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Rating 8-bit Video Output Quality

Posted: Thu Jan 15, 2015 10:02 pm
by Great Hierophant
If I had to rate the various official NES and Famicom variants by picture quality without any modifications, I would rate the systems as follows :

1 Famicom Titler - Supports S-Video, but uses RGB 2C03/2C05 CPU, leading to some incompatibilities.
2. Famicom AV - Supports Composite Video output, no jailbars can be seen
3. NES Front Loader, probably the Sharp NES/Famicom TVs, maybe the Twin Famicom - minor jailbars can be seen occasionally, if you know what to look for.
4. NES Top Loader and probably original Famicom - RF only, prominent jailbars.

Can anyone shed more light on the Japanese consoles (except for the Famicom AV)?

Re: Rating 8-bit Video Output Quality

Posted: Fri Jan 16, 2015 6:42 am
by tepples
See also ccovell's I want my RGB

Re: Rating 8-bit Video Output Quality

Posted: Sat Jan 17, 2015 12:55 am
by Memblers
If anyone is curious about the Playchoice, it probably has worse jailbars than the top loader (going by my impression, I haven't done a side-by-side comparison).

Re: Rating 8-bit Video Output Quality

Posted: Tue Jan 20, 2015 9:50 pm
by mikejmoffitt
I was playing a VS SMB cabinet the other day, and jailbars were very faint but present. Substantially less than the NES toploader or an AV modded original Famicom, but they were there a little.

Re: Rating 8-bit Video Output Quality

Posted: Wed Jan 21, 2015 8:06 am
by Great Hierophant
One downside here is that the comparison of a top loader or original Famicom is affected by the RF output. A basic AV mod will show prominent jailbars, but judging by the NES and the Twin Famicom, if Nintendo wanted AV output in these RF-only systems, it would have used a less noisy video path.

Re: Rating 8-bit Video Output Quality

Posted: Wed Jan 21, 2015 9:41 am
by rainwarrior
The strength of the jailbars seems to vary somewhat randomly from machine to machine, so far as I've seen with Famicom AV mods anyway. I don't know if a jailbar comparison is fair unless you're comparing several of each type.

Re: Rating 8-bit Video Output Quality

Posted: Wed Jan 21, 2015 4:50 pm
by koitsu
Devices I own or have owned (I recently gave my Famicom away, but I distinctly remember its visual quality), none of which are modified:

* Famicom
* Famicom AV (still have this), hooked up via AV
* NES front-loader (still have this), hooked up via AV
* NES top-loader (still have this)

The Famicom AV and NES front-loader have the best visual output -- no "jailbars" (vertical banding). My Famicom's RF output was noisy (like all RF is), but I do not remember seeing excessive "jailbars"; if they were there, they were very subtle. How do I know that? Because my NES top-loader has awful "jailbars" (and is also RF, remember) -- definitely the worst of the bunch.

I should note I only have one TV set, and I only have one device hooked up to the TV at once. I do not use any kind of A/V switchbox, so the connects are all direct with no intermediary devices (i.e. console <--> TV).

If you need to know what exact the serial number is on the Famicom (original) that I gave away, I can get it (I know the guy who I gave it to), in case you're trying to determine if "excessive banding" began on the Famicom as of a specific S/N or not. But IMO it's not worth the effort. There's already a Japanese website where a guy went to town redoing the A/V path on his Famicom to clean it up and got amazing results (I can dig up the links, but I've posted in threads here about them before). If people want those page translated into English I can have it done by my neighbour (who does professional Japanese/English translation for Nokia), but it will very likely cost money because of the massive amount of text.

Re: Rating 8-bit Video Output Quality

Posted: Wed Jan 21, 2015 8:35 pm
by Great Hierophant
koitsu wrote:Devices I own or have owned (I recently gave my Famicom away, but I distinctly remember its visual quality), none of which are modified:

* Famicom
* Famicom AV (still have this), hooked up via AV
* NES front-loader (still have this), hooked up via AV
* NES top-loader (still have this)

The Famicom AV and NES front-loader have the best visual output -- no "jailbars" (vertical banding). My Famicom's RF output was noisy (like all RF is), but I do not remember seeing excessive "jailbars"; if they were there, they were very subtle. How do I know that? Because my NES top-loader has awful "jailbars" (and is also RF, remember) -- definitely the worst of the bunch.

I should note I only have one TV set, and I only have one device hooked up to the TV at once. I do not use any kind of A/V switchbox, so the connects are all direct with no intermediary devices (i.e. console <--> TV).

If you need to know what exact the serial number is on the Famicom (original) that I gave away, I can get it (I know the guy who I gave it to), in case you're trying to determine if "excessive banding" began on the Famicom as of a specific S/N or not. But IMO it's not worth the effort. There's already a Japanese website where a guy went to town redoing the A/V path on his Famicom to clean it up and got amazing results (I can dig up the links, but I've posted in threads here about them before). If people want those page translated into English I can have it done by my neighbour (who does professional Japanese/English translation for Nokia), but it will very likely cost money because of the massive amount of text.
Can you recall whether your Famicom was an early or later model?

It seems like there is little difference, in terms of board workings, between the later Famicoms and the Top Loader. The obvious stuff like the port differences aside, the chips are the same and their layout appears to be virtually the same.

Re: Rating 8-bit Video Output Quality

Posted: Wed Jan 21, 2015 10:05 pm
by koitsu
What defines "early" vs. "later"? There's no manufacturing dates on them, only a serial number. And I have no idea if my Famicom (prior to me owning it, because I got it off eBay 12+ years ago) had its mainboard swapped out (something I've seen many people do, and not just with Famicoms -- they get two identical consoles and swap out the parts to make one that's working/visually pristine/whatever). All I could go off of was the serial number, hence my last paragraph.

With regards to the NES top-loader, I remember reading (likely here on nesdev) that there were some super late-revision models which had completely reengineered motherboards which did not suffer from the "jailbar" effect, and that for a short while after they were released, you could send your top-loader to Nintendo (complaining about the problem) and they'd replace the board. I think someone somewhere had pictures of the different mainboards, but it's been a while...

Re: Rating 8-bit Video Output Quality

Posted: Thu Jan 22, 2015 2:05 pm
by Great Hierophant
koitsu wrote:What defines "early" vs. "later"? There's no manufacturing dates on them, only a serial number. And I have no idea if my Famicom (prior to me owning it, because I got it off eBay 12+ years ago) had its mainboard swapped out (something I've seen many people do, and not just with Famicoms -- they get two identical consoles and swap out the parts to make one that's working/visually pristine/whatever). All I could go off of was the serial number, hence my last paragraph.

With regards to the NES top-loader, I remember reading (likely here on nesdev) that there were some super late-revision models which had completely reengineered motherboards which did not suffer from the "jailbar" effect, and that for a short while after they were released, you could send your top-loader to Nintendo (complaining about the problem) and they'd replace the board. I think someone somewhere had pictures of the different mainboards, but it's been a while...
I am not 100% sure my definition would be or is universally accepted, I classify Famicoms into four categories:

1. The Square Button Famicom, which uses the HVC-CPU board up to and including revision 06. The early boards formed the recall and tend not to be the most reliable. They have the AV board connected to the main board via a ribbon cable. The red bottom of the case has a glossy finish.

2. The Round Button Famicom HVC, these have the HVC-CPU 05-08 revisions, and have the AV board connected to the main board via a ribbon cable. The red bottom of the case usually has a matte finish. There is overlap between the square and round button famicoms when it comes to the HVC-CPU-05 and 06 revisions.

3. The Round Button Famicom GPM, these have the HVC-GPM boards, tend to be more reliable and have the AV board soldered to the main board via the shield. They always have a matte finish to the bottom shell. Apparently these will show less noticeable jailbars than the HVC boards after modding : http://jpx72.detailne.sk/modd_files/fc/avmod.htm

4. The Famicom AV

Game-Tech has some pictures and a video of a Nintendo-fixed RF output NES Top Loader, as you can see, the internals are almost identical to a Famicom AV (but apparently still accepts AC input.) http://www.game-tech.us/pmwiki/pmwiki.p ... S-101Intro

I am positive that an Nintendo Top Loader AV version exists, this guy posted a video about it :

https://www.youtube.com/watch?v=mEhNt5q7Hl0

It uses the Nintendo Multi-Out. It's backplane refers to the power jack as DC IN where other Top Loaders say AC ADAPTER, but it has a bridge rectifier on it, so I believe it uses the standard NES-002 brick.

Re: Rating 8-bit Video Output Quality

Posted: Thu Jan 22, 2015 7:25 pm
by mikejmoffitt
Great Hierophant wrote: I am not 100% sure my definition would be or is universally accepted, I classify Famicoms into four categories:

1. The Square Button Famicom, which uses the HVC-CPU board up to and including revision 05. These formed the recall and tend not to be the most reliable.
Eh, not quite right - I got a square button Famicom and it had this guy:

Image

How about those SMT RAM chips? The screws made that fresh "never been opened" sound, so I'm fairly confident this is the original PCB. It has the revisionless 2A03 with the missing noise loop bit.

Re: Rating 8-bit Video Output Quality

Posted: Thu Jan 22, 2015 11:41 pm
by Great Hierophant
Apparently the CPU-HVC-06 boards come in square and round button varieties : http://famicomworld.com/workshop/tech/s ... n-famicom/

It is hard to see, but that board has a 2A03E CPU.