upscaler screen offset

geebus · 21:18, 24 November 19

Hi all, Here's a weird one for you all!I'm looking to do some recordings using the original hardware as much as possible. I was thinking about splitting the video output etc, so I could use an amstrad monitor but that'll need to wait till I work out how i'm going to split the signal and also boost it to two outputs. In the meant time i'm just going to use an active scart lead to an upscaler which in turn goes to a hdmi recording device (Elgato HD if you're wondering) which I can then just use a pc monitor from the Elgato's output.
My issue here is; the image coming from the upscaler has the screen offset to the right, so some of the border is hidden. Not too much of an issue really seeing as it's only the border, but i'm a bit of a perfectionist. I tried my non active scart lead and it had the picture showing (with ghoasting as I was expecting), and it would momentarily move from one side of the screen to the other. This is leading me to thing that the 5v in the active line is to help with the h-sync. Is this correct and could I add a (further) resistor into the scart to move the picture at all?
I'd love to hear your thoughs or experience with this.Cheers,Alastair

geebus · 21:34, 26 November 19

Nevermind. It's the upscaller.
I just got my power supply for the GX4000 through the door and thought i'd do a test. Yep, still offset to the right.
Looks like it's a common problem with these cheapo upscalers.

Bryce · 08:32, 27 November 19

Adjusting the 5V or adding resistors won't help. The 5V is to tell the TV to switch to RGB mode. The offset has to so with the timing between the sync signal and the picture data. This is defined deep inside the Firmware of the upscaler.

Bryce.

geebus · 11:10, 27 November 19

Thanks Bryce.
Looks like theres a UART port on the device. So I might do some digging.... and breaking..

Bryce · 11:20, 27 November 19

What upscaler have you?

Bryce.

geebus · 12:04, 27 November 19

This cheap-o thing from amazon.
https://www.amazon.co.uk/gp/product/B078JJMR5J/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I might just get an OSSC. Buy cheap, buy twice eh!

Bryce · 12:41, 27 November 19

Ok, haven't hacked one of those yet. Have a sniff of the UART, it's probably running some minimal Linux distro.

Bryce.

geebus · 12:55, 27 November 19

I've never dove into anything with UART, so that will be a learning curve all on it's own.
Linux has been my main OS for many years and i've delved into it a few times, so hopefully I can find something once i've figured out how to UART into it (if it is a linux on a chip).
I'm going to give the board a good clean as there's some residue from flux on there and some of the soldering is just terrible. So I'll check that first just in case, then go for the UART if it's still the same.

Bryce · 13:00, 27 November 19

Just connect it to a computer running Putty and see what it reports when booting. Unfortunately, many systems are configured to output only on the UART, so you can see what's going on, but it may not let you manipulate any code.

Bryce.

geebus · 13:15, 27 November 19

I'll need to grab a USB to UART cable and give it a go.
I'll let you know how i get on. Cheers again Bryce.

geebus · 11:51, 02 December 19

I've done a bit of research into this device. It turns out it's pretty much an mstar lcd tv chip in it. If you use the mstar software you can control it in other ways that you're not supposed to be able to.
My UART cable should arrive today, so hopefully I'll get a chance at some point soon to use the software and fix the screen position and maybe even the aspect ratio.
I might make a new top to the case so that I can incorporate some new buttons to change between 16:9 and 4:3, a soft power on/off and anything else useful I can find in there.
A bit more info can be found on the following YouTube video

https://youtu.be/dvcoXRKdPvI

geebus · 00:27, 04 December 19

Ok, so I'm managed to UART into the device (baud rate is 115200 if anyone else needs to know).
I can't seem to change anything which is a bit sad.
If I use the mstar software, it has the ability to change the screen position but it doesn't send it to the device itself sadly. Or I don't know how to send it.
If I use PuTTY it gives me a menu but has nothing that I can see to move the screen. Looks like it's stuck the way it is.

News:

upscaler screen offset