gbell@pnet12.cts.com (Greg Bell) (09/06/89)
I'm looking to use my TV as a display for my 8031 microcontroller circuit. I
know how to take a video signal and modulate it into something the TV can use
(using National's LM1889 or LM2889).
So, now I need a video generator. I need something that can take in character
postion/values or whatever, and generate a video output that I can feed into
the modulator. Need not have color/sound etc.
The only chip I've looked at so far is Intel's 8745 CRT controller. But, this
, as it says, is a CRT controller and doesn't seem to output video readily...
or am I missing something?
Are the other CRT controllers (6845 etc) able to generate a composite video
signal? Is it a composite signal that I need to modulate for the TV????
Please E-Mail me any responses and I will summarize and post the answers...
PS. Can somebody E-Mail me the recent discussion on digitizing voice using
1-bit circuits?
Greg Bell_________________________________________________________
Hardware hacker |
Electronics hobbyist | UUCP: uunet!serene!pnet12!gbell
EE major at UC San Diego |dya@unccvax.UUCP (York David Anthony @ WKTD, Wilmington, NC) (09/06/89)
In article <914@serene.UUCP>, gbell@pnet12.cts.com (Greg Bell) writes: > I'm looking to use my TV as a display for my 8031 microcontroller circuit. I > The only chip I've looked at so far is Intel's 8745 CRT controller. But, this > , as it says, is a CRT controller and doesn't seem to output video readily... > or am I missing something? I've never heard of the 8745, (work in a Motorola shop) but a chip like the 8276H (page 6-32 of the 1988 Intel Perhipherals book) is probably similar. All of these chips have outputs like /HRTC and /VRTC, which you can simply logically AND (or OR, depending on the sense) to obtain your sync signal; and /VSP, which you use as blanking. The output of the dot clock shift register you then use as the video signal for modulation. Surely someone makes (by now) a cheap CRT controller with a built - in character ROM? Forget the 6845; who needs to try and get Motorola stuff to play on the Intel bus? York David Anthony DataSpan, Inc
eegauthe@cybaswan.UUCP (o) (09/07/89)
In article <1642@unccvax.UUCP> dya@unccvax.UUCP (York David Anthony @ WKTD, Wilmington, NC) writes: >In article <914@serene.UUCP>, gbell@pnet12.cts.com (Greg Bell) writes: > >> I'm looking to use my TV as a display for my 8031 microcontroller circuit. I > > Forget the 6845; who needs to try and get Motorola stuff to play on the >Intel bus? Intel Bus for Motorola chips? :-) Might be a good mnemonic! Olivier. -- Olivier GAUTHEROT,// Postgraduate // Electrical Engineering Dept. University of Wales // Swansea, SA2 8PP, U.K. (+44 792 205678 ext 4564) UUCP : ...!ukc!pyr.swan.ac.uk!eegauthe JANET : eegauthe@uk.ac.swan.pyr "A lovely girl in a hammock is a hanging garden." A. Allais
gbell@pnet12.cts.com (Greg Bell) (09/08/89)
>> The only chip I've looked at so far is Intel's 8745 CRT controller. But, this > > I've never heard of the 8745, (work in a Motorola shop) but a chip like >the 8276H (page 6-32 of the 1988 Intel Perhipherals book) is probably similar. Whoops... yep, the 8276H is what I was thinking of. The idea of having to have an external character ROM was a bit discouraging.... >All of these chips have outputs like /HRTC and /VRTC, which you can simply logically >AND (or OR, depending on the sense) to obtain your sync signal; and /VSP, which you >use as blanking. The output of the dot clock shift register you then use as the >video signal for modulation. > Thanks for the info. Now that I know its possible to use the 8745, I'll take a closer look at the databook. > Surely someone makes (by now) a cheap CRT controller with a built - in >character ROM? You're probably right... looking through the Jameco catalog, I spotted several $20+ controllers that must have some nice features. Greg Bell_________________________________________________________ Hardware hacker | Electronics hobbyist | UUCP: uunet!serene!pnet12!gbell EE major at UC San Diego |