Panda Display USB support in klh10 working

Mike Ross tmfdmike at
Sun Jan 3 19:50:45 CST 2016

Well if you decide to produce it - as a kit of parts or a finished
product! - put me on the list; I'll take two or three of them. Email
me direct if you like.


On Mon, Jan 4, 2016 at 10:06 AM, David Griffith <dave at> wrote:
> On Mon, 4 Jan 2016, Mike Ross wrote:
>> On Sun, Jan 3, 2016 at 8:43 PM, David Griffith <dave at> wrote:
>>> I've managed to edit klh10 to talk to my new USB Panda Display
>> *blinks*
>> There's a USB Panda display?
>> I bought two of the original parallel port Panda displays years ago.
>> Recently wasted a lot of time trying to get them to work. The Windows
>> diagnostic tool program works perfectly - sending patterns to lights
>> and running them. But try to use them with klh and they initialize
>> with a few random lights on when you start it and then never change at
>> any point until *hardware* power is cycled. Evidently there's
>> something screwy and the support for them was never actually
>> incorporated into klh and/or the final Panda TOPS-20 release.
> One of the big limitations of the original Panda Display is that the
> parallel port is accessed through IO ports, not the operating system.
> Because of that, a USB-to-parallel converter will not work.  I also got one
> of the original displays.  By the time I built it up, I didn't have easy
> access to a real parallel port.  That's when I started to design a USB-based
> display.  The hardware and firmware is fairly simple.  The klh10 side of it
> is more complicated.
> --
> David Griffith
> dave at
> A: Because it fouls the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing in e-mail?

'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'

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