The item can now be bought on eBay (only one left when I write this, but the seller seems to keep adding new batches).

I did some basic tests with mine and I'm really impressed with the overall result.
My main purpose is to get the best possible result on a LCD for old games without any deformation and by filling the screen as much as possible. Most of the CGA and VGA games used a 320x200 resolution and 640x200 for EGA which correspond to a 16:10 ratio... except that most CRTs of the time were 4:3. Graphics were designed to fit these monitors so they were based on non-square pixels with a ratio of 5:6. What was possible with CRTs but isn't with LCDs whose square pixels cannot be vertically stretched. This is best explained in this article.

The default "Standard PC" profile of the RBGtoHDMI uses a 2:5 pixel ratio which is very close to 5:6. For an even better result, and if we are to keep the very sharp integer scaling, we can use a 5:6 x 320x200 = 1600x1200 monitor. That is perfect for CGA (and old VGA) games as this has already been concluded in this topic.
IanB kindly provided me with such special profile (attached) that displays a razor-sharp non-deformed and fullscreen picture using integer scaling. Beware that it won't work well with other source/destination resolutions than the indicated ones.

As seen on Deluxe Paint II in CGA (320x200 4-colors mode), the circles are perfectly round:

Going the same with 640x200 EGA is not as easy as it would require a 5:(6 x2) x 640x200 = 3200x2400 LCD. This is called QUXGA but is rare and expensive.
So if I am to stick with 1600x1200, I have to resort to the softer interpolated setting with (5 /2):6 x 640x200 = 1600x1200. I found this to be the best compromise, even though the image is not as sharp as with integer scaling: it is still very good. Also, by keeping the same LCD I can easily switch with IanB's profile (the scaling must be changed from interpolated to integer in addition to the profile switch which is a bit of a bummer).
I've attached this custom CGA+EGA profile that overrides the default "Standard PC". It works fine with 320x200, 640x200 and 640x350 with a non-deformed fullscreen image on a 1600x1200 monitor with scaling set to Interpolated 4:3 (soft).

EGA lo-res:

EGA hi-res:

Monkey Island with scanlines:

I’d be interested in a board if you have any left ? I run the Amstrad IBM PC compatibles group, would like to try out on a few systems, looks awesome from what I’ve seen here 😀

IanB wrote on 2019-04-02, 00:37:

The PCB design and code are on github This is my fork: https://github.com/IanSB/RGBtoHDMI/tree/dev This is hoglet's original (my […]
Show full quote

keropi wrote:

this is all very interesting, how can I build this to test?

The PCB design and code are on github
This is my fork:
https://github.com/IanSB/RGBtoHDMI/tree/dev
This is hoglet's original (my changes are usually merged back in)
https://github.com/hoglet67/RGBtoHDMI/tree/dev
(All the current work is in the dev branch at the moment)

keropi wrote:

if there is any way to contribute to testing do tell!

Do you want to build one yourself? I still have a few prototype pcbs
Construction details here:
https://github.com/hoglet67/RGBtoHDMI/wiki/Bill-of-Materials

Note the current PCB was designed for the BBC micro which has composite sync and 3 bits RGB so had to be reworked slightly to connect the separate H and V sync and 6 bits RGB:
extrabits.jpg
There will be a new pcb design sometime fairly soon which will be more universal.

keropi wrote:

Is it possible to add a scanlines effect as well?

Yes although it can interact with the integer scaling depending on monitor size and source resolution. In the case of CGA/EGA 640x200 on a 1080p monitor below, there are 2 LCD pixels of video and 3 pixels of black for each line pair: (Make sure to zoom to 100%)
scanlines.png
If there are any unevenness issues with integer scaling and scanlines you can always switch on interpolation.

One other feature I forgot to mention is that it supports reprogramming of the output palette by displaying specific patterns of pixels which are unlikely to occur with normal operation as they look like random noise. (Although this feature can be disabled in case something triggers it accidentally)

This was primarily for use on the BBC micro to do things like change this:
RawRGB.png
Into this:
palette.png
But a DOS command line tool could be written to change the palettes on old CGA games to something less garish.

Richard Poll wrote on 2021-04-20, 06:00:

I’d be interested in a board if you have any left ? I run the Amstrad IBM PC compatibles group, would like to try out on a few systems, looks awesome from what I’ve seen here 😀

If you go to the seller's page you'll find his current listing for this device.

weedeewee wrote on 2021-04-23, 19:17:

Richard Poll wrote on 2021-04-20, 06:00:

I’d be interested in a board if you have any left ? I run the Amstrad IBM PC compatibles group, would like to try out on a few systems, looks awesome from what I’ve seen here 😀

If you go to the seller's page you'll find his current listing for this device.

Except that he has no current listings that I can find 😀

debs3759 wrote on 2021-04-23, 20:01:

weedeewee wrote on 2021-04-23, 19:17:

Richard Poll wrote on 2021-04-20, 06:00:

I’d be interested in a board if you have any left ? I run the Amstrad IBM PC compatibles group, would like to try out on a few systems, looks awesome from what I’ve seen here 😀

If you go to the seller's page you'll find his current listing for this device.

Except that he has no current listings that I can find 😀

then I guess this must be a link from an alternate universe
https://www.ebay.fr/itm/254912910631?hash=ite … aQAAOSw4zdgBCSi

ps. don't click it if you're not from the same universe. Dimensional swapping can be a real cause of mental distress and you will encounter unexplainable memory lapses.

edit : direct link to ebay sellers page, since the link in the first post no longer gives any meaningful results https://www.ebay.fr/usr/marminsky

When I click on "Afficher les autres objets", it shows nothing. Even from that link. Maybe because it knows I'm in the UK so no longer in the EU 🙁

debs3759 wrote on 2021-04-23, 20:59:

When I click on "Afficher les autres objets", it shows nothing. Even from that link. Maybe because it knows I'm in the UK so no longer in the EU 🙁

I changed the .fr to .co.uk and it still works for me... though, I'm still in the eu.
and yes, it seems only eu countries are listed under the postage & packaging

Postage to: European Union
Excludes: United Kingdom

I can see the listing from your link, it's just that trying to see all his listings shows up as blank. I might ask a friend to get one for me when I make this month's card payments next week.

debs3759 wrote on 2021-04-23, 21:51:

I can see the listing from your link, it's just that trying to see all his listings shows up as blank. I might ask a friend to get one for me when I make this month's card payments next week.

that's an annoying ebay feature, oh well.
Did you check out the forum link from the first post ?
I get the impression that this is actually developed and designed in the uk, though one guy selling it, Ianb, is currently not doing so due to illness. (I just read it on the forum)
the other option would be to BYO 😉

I have looked now (hadn't before) and will register over there over the weekend, so I can ask if anyone in the UK can supply one built and tested. Haven't used a soldering iron in 45 years (although will be learning to repair motherboards and add-in cards for PCs this summer) so not currently confident enough to try building one.

I'm thinking of putting together a couple of these for myself and I'm in the UK, so I could put some on ebay once they're ready.
It looks like there are lots of the Amiga specific ones, but not so many of the generic type ones.

Something I'd like to understand - does the latest version do VGA input? That would be perfect if it does, I just got an LCD control board, but it gives an out-of-range error when trying to display the BIOS or DOS screens.

Thermalwrong wrote on 2021-05-22, 19:29:

Something I'd like to understand - does the latest version do VGA input? That would be perfect if it does, I just got an LCD control board, but it gives an out-of-range error when trying to display the BIOS or DOS screens.

I think the topic title is wrong, in that this will never do vga, since it uses digital input, and no analog which vga is.

On another note, it seems as the creator of this board is back on track to start building and selling more of them. So probably good time to get your order in if you want one and live in the uk.

edit: it's mentioned in the first post that there 'might' be some vga with digital output, though not very common.

Has anyone done any tests with VGA, especially oddball dos resolutions, this could finally make near pixel perfect dos streaming possible?

If so on VGA what is the resolution limitations, 320x200 or 320x240 is great for dos, but 640x480 would make windows possible too?

Edit: Sorry didnt see weedeewee comment 🙁 so I presume only ega atm?

No luck with ordering any from the link. If anyone is placing an order with pcbway can you add some for me of the universal 12bit?

I'm gonna try my hand at replicating this project, following the footsteps of Adrian (from Adrian's digital basement on YT). He was sent the 6/8 bit issue 3 board with a pc TTL extender.
https://youtu.be/iGLE0J0sZOQ (15:07)

Here's his successful implementation into a Macintosh Classic II https://youtu.be/pvjsXbz1xlk

I'm kinda lost at what I should get in 2022. 12-bit is really overkill as I don't own an Atari ST or plan to or anything of the sort. I'm happy just using this for my monochrome compact Macs, but if I can intercept some VGA modes from my 486 (vga card) then, cool. Adrian just used 4 pins (H, V, Green, GND) out of his 6/8 extender, which is now marked as an older revision.

Also currently exploring hunting parts vs making them assembled in JLCPCB.

FaSMaN wrote on 2021-08-04, 08:09:

Has anyone done any tests with VGA, especially oddball dos resolutions, this could finally make near pixel perfect dos streaming possible?
If so on VGA what is the resolution limitations, 320x200 or 320x240 is great for dos, but 640x480 would make windows possible too?
Edit: Sorry didnt see weedeewee comment 🙁 so I presume only ega atm?

These are no good for VGA as they are limited to either 27 or 64 colours depending on whether You add another IC to the board or not.
I mistakenly thought I could use it for an RGB modded Atari 2600 I have. The Atari 2600 supports up to 128 colours so that was a no-go.
I'll quote the response I got from the designer of these.

"There isn't a profile for the Atari 2600 with RGB mod so you will have to create one.
Also I think the 2600 has 128 colours and the analog board can only distinguish 27 colours or 64 colours with the U7 fitted.
It may be possible to get a usable output by setting up your profile but some colours will be a shade wrong."

I`m trying to get RGB2HDMI up and running, so far my result with CGA:

could this be a wiring issue ?

Pardon me skimming through this thread: But what benefits does this have over something like a OSSC?

Price.

FioGermi wrote on 2022-04-15, 19:18:

Pardon me skimming through this thread: But what benefits does this have over something like a OSSC?

It converts from digital to digital without going through an analog stage.