15.7 KHz RGBs to Component (YPbPr) schematic/IC?

[Richard Crowley]

"Jerry Lynds" wrote ...

It just has 3 RCA connectors labeled Y, Pb and Pr. I am assuming sync
is on the Y...as this circuit to convert from Component (YPbPr) to RGB
uses a LM1881 to remove the sync from Y

Yes, likely sync on Y.
But you don't want to *strip* the sync, you want to do
the opposite, to ADD the sync.

You already have the composite sync available to use on
the separate pin from the source equipment. You just need
a quite simple circuit to impose the H and V sync pulses
onto the Y video signal. The circuits I've seen for this
have used a single transistor and 3-4 resistors.

I think this is starting to be more trouble than it is worth...

No, I think you're nearly done.

 

[joseph2k]

"Jerry Lynds" wrote ...

Yes, likely sync on Y.
But you don't want to *strip* the sync, you want to do
the opposite, to ADD the sync.

You already have the composite sync available to use on
the separate pin from the source equipment. You just need
a quite simple circuit to impose the H and V sync pulses
onto the Y video signal. The circuits I've seen for this
have used a single transistor and 3-4 resistors.


No, I think you're nearly done.

I will make a suggestion now. Take your existing cable that fed the
Commodore monitor, and feed that into the silicon chip box or equivalent,
and feed that to the new TV and you are done.

 

[Jan Panteltje]

Thanks Jan. It's about a monochrome display mainly used for 80 columns
characters and only two steps of brightness except black.

Hi Petrus,
80 characters on a TV like screen is difficult to read, 40 works fine.
If the characters are 8 pixels width, you have 640 samples in about 60 us.

It can do graphics
as every dot is programmable but it is slow. So AD will be overkill. I think
some comparators will do. Problem may be how to synchronise the sampler with
the dotclock. If you have material about the storage and recovery of the
samples and the way you treated the sync I should be glad to receive it.

BTW My e-mail address is valid once you've removed the obvious additions.
Petrusdotbitbyterathotmaildotcom works as well.

petrus bitbyter

OK, check your mail at hccdotnet.
It has some verilog code, and a link to diagrams.

 

[petrus bitbyter]

On a sunny day (Fri, 27 Oct 2006 22:37:21 +0200) it happened "petrus
bitbyter"


Hi Petrus,
80 characters on a TV like screen is difficult to read, 40 works fine.
If the characters are 8 pixels width, you have 640 samples in about 60 us.



OK, check your mail at hccdotnet.
It has some verilog code, and a link to diagrams.

Got it, thanks.

petrus bitbyter