G4 iBook drive LG Ultrafine 4k?

Discussion in 'PowerPC Macs' started by filmbuff, Dec 4, 2018.

  1. filmbuff macrumors 6502a

    filmbuff

    Joined:
    Jan 5, 2011
    #1
    Okay obviously it won't drive it at 4k resolution. This is more of a thought experiment or something that would be fun to try. What would I need to do to hook up my iBook G4 to the LG Ultrafine 4k with USB-C only? Is there a series of adapters that would work or is it totally impossible? The iBook has a mini VGA port.

    mini-VGA > VGA
    VGA > USB-C ??
     
  2. mode11 macrumors regular

    mode11

    Joined:
    Jul 14, 2015
    Location:
    London
    #2
    Almost certainly impossible, but I'll have a go:

    First, you need something to digitise the analogue signal, e.g. a VGA to HDMI convertor. These cost £10 or so e.g. https://www.amazon.co.uk/Converter-...01LPU42SO/ref=cm_cr_arp_d_product_top?ie=UTF8.

    USB-C-connected monitors are likely using the DisplayPort protocol, carried over some of the USB plug's pins. So the next conversion would be from HDMI to DisplayPort. These adapters can be had for £25: https://www.amazon.co.uk/UGREEN-Dis...00WM6MPGC/ref=cm_cr_arp_d_product_top?ie=UTF8.

    From there you would need to connect DP to USB-C. One method would be to adapt DisplayPort to a female Mini DisplayPort (£7.50): https://www.amazon.co.uk/StarTech-c...003N3DTKY/ref=cm_cr_arp_d_product_top?ie=UTF8.

    Finally, you would use a mDP to USB-C lead (£15) to connect to your monitor: https://www.amazon.co.uk/TNP-USB-C-...072JX6HP2/ref=cm_cr_arp_d_product_top?ie=UTF8.

    The problem is the last part. USB-C has a bunch of 'alternate modes', whereby it allows other protocols such as DisplayPort or HDMI to be delivered over some of its pins. The issue is likely that this needs to be negotiated, which a simple adapter won't be able to do. I'm sure it's technically possible, but to my knowledge, no products actually exist to do it. Usually, you're going from USB-C on a computer to DP, HDMI, Thunderbolt etc., not the other way round. What you are postulating is akin to putting the genie back in the bottle.

    The only practical solution would be to use another computer attached to a video capture card (or perhaps Screen Sharing over Ethernet), then output from USB-C on that to the monitor directly.
     
  3. Amethyst1, Dec 5, 2018
    Last edited: Dec 5, 2018

    Amethyst1 macrumors 6502

    Amethyst1

    Joined:
    Oct 28, 2015
    #3
    There's http://www.sunixusa.com/product/upd2018/ which takes a DisplayPort input and outputs it via USB-C Alternate Mode. I think I've come across a report of the UltraFine 4K working with this gadget – edit: here –, so it's theoretically "just" a matter of getting a DisplayPort signal out of the iBook and supplying power to the card. :)

    Great question, by the way. If I had an UltraFine I'd try this :D
     
  4. Eightbitgamer757 macrumors member

    Eightbitgamer757

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    Feb 8, 2018
    Location:
    Idaho
    #4
    The Ibook g4 only supports up to its native resolution(normally 1024X768) so nothing higher than that for a resolution
     
  5. mode11, Dec 5, 2018
    Last edited: Dec 6, 2018

    mode11 macrumors regular

    mode11

    Joined:
    Jul 14, 2015
    Location:
    London
    #5
    You could probably get a VGA to HDMI convertor that could just scale any input resolution to 1080p, which the UltraFine would likely be fine with (a simple 2x scale).

    The second device I mentioned would then convert from HDMI to DP.

    The Sunix card is the sort of thing that’s needed. Perhaps it could just be supplied with 5V, with the DP input just passing through video over the USB-C connector, with no USB traffic. Would save having to install it into a desktop computer. Perhaps some kind of 1x PCIe extension, normally used in mining rigs?

    Edit: it can -
     
  6. AphoticD macrumors 68000

    AphoticD

    Joined:
    Feb 17, 2017
    Location:
    Australia
    #6
    If you really want to get the most out of the TV’s resolution with a PowerPC Mac, the last generation PowerBook G4 DLSD 15” or 17”, or the 1.67GHz SLSD 17” models are capable of driving 2560x1600 on an external display. I have confirmed this with a 27” WQHD (2560x1440) display on a DLSD 15”.

    The Dual-link DVI output would still need to be adapted to USB-C, but there would be no analog to digital conversion and the output will sure look a lot nicer than the iBook’s mirrored 1024x768 resolution.
     
  7. Amethyst1 macrumors 6502

    Amethyst1

    Joined:
    Oct 28, 2015
    #7
    I have confirmed that an SLSD will do 3840x2160 at 30 Hz without further ado but experienced framebuffer corruption once screen elements moved past a certain point.

    You could use an Atlona DP-400 to convert DL-DVI to DisplayPort and feed that into the Sunix card to adapt to USB-C.

    With regards to iBooks and screen mirroring, doesn't a NVRAM edit enable driving an external screen at higher resolutions than the internal LCD? You'd still be stuck with a VGA output, though.
     
  8. mode11 macrumors regular

    mode11

    Joined:
    Jul 14, 2015
    Location:
    London
    #8

    Screen spanning hack: http://www.rutemoeller.com/mp/ibook/ibook_e.html

    If this can give 1920x1080, the cheap VGA to HDMI I mentioned earlier would be fine.
     

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7 December 4, 2018