9915A in a blinking decorative lights display

[Tony Duell]

> 
> http://www.series80.org/HP-9915A/blinkenlichts.html

Yes, I saw it when you posted a message about it to MoHPC.

A few years back I ran my Newtonsday [1] lights from a PERQ PERQlink 
port. Just buffered the data output lines and fed them to LEDs. A bit of 
pascal to produce the patterns and a bit of microcode to write values to 
the port completed the project.

Somewhat more recently I wrote a Datafile (HPCC club magazine) article of 
HP calculator controled Nwetonsday lights, using either an HP41 + HPIL + 
GPIO interface or an HP48 + ARD's I2C interface. HPCC can probably 
provide copies of that article for anyone who's mad enough to want to try it.

I also know of somebody who patched RT11 to write the idle lights display 
not to the switch register address but to the address of a 'spare' DR11 
card. The output of that was buffered and used to flash 16 LEDs aranged 
in sone tinsel around the top of the rack.

[1] As an agnostic I see no particular reason to celebrate Christmas. As 
a physicist I see a good reason to celebrate the birthday of Sir Isaac 
Newton. He was born 25/12/1642

-tony