Getting the C-Sync from PS1 w/o LM1881

[SAM]

It is quite simple to get the c-sync from the composite video line using a LM1881 chips.

But this might not be the best solution, since the LM1881 does got some drawback:

(1) It takes some effort to found the chip.
(2) It needs +5V power supply.
(3) It would cause interferance with some vedio chips.
(4) The C-Sync singal is downgraded
when encoded into the Composite Video singal.

There is an alternative method of getting the C-Sync from PS1.

I tried this yesterday.
http://www.gamesx.com/wiki/doku.php?id= ... ion_1_sync
In short, getting the H-Sync & V-Sync from directly from the CXD8561 chip (Pin 155 & 156).

Benefit of this method over the LM1881 chip
(1) You only need a 820 Ohm resister & a diode, which is readily avaliable in any radio electronic parts store.
(2) You could have h-sync and v-sync seperately, and this is a required input format for some RGB monitor.
(3) The sync singal is in it's most pure form, it haven't been compressed into anything yet, should resulting in a sharper image.

[iatneH]

You're going nuts on PS1 hacks

[SAM]

You're going nuts on PS1 hacks

Yes, you are right.

I had spent too much time fooling around with the PS1 PCB while I should be playing video game instead. That's why I still cann't get pass Stage 3 of Under Defeat...

I got lost in the process and had forgotten why I want to hacks a PS1 in the first place...

[antron]

downside of this is replacing your PS1 now requires getting out your soldiring iron.
i like cable only solutions.

[SAM]

downside of this is replacing your PS1 now requires getting out your soldiring iron.
i like cable only solutions.

Sorry, the PS1 RGB cable can't solve the problem. Since PS1 only got C-Video at it A/V pinout, you don't got C-Sync at the RGB sync pin also, you got c-video instead.

If you use the traditional LM1881 circult in the RGB cable plug, you still need to solder the wire, cap, resister to the pin of the LM1881 chip.

Either ways, you have to do some soldering. But my suggestion cost less and get a better result. If your PS1 happen to be those with seperate C-Video jack, you could still retain a C-video output after the mod.

[antron]

If you use the traditional LM1881 circult in the RGB cable plug, you still need to solder the wire, cap, resister to the pin of the LM1881 chip.

you do all that to the cable, not the console.
when your cd drive goes out, you just replace the console.

[SAM]

If you use the traditional LM1881 circult in the RGB cable plug, you still need to solder the wire, cap, resister to the pin of the LM1881 chip.

you do all that to the cable, not the console.
when your cd drive goes out, you just replace the console.

Yes having the sync seperate circult within the cable is an advange , but you have missed the point.

If your CD drive goes out, you should replace the drive not the console. (For instance, I got some spare PS1 CD drives and willing to sell for a small sum of money.)

The good thing of having the sync seperating circult within the cable is you could also use the cable on a PS2 console.

[matt]

This is silly. LM1881 chips are easy to get from almost any electronics supplier and cost only a few dollars each. Wiring up a quick sync separator circuit is easy and much less work than this mod.

And the sharpness of the picture is governed by the RGB signals, not the sync. The picture you get will be the same either way.