Given how much enlarger timers were 30 years ago, this was an
> effective use of a $100 computer.  Kinda still is.

They _were_ expensive back then, being a hardware type I built my own
about 25 years ago.  It divided the 50Hz mains frequency down to 1 Hz 
and fed that to a pair of bcd counters with the count set by thumb-wheel
switches (with a red led to illuminate them...).  It's still in use 
controlling my Americam-made Omega emlarger of the same vintage.

-- 
Cheers,
Stan Barr  stanb at dial.pipex.com

The future was never like this!





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