PC-Engine via VGA Monitor?

[pforson]

Hi Guys,

This is my first post so go easy on me. I'm from the UK and am a regular forum user on Retrogamer. I've been getting into the PC-Engine lately (via emulation) and so decided to join up here.

I had a search but couldn't find an answer to my question so here goes:

Q. I'm thinking of buying a white PC-Engine and modding it for RGB output (I assume this is RGB component and not composite?). However, I don't currently own a TV and was thinking as to whether I could use something like this:



to connect it to my Monitor? - Will this work? Would Resolution be a problem and would I need to buy some kind of upscaler? - My monitors minimum resolution is 640x480. How about refresh rate? Any ideas or suggestions?

Much love,
Pete

[CMcK]

If you get the console modded for RGB out it will likely be with a scart connection. You would then need a suitable upscaler such as the XRGB2 plus. That will give you a VGA output which your monitor will accept. If your monitor is LCD based it will likely have a native resolution higher than 640x480 so the image will have to be scaled again. And that will degrade the image quality further.
You would be far better off picking up a good second hand CRT TV (Loewe, Philips, Toshiba etc) for use with retro systems.

[pforson]

Thanks for the reply CMcK 

The XRGB2 plus looks like it would do exactly what I require, but its £140! golly gosh.  I was hoping for something a little more affordable...

If you get the console modded for RGB out it will likely be with a scart connection.

Hmmm, I was looking at this which seems to have either component or composite out, am I wrong?



My monitors native resolution is indeed 1280x1024 but it actually looks pretty good at 640x480 @ 75Hz. I understand that using an old CRT TV would be preferable but unfortunately I don't have the physical space to add another screen into my retrogaming setup - such is life.

Ta,
Pete

[CMcK]

I cannot see that picture of the mod unfortunately.

[pforson]

I cannot see that picture of the mod unfortunately.

How about now?

[CMcK]

I'm guessing that mod is composite with left and right audio out. The PC Engine only had RF out so as poor as it sounds that mod would be an improvement. An RGB mod could yield component output but at roughly 240i I don't know if your monitor would accept that.

[SignOfZeta]

I can't believe someone more knowledgeable hasn't spoken up on this topic.

I'm no RGB expert, but here is your basic situation. The PC Engine, all of them, either has or can be hacked into having RF or composite. There are ways of hacking s-video, or component, but they require special chips and such. RGB can be pulled off the bus or right from the board, but more or less requires an amplifier because the signal strength is low.

So lets say you have a PCE modified to have an amplified RGB output...its still not going to work with most monitors. You need something that will support 240p, and unless you have an industrial RGB monitor (like in an arcade machine) an old TV made for UK/EU/JP, or a CRT that is at least 15 years old (like mid-90s NEC Multisyncs) you aren't going to be able to sync on an image that low res. If your monitor is an LCD it almost certainly isn't going to work.

Your can get an XRGB and upscan the signal into something that a modern day display can use, but after the purchase of that (£140, believe it or not, it actually a good price for one) and the RGB mod...well, I'd look again to make sure you don't have the space for a TV.

Then of course there are other solutions like LCD monitors with composite in, TV tuner cards, etc, but they all look like ass.

You best bet is a really small thrift store NTSC TV. It would cost you 20 quid and the image would still be pretty decent.

[pforson]

Thanks SignOfZeta, very useful summary.

It seems I should be able to achieve this but at a huge cost. I found this website very useful:

http://retrogaming.hazard-city.de/

Basically I need a modded PC-Engine (which I'd buy anyway) and the XRGB-3 (because its b0 mode upscales to 1280x1024 from 240p and gives great results - this is my monitors native resolution).

The only hassle seems to be to find the XRGB-3 at a sensible price (in fact, I can't find it for sale at all!!! grrrr). Anyone got one? Anyone know of a supplier?

Ta,
Pete

[Necromancer]

As an alternative to the XRGB-3, you could look for an iScan VP-50 or a VP-20 (or 30) with the de-interlacing upgrade card.  I've never used either of these products (CRT for the win!), but I've heard they're the best; unfortunately they're also the most expensive, making the XRGBs look positively cheap by comparison.

[Tom]

Just wanted to chime and mention a few things. There's no 240i mode. It's 240p and that's not the problem. The problem is that the horizontal scanrate of the PCE, Amiga, MD, NES, SMS, and most arcades is ~15.7khz. VGA is ~31khz. *Some* LCD monitors are list as going as low as 24khz, but still doesn't help you.

 The options you have:

 1) buy an old monitor capable of receiving 15.7khz horizontal scan rate (which is CGA and one mode of EGA btw. The scan rate, nothing to do with the colors).

 2) buy some PAL TV with rgb support and NTSC 60hz refresh compatibility mode

 3) hack your existing NTSC set and bypass the composite to RGB decoder and such (least likely option, requires custom home made circuitry)

 4) by one of those overpriced RGB frame digitizers that upscale the image back out to 31khz and greater scan rates. This option sucks because you loose the "scanline" effect. The gap between scanlines that you'd normally see with the right RGB monitor or TV set

 5) DIY line digitizer and upscale with a 1 scanline delay. (Some components can be had for cheap. Jameco sells 24bit RGB out DAC (has 3x8bit DACs) 60mhz for $5. SRAM can be had for $4 for 10-15ns 32kx8bit dip (way overkill in size though for this project). 8bit 60mhz ADCs for $5 each (you need three of them). Some other little odds and ends like a clock source and 15pin vga connectors, etc). Then some discrete glue logic for monitoring sync input, generating sync output, and some resettable counters to store/fetch the digitize pixels.) Can be made from off the shelf parts and no MCU "programmer" needed. Just good old off the shelf parts and painstaking soldering of a nest of wires (bread boards might not be good for this because of the high frequency).

 6) Capture device for your PC and just run composite to it (or svideo if you've made that mod for the system). 

 Sorry, not very good options - I know. I personally am going with option #5 and will make my plans available once it's up and running (I'm doing other hardware that's both related to generating VGA video output via discrete logic and analog digitization for DIY digital scope.)