Posts by nuttie

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Don't Panic. Please wash hands.

    Hi All,

    I'm having limited success getting my new Indivision AGA Mk3 to work at 1080p on an HDMI tv, and I wondered if anyone else was having more luck? Apologies in advance for the absolute wall of text...


    I've tried it with a couple of different Sony HDTVs we have in the house, both seem stable at 1280x1024p60 but not at 1920x1090p60 or 1920x1090p50. I don't think it's the Amiga 1200 as it's stable at the lower resolution but I guess it could be, if increasing the Mk3 output resolution makes the A1200 do more work somehow and get hot/draw more current? I did wonder if it might be the psu making the Mk3 unstable if it is drawing more current when working at higher resolutions but it could just be my timings are out, so I thought I'd ask on the forum and see if anyone else was trying the same things as me.


    I used the latest 1.3 tool and firmware from the iComp website to produce the results listed below:


    The Mk3 doesn't seem to read/calculate the EDID info 100% correctly, and I guess it could be the TVs giving out the wrong information. When the Mk3 checks the EDID info it adds only 3 modes to the list, but I think the TVs are capable of a lot more because I've seen them do it when connected to PCs, Raspberry Pis and game consoles. It looks (at least to my not-expert eyes) like the Mk3 is getting most of the information correct for the resolutions it lists, but not the back porch setting, and then because of that, the frequencies are wrong which results in no picture. Below is what the Indivision tool returns, I've highlighted the fields I think are incorrect.


    EDID 1920x1080@66 (Does not work, causes "unsupported signal, check your device output")

    Pixel Clock: 148500000Horizontal Timing: Vertical Timing:
    Visible: 1920 Visible: 1080

    F. Porch: 88 F. Porch: 5

    Sync Len: 44 Sync Len: 5
    B. Porch: 0? B. Porch: 0?

    Polarity: Pos Polarity: Pos

    Freq KHz: 72.3684? Freq Hz: 66.3930?


    EDID 1280x720@65 (Does not work, causes "unsupported signal, check your device output")

    Pixel Clock: 74250000

    Horizontal Timing: Vertical Timing:

    Visible: 1280 Visible: 720

    F. Porch: 110 F. Porch: 5

    Sync Len: 40 Sync Len: 5

    B. Porch: 114? B. Porch: 0?

    Polarity: Pos Polarity: Pos

    Freq KHz: 48.0893? Freq Hz: 65.8758?


    EDID 1280x1024@60 (Works fine.)

    Pixel Clock: 108000000

    Horizontal Timing: Vertical Timing:

    Visible: 1280 Visible: 1024

    F. Porch: 48 F. Porch: 1

    Sync Len: 112 Sync Len: 3

    B. Porch: 248             B. Porch: 38

    Polarity: Pos Polarity: Pos

    Freq KHz: 63.9810 Freq Hz: 60.0197


    Further to this, I tried changing the settings for 1080p to the following, which I think should work and which do produce a picture, just not a stable one...


    TEST 1920x1080@60 (Works but causes screen to blink out every 5-10 seconds for ~1 second)

    Pixel Clock: 148500000

    Horizontal Timing: Vertical Timing:
    Visible: 1920 Visible: 1080

    F. Porch: 88 F. Porch: 5

    Sync Len: 44 Sync Len: 5
    B. Porch: 148             B. Porch: 35

    Polarity: Pos Polarity: Pos

    Freq KHz: 67.5000 Freq Hz: 60.0000


    TEST 1920x1080@50 (Works but causes screen to blink out every 5-10 seconds for ~1 second)

    Pixel Clock: 148500000

    Horizontal Timing: Vertical Timing:
    Visible: 1920 Visible: 1080

    F. Porch: 528 F. Porch: 5

    Sync Len: 44 Sync Len: 5
    B. Porch: 148             B. Porch: 35

    Polarity: Pos Polarity: Pos

    Freq KHz: 67.5000 Freq Hz: 60.0000


    I believe both of these settings should should work fine on the TVs because they are the exact same settings I can see my PC's graphics card sending to the same TVs when I set it to those modes. I just can't figure out why it's not stable when I get the Mk3 to do it. If anyone has any ideas what I'm doing wrong, please let me know.


    The 1024p mode is totally rock solid stable and works great but in order to get the pixels 1-1 I have to set the Mk3 to scale the screen to 640x512 which means I lose the edges of the picture on any games (Battle Squadron, Rainbow Islands etc.) where the Amiga's screen is not left aligned. If I could get either 1080p mode to be stable, I can scale the screen 1-1 with some extra pixels in the margin, to help fix that. Also, I am wondering if using the 50Hz modes on the TVs would help with v-sync and screen tearing? The picture seems tonnes better when the TVs are in game mode, and Mk3 has a clean ratio between input and output resolutions. I've also tried to set up some 576p modes but no luck so far, I get a black screen but no "unsupported signal, check your device output" error message from the TVs, so something is different again with those modes - my reason for trying with those is the lower pixel clock and integer scale for games.

    Again, apologies for the wall of text, I just wanted to write down as much as I could in case it was useful to anyone trying to figure out the same things.