RGB Mod in interface unit

shugs81 · 08/08/2016, 09:19 PM

Hi peeps....

It is me again... Trying not to cause havoc tonight!! Lol

Just a quick question... I haven't received any of my hardware yet and I understand I need to rgb the interface unit... But can I ask where I put it???

I've had a search on here but I can't find anywhere that shows where in the schematics it would go...

As I say I haven't got my unit yet so haven't had a look at everything properly... Just wondered as I can't see any on here... Unless I'm rubbish at searching.... Which is possible!!

mickcris · 08/09/2016, 01:28 AM

Here is a tutorial on french. Probably don't want use their pinout though
http://www.obsolete-tears.com/forum/viewtopic.php?f=8&t=7231

hnns · 08/09/2016, 08:20 AM

Are you sure you want to RGB mod the IFU? Why not RGB mod the PCE instead. IMO this is the more versatile solution.

shugs81 · 08/09/2016, 09:04 AM

it is but seems a chew on for the audio side of things... plus it'll look neater when its done...

Cheers for the link mickcris will get my google translate on!!

CatPix · 08/14/2016, 01:58 PM

Quote from: mickcris on 08/09/2016, 01:28 AMHere is a tutorial on french. Probably don't want use their pinout though
http://www.obsolete-tears.com/forum/viewtopic.php?f=8&t=7231

The pinout used here is from the French imported of PC-Engine in the 90's.
If I can suggest something else, for a ready-made cable, would be to use a Neo Geo CD cable; just isntall a female DIN socket on the IFU, and connect the video on it; and you pick up stereo sound from the original RCA jacks. Of course if you're thinking about makign your own RGB cable for RGB monitors then anything goes.

shugs81 · 08/14/2016, 02:37 PM

That would be the plan...

Is the pinout different from the Japanese unit? I'm assuming they're the same as I read that they were imported and modified before being sold...

mickcris · 08/14/2016, 05:36 PM

if you want to use a readily made pc engine scart cable (like from retro gaming cables or the ones i make) use this pinout
https://imgur.com/9zjm5Ku

CatPix · 08/14/2016, 06:12 PM

Quote from: shugs81 on 08/14/2016, 02:37 PMThat would be the plan...

Is the pinout different from the Japanese unit? I'm assuming they're the same as I read that they were imported and modified before being sold...

They are different, (if you're talking about the French PC-Engine) because for correct SCART cabling, you need 8 pins ( RGB, Sync, Left channel, Right Channel, Ground, 5V or 12V) and the original DIN on the PC-Engine have 5.

And for SCART TVs, most TV switch in RGB mode only if a 3V signal is applied to a pin, so unless you're using a RGB monitor, or have a TV with selectable RGb display, you'll need to add this voltage, and here, a 5 pins DIN cable isn't enough for this, 7 pins is the bare minimum, if you use the shielding to provide ground; but if you replace the DIN socket, you can go right for a 8 pins one...
Of course, considering that you wanna keep stereo; if you go for mono, you can drop to 7 pins without shielding use or even 6 pins... Which is what you have on the Neo Geo, Master System and Megadrive.

shugs81 · 08/14/2016, 07:03 PM

I was planning on using the 8 pin mini din to mini din..... I'll be hooking this straight up to a framemeister so I'll be making a custom cable... I may look to making a scart in the future for other use but not just yet...

When I said pin out I meant are the points on the boards the same in a Japanese console as the French one?

When my interface unit turns up (hopefully tomorrow!!) Will I be expecting the same as in the pictures or something completely different??

Sorry for the confusion!!!

mickcris · 08/14/2016, 07:18 PM

The inside is the same. It's a standard Japanese ifu in those pictures

shugs81 · 08/14/2016, 07:25 PM

Cool... Just wanted to be sure I didn't screw it up!!

Ta peeps!

shugs81 · 10/13/2016, 12:18 PM

so... trying to fit this RGB mod from Mickcris....

audio jacks still work too!!

I get perfect audio to the TV / framemeister but have zero video... i used this link to copy from - https://translate.google.co.uk/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.obsolete-tears.com%2Fforum%2Fviewtopic.php%3Ff%3D8%26t%3D7231&edit-text=&act=url

translated from french...

I seem to be missing something as I can't work out what the difference is... other than the 5v went to the amp rather than direct to the cable...

the jack is wired as so...

this was so i could make a direct wire to wire to connect it to the framemeister... but as i discovered i don't have qa second framemeister in my workshop... and the other one is about 10 miles away it's a pain to go backwards and forwards to test... i decided that as i was going to cut a scart lead so that i had enough wires i might as well make a scart lead first...

what am i missing? does there need to be a direct 5v to the scart too??

Thanks!

mickcris · 10/13/2016, 01:36 PM

Where did you pull sync from? Iirc that tutorial has you use csync. You can try to switch it to composite video. As long make sure you wired the jack correctly. The solder side will be the mirror opposite of that pinout you posted

shugs81 · 10/13/2016, 01:46 PM

it turns out the c-sync connection in the cable had come off!!! sorted now!!! it looks awesome! cheers bud!!

tomiii · 10/26/2016, 01:30 PM

Hello Guys,

dont wont to make a new post, maybe one can help me:
I am from Europe and make the following Interface RBG Mod with THS7314 with 9pin din socket and a mega drive 2 rgb cable (the cable just have resistors in it):
http://8bitplus.co.uk/projects/nec-pc-engine-interface-unit-rgb-mod/

As csync i grab composite from the port, everything else is like the MOD from 8bitplus.(The resistors after the amp are on the scart cable ).
When i start the TV i dont have any picture, sound is ok.
When i go direct for r,g and b to the socket (skip the ths7314) then i got a picture !
So the failure must be in the amp circuit, but i make everything like the page.
I took 2 other 7314 chips but with no effects.
Have everyone a idea? I can skip the amp but i wonder why isnt work. (maybe all chips are bad , they come all from china for a very little price)?

gojira1954 · 10/26/2016, 03:50 PM

check you have the 5v at the amp for starters

mickcris · 10/26/2016, 04:34 PM

you most likely wired the circuit incorrectly or you got a bunch of bad ics. i had ordered some 7314s from ebay years ago and about half were bad so i only buy from reputable stores now.

tomiii · 10/26/2016, 04:44 PM

Yes i checked the 5 Volt on the amp.
Hm i payd 3$ for 10 Chips from China. I will test some others this week (dont have an Adapter, it takes some time to switch