Best PlayStation 1 model?

5xxx is better than 7xxx

Either use RGB or do the colour mod (to force PAL all the time). there is no reason to get a 7xxx with its (slightly) inferior picture quality.

 

SCPH-1001 seems to have the best RGB video quality in my experience, though I haven't thoroughly tested it. My SCPH-1001 seems to take a bit longer than it should to load discs sometimes, but it's still fully functional. It's never been repaired or modified to my knowledge. Also, as I'm sure most people are already aware, the SCPH-1001 makes a pretty good CD player. Perhaps not as good as some people claim, but still pretty good.

 

The NTSC part seems to be custom, but I did get the PAL version from Mouser - but I just checked, and they are now out of stock.

http://hk.mouser.com/ProductDetail/...k7wiZ4jNTViIS/K3%2bCCgO4QSUNeY/ZLDsTYrAs3DQ==

You could also order something like this and get them to program the correct frequency into it.

http://www.digikey.com/product-detail/en/CPPC7-LT5RP/CPPC7-LT5RP-ND/387885

I wouldn't recommend using programmable oscillators on the old (PU-7, PU-8, PU-18) boards, though - they tend to have significantly higher levels of phase noise than the fixed-frequency ones and on those old boards the color subcarrier is generated by the GPU by dividing down the reference oscillator so using a noisy clock source will give you a noisy subcarrier reference and hence chroma noise (this is likely the reason that the subcarrier is taken directly from the clock synthesizer on the newer boards).

If you have one of the later PU-8 boards, the board has the pads for both oscillators on it - so if you install the missing one along with it's associated components (and remove the 0 ohm link on the back of the board) then it will generate correct video signals in both PAL and NTSC mode. This is how the Yaroze was set up.

 

Yea, I wanted to do that. I happen to have one of these PU-8's (PU-8 1-658-467-21 built in "3 96" based on the additional serial number on the underside ).
So I'll try to get a couple NTSC consoles for this project then.

 

http://i.imgur.com/pSOObcx.jpg

It works, apparently. Still need to fix the broken laser gain pot on the unit but I had color in both video modes via composite.
Excuse the look but yeah, this stuff is really tiny

 

Yeah, it's much easier to solder those things with hot air. You probably noticed this, but there is also a decoupling cap on the back of the NTSC board near where the 0-ohm link was - it will work without it, but the signal is cleaner if you install it. It also looks like you used the 0-ohm link to connect the oscillator power - that's normally a ferrite bead (part of the supply filter, along with the cap on the back of the board).

 

I was all out of ferrite beads and I didn't care about the filter cap on the back (yet)
So far it was just to see if it works and yep, it does work.
There's no issues with the NTSC mode from what I could tell.

The console gets a bit too warm for my taste. I'm used to the more efficient later models.
I'll have to look into some changes for this problem or it'll kill my lasers

 

So I checked the underside of my board and the decoupling cap was already installed. It's missing the green component (0 Ohm resistor?) that I can see on your earlier picture though.

Yours:

And mine:

Is that the bypass for the NTSC oscillator when "switching to PAL mode"?

 

Yeah, I probably should have made that a little clearer.

On the GPU, the primary clock is the one used for NTSC, and the PAL clock is only needed if you are going to be generating PAL signals. So what Sony did was set the board up so that in NTSC mode the NTSC clock input gets 53.69MHz and the PAL input is connected to ground (that's what the link on the right does) - in PAL mode, both clock inputs get 53.20MHz (that's what the link in the middle does). Basically, there will be a link in one of two positions on the board depending on if it was built for PAL or NTSC - but no matter what position it's in, you have to remove it.

So your board is correct.

It's interesting that it already had that cap installed - the later PAL PU-8s didn't (presumably because someone at Sony realized that it wasn't connected to anything so there was no point in installing it...).

 

Yep, that's it. I found another PAL PU-8, this time a 1-658-467-23.
It has the a newer GPU I think (there's an extra B in the name now) and the cap was not installed on it.
The one I modded is a -21 with the older GPU. It's working great in PAL and NTSC

 

Could one simply solder in an IO port into a SCPH-9001 board? I have one that looks the same as my SCPH-7501 but without the IO connection.

 

If this is correct information then I'm extremely happy that my MM3 modded machine is a SCPH-5552.

 

It is correct information,except I got the model of the Sega wrong:it's Genesis 3,not CDX.
Here's a picture which shows that the 55xx (and 100x too)have the same video encoder chip as the Genesis 3.

 

The bit about the video encoder is right, but a SCPH-5502/5552 still doesn't generate 100% correct NTSC signals because the reference clock is wrong.

The PAL consoles use a 53.20MHz oscillator and the NTSC ones use a 53.693MHz oscillator. Normally (I.E in PAL mode) the GPU divides the reference clock by 12 to give you 4.433333.. MHz - which is almost exactly the PAL subcarrier frequency. On the NTSC consoles, the reference clock is divided by 15 to give you 3.5795333..MHz - which is almost exactly the NTSC subcarrier frequency.

If you put a PAL console into NTSC mode, it still uses the PAL (53.20MHz) reference osc, but divides it by 15 - giving you 3.5466666...MHz, which is about 30kHz off frequency. The NTSC spec calls for a frequency accuracy of +/-10Hz on the subcarrier, so it's out of spec by about 3000 times the tolerance. Some TVs will accept this, but many will not, and you can't really blame them for this.

 

What do you mean by "accept this"? I'm using a Sony KX-14CP1 display.

I did hear about this recently regarding PlayStation 2 modchips and the PS1 side of things actually. Thankfully my debug machine is NTSC-U.

 

By "accept this" I think he meant that some TVs will accept the 3.54MHz PAL signal.
Does your 5552 play NTSC games in B/W?

 

He means NTSC with a 3.546 Mhz signal (when using a PAL console, but with video encoder set to NTSC) when its supposed to be 3.57953Mhz.

Its an out of spec signal and technically no TV needs to display it correctly. If it does, its only because the TV is being forgiving.

 

No, because I use RGB.

Okay, to put in layman terms, if the signal frequency is incorrect what does that mean to me as an end user when playing NTSC titles?

 

They will run 1% slow (both frame and line rates) and may not display color in composite mode depending on your TV. The only people I've ever known to notice the speed error are some very experienced 2D fighter players.

 

Ah right I see. Thanks for the clarification.