Re: Keyboard and Video interfacing


Abstract Dissonance wrote:
I was thinking about trying to do a project that involves a PC keyboard(and
maybe mouse) and possibly a PC video monitor.

Can someone point me in the right direction to get started? I'd like
basicaly to "sense" or "transform" information between the data paths of the
pc and these devices... the keyboard one is sorta like a data logger type of
thing but actually is something else.

I'm sure the PS/2 port for the keyboard/mouse is very easy to handle but
what I'm woried about is for USB keyboards... not sure if the protocol is
standardized... if so then it should be pretty easy to interface using a PIC
that supports USB?

What kinda signals come out from the graphics card to the video monitor? I
assume there are both analog and digital outputs since I've seen newer
graphics cards with D/V out. Would it be relatively easy to "sample" the
video output of a graphics card and transform it then sent it along its way
to the monitor?


(I'm more interested in doing this in hardware than software)

Thanks for any info,
Jon

Hi, Jon. By far the easiest way to interface between a modern keyboard
and a modern momitor is to put a PC between them.

Having said that, doing some things the old fashioned way can be
educational. If you really want to do something like this, I'd
recommend finding an old copy of Don Lancaster's "TV Typewriter
Cookbook". It's a serious hobbyist-level book which shows how to
interface a parallel input keyboard with a television, to show letters
and characters on screen. If you can't scrounge a copy, they're
available used from Amazon for a few bucks:

http://www.amazon.com/gp/product/0672213133/104-1780992-3603126?n=283155

Look at the book carefully, because you're going to have to make some
serious mods. The PROMs and some of the analog components in the book
are obsolete (I think it's been 30 years), but you can work out
substitutions. Go figure -- you may be the only person on the face of
the earth trying to do this.

Seriously, though, it would be really educational, and I would guess
Don might be interested in hearing about your work. His website is:

http://www.tinaja.com

Another thing you might want to try is finding an old VT-100 terminal,
and using a PIC to translate keypad inputs into RS-232 serial
characters to send to the terminal screen. You might be able to do
some curious things with ANSI-type graphics.

But interfacing a PC keyboard to a VGA display would basically be
recreating the PC keyboard interface with whatever processor you want
in the middle, and a VGA card from scratch. You should be able to get
a PIC to interface with a keyboard (the AT keyboard interface is
serial), but you need a lot more than a PIC to control a VGA card, and
the VGA card itself would be a major engineering effort. This isn't
realistic.

Good luck
Chris

.

Relevant Pages

  • Re: Keyboard and Video interfacing
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  • Keyboard and Video interfacing
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    (sci.electronics.basics)
  • Re: Keyboard and Video interfacing
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