Neo RGB/Video Part 2: The details!

Well, it took a few hours, but I got it done: the complete diagram of differences between the old and new Neo Geo hardware.

<a href="http://nfg.2y.net/games/neorgb2" target="_blank">http://nfg.2y.net/games/neorgb2</a> <- have a look.

If you have any insights or notice any errors, please let me know!

<small>[ July 31, 2003, 10:48 AM: Message edited by: NEOGEOman ]</small>

That is how I modified my old Neo for better RGB, through that 6.8k resistor, bypassing the encoder/resistors and wiring them up to the 8 pin din socket. Way nicer picture, like an MVS board.

<small>[ July 31, 2003, 07:28 PM: Message edited by: Devilman78 ]</small>

This is an AWESOME work NEOGEOman. buttrock
You have all my respect.

Anyway, what I was thinking is: modding and older version with an rgb bypass of 'output encoder + resistor) should result in the best picture avalaible maybe?

I mean, if the only 'minus' of the older revision is a slightly darker RGB (but way sharper and cleaner), getting rid of the final encoder+resistor should lead to a slightly stonger RGB signal, thus briter I think.

What do you think?

G.

I haven't done any testing on the what-ifs yet, I'm in the middle of a house move. I should be able to get around to this in a week or three.

If you bypass all the output resistors you'll end up with same-as-MVS output, which is too bright for many applications.

Maybe it's just me, but I think I found a little flaw in your diagrams for 'post encoder RGB output'.

The diagram have 'RGB' as for the input and 'to sony chip' as for the outputs.

But if this is the POST encoder scheme, the output shouln't lead to DIN-8?


I was thinking the whole thing is:

NeoGeo CPU
||
64k VRAM
||
8bit latch
||
1st resistor group
||
Sony Composite Encoder chip
||
2nd resistor group
||
DIN-8 multi-video out


Following this diagram (if correct), maybe the more logical option to have best quality RGB on standard RGB-tv whould be to bypass just the Encoder Chip and the following second group con resistors, while NOT bypassing the first grouop of resistor...

maybe.

Fixed, thanks for noticing.

maybe the more logical option to have best quality RGB on standard RGB-tv whould be to bypass just the Encoder Chip and the following second group con resistors, while NOT bypassing the first grouop of resistor.

Click to expand...

Maybe. Give it a try both ways. Just remember to disconnect the components after your new signal tap. If you leave the encoder plugged into your RGB it'll suck the life out of your signals.

NEOGEOman

maybe the more logical option to have best quality RGB on standard RGB-tv whould be to bypass just the Encoder Chip and the following second group con resistors, while NOT bypassing the first grouop of resistor.

Click to expand...

Maybe. Give it a try both ways. Just remember to disconnect the components after your new signal tap. If you leave the encoder plugged into your RGB it'll suck the life out of your signals.

Click to expand...

Yeah. But, do you actually believe the encoder itself, as for allowing composite video, also slightly degrade (filter?) RGB signal?

<small>[ August 01, 2003, 10:59 AM: Message edited by: Shito ]</small>

It's possible, if the other componenets generated feedback or something. I've not done any testing.

NEOGEOman:
It's possible, if the other componenets generated feedback or something. I've not done any testing.

Click to expand...

Thank you for the much appreciated opinions and good work.

Also, allow me to say the whole page/site you're RGB analysis is contained rocks hard!

Great interesting topics about gaming hardware and nice colums of information. buttrock

Gotta love that.

I should point out there are two changes I need to make to that page. Both the highest and lowest resistors are NOT used in the same fashion - instead they're tied together and seemed to be used to brighten or darken all three colours at once. I'll be posting details in ~2 days after I finish moving.