Log in

View Full Version : Genesis video output



The Manimal
10-27-2004, 11:13 AM
Any reason as to why the Genesis 1 has a much softer/less sharp image than the Genesis 2 even though (from what I understand) has the same video chip? Granted I was playing around with these last night, and I like how the Genesis 1 doesn't seem to make everything look pixelated (? not sure what word to use) with the softer image, but I tried playing TECMO SUPER BOWL and the players BLURRED on the screen. Just looked terrible. I switch over to the Genesis 2 and the blurriness is not there, and it's brighter a tad plus it's very sharp and pixelated (again, not sure what term to use). If I remember correct, the Genesis 3 continues in this pattern. Granted in all cases they were using composite output, but it makes me wonder if those online 'mods' for the Genesis 1 with S-Video output only make it look like the Genesis 2 does with composite?

Gamereviewgod
10-27-2004, 11:44 AM
M Genny 1 with S-video is fantastic. Fabomjoy here on the boards did a fantastic job. Can't really compare it to a Gen. 2 with composite, but trust me that it makes a world of difference.

The Manimal
10-27-2004, 12:01 PM
M Genny 1 with S-video is fantastic. Fabomjoy here on the boards did a fantastic job. Can't really compare it to a Gen. 2 with composite, but trust me that it makes a world of difference.


I think there's a world of difference between the composite out of the Genny1 and 2... :)


Hope to hear the answers. For the given time, I like the Gen 2 better, though the softer image looks better on colored text on the screen.

Melf
10-27-2004, 01:18 PM
I have an s-video modded Genny 2 and it looks great.

FABombjoy
10-27-2004, 01:34 PM
Sega seemed to make some revisions to their implementation of the CXA1145 as the model 1 Genesis was in production, probably to sharpen up the composite signal. Also, not all Genesis 2 units use the same chip; some use a Samsung RGB encoder instead (I think Samsung... have the datasheet at home). The Samsung Gen2s can't be easily modded for s-video.

An s-video Gen1 looks much better than a composite Gen 2. I have them running side by side and there's a noticeable difference. The early model, non lockout Gen 1 units take to s-video really, really well.

The Neo Geo uses the same CXA1145 chip, and as they made revisions to the circuit to improve the quality of the composite, the quality of the s-video mod dropped slightly.

The Manimal
10-27-2004, 01:58 PM
The Genesis 1 I tested was the non-lockout version...

Where do you look inside for the Samsung encoder (or the prior chip) inside of the Genny 2? I need to take it apart again (I need to replace the rubber piece under the RESET button...anyone have an extra of this? I'm willing to pay a dollar plus shipping (sorry for sounding cheap, but granted how much Genny's go in the 'wild' plus this is just one rubber piece of it..)


Perhaps I should try and have one of my Genny 2's modded (if they can)? Then again, if I use it with my 32 it would not probably work. I wonder if there's an S-Video mod for 32X?

I have:

Genesis (version 1) non-lockout w/ EXT X 1
Genesis (version 1) lockout w/o EXT X 1
Genesis (version 2) not sure X 2
Genesis 3 X 3

I need to get rid of some of those 3's... LOL

FABombjoy
10-27-2004, 04:05 PM
Where do you look inside for the Samsung encoder (or the prior chip) inside of the Genny 2?

Should be near the a/v connector port. A Samsung part has a big S on it. I think it's a 20xx series chip or something. The Sony part will be a CXA series, and say Sony on it.


Perhaps I should try and have one of my Genny 2's modded (if they can)? Then again, if I use it with my 32 it would not probably work. I wonder if there's an S-Video mod for 32X?

32x isn't compatible with s-video mods, unfortunately. The chips inside are all Sega branded parts... I probed around a bit once and didn't come up with any usable signals, but I may have missed something.

The Manimal
10-27-2004, 05:19 PM
Where do you look inside for the Samsung encoder (or the prior chip) inside of the Genny 2?

Should be near the a/v connector port. A Samsung part has a big S on it. I think it's a 20xx series chip or something. The Sony part will be a CXA series, and say Sony on it.


Perhaps I should try and have one of my Genny 2's modded (if they can)? Then again, if I use it with my 32 it would not probably work. I wonder if there's an S-Video mod for 32X?

32x isn't compatible with s-video mods, unfortunately. The chips inside are all Sega branded parts... I probed around a bit once and didn't come up with any usable signals, but I may have missed something.


I will look right now...

The Manimal
10-27-2004, 05:48 PM
I just looked. Unless this is from the bottom view of the MOBO (which I do not know how to get off the casing!), I can't find either. With the console facing me, I see the Motorola CPU on the top right, and in the center another chip which has around 40 pins, which doesn't say what you describe, and then one on the top left about 3/4 of the size of the one in the middle, which just says SEC A622; KA2195D on it. The date on the MOBO says 08 AUG 1996...


Also...



Also gen3s (and late model gen2s) can be easily modified for s-video output.
Gen1s can also do s-video after a more complicated mod.
And sometime soon, I'm going to investigate the compatiblity problems on a
gen3 and nomad. People always talk about the consolidated chip set, but the cdx also has this and it works with the pbc and 32x.
John
[/url]

This says the later version 2's can be modded to S-Video? @_@

FABombjoy
10-27-2004, 08:02 PM
KA2195D - That's the Samsung RGB encoder. It has no Y/C signal available for the mod.

You should be able to mod any Genesis that has a CXA1145 or CXA1645 chip. The 1645 is supposed to support s-video without additional circuits. Never tried it myself. I think that's what the Gen3 is supposed to have, and possibly the later model Gen2s.

The Manimal
10-27-2004, 08:55 PM
Damn! :(

Anyways, I went ahead opening up and noting some things between the consoles..perhaps some of this is useful to someone


My Genesis 1 w/o lockout and w/ EXT port's serial number starts with NUMBERS (39T42335), and the Genesis LOGO is half-WHITE, half-GRAY.

My other Genesis 1 w/ lockout and w/o EXT port's serial number starts with two LETTERS (GT0061245), and the Genesis LOGO is one solid color...LIGHT GRAY.

My Genesis 3 DOES have a CXA1645.

My one Genesis 2 says VA 1 on the mobo (dated 1993 - serial 130412886), and the GENESIS and SEGA logos are both a dull white color. This DOES have a large "S" on the chip you said to look for.

The mobo of the Genesis 2 I mentioned earlier says VA 3 on it (dated 1996 - serial 163179916), and the SEGA and GENESIS logo's are both in a DARK GRAY unlike the earlier dated unit (a darker gray on a black casing looks MUCH less ugly IMO than that dull white on black after doing a side-by-side comparison). Also, the mobo is arranged differently and some chips are of different sizes and with different markings on them, so I assume this is a third variation of the Genesis 2 "guts".


Besides this, I did a video output comparison between all my Genesis's (well, except for two of my Genny 3's) with CASTLEVANIA and noted one thing. The 'white' "ENEMY" life bar (which is empty unless you are facing a boss) had a 'rainbow' appearance to it on both Genesis 1's, the Genesis 3, and the 1993 Genesis 2. Strangely, on the 1996 Genesis 2, there was no 'rainbow' appearance to the life bar at all...it was solid white throughout. I have no idea/reason for this other than noting it...too bad this has to be the unit where the RESET button only works if you press it 20 times (i noticed the piece is soldered to the board :( )

The Manimal
10-28-2004, 02:44 PM
one bump since i typed all that info out LOL