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  • Lona Theartlavtheartlav@anarres.family
    Apr 7, 2026, 8:56 PM

    Next step - i want to get the dreamcast to connect to the internet, or what's left of it.
    Connecting the modems directly did nothing. While there are ways around that when connecting two PCs, the console browser does not really let you run custom AT commands.
    So i had to cobble together a line voltage injector, confirming in the process that i have a PAL version of the sega modem which needs at least 18V.
    With that it did manage to connect, but was too glitchy to establish an actual link.
    Now that the concept is proven, it's time to clean it up a bit.
    And maybe add a line speaker.

    A desk full of wiring, Dreamcast, power supply, soldering iron, and similar mess. There is a monitor that shows the dreamcast's video output and a terminal with the receiving modem's raw output.
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  • Lona Theartlavtheartlav@anarres.family
    Apr 8, 2026, 12:19 AM

    And some rummaging later here we have a USB-C to phone line voltage converter.

    No more glitching.
    Still need to find a speaker, however.
    I forgot that phone lines require high impedance speakers, and these are kind of unobtanium these days.

    Well, more unobtanium that the rest of this stuff.
    I thought CD-Rs, phone wires and jacks, stuff like that, would be your regular electronics store filler.
    But nope, not any more!
    I found CD-Rs in a random book store, and so far it was the only store i found them in.
    Phone wires and sockets are still findable, but they are definitely not filler any more.

    I'm getting old... Familiar tech is getting extinct...

    Two phone plugs and a USB-C 20V trigger board glued together and wired to each other.
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  • Lona Theartlavtheartlav@anarres.family
    Apr 8, 2026, 12:37 AM

    At some point i got the sound working (RCA cables are also rare these days!), and just started playing a game.
    Sonic Adventure 2.
    Used to be my favourite at some point.
    By Dreamcast days i was already past my sonic speedrunning days, but still i used to have almost everything unlocked in that game.
    I used to be good at it.

    ...I was trash at it.
    The controls feel weird, i couldn't follow the track or do any tricks.
    Gotta be rusty, right?
    Well, i was a little bit too rusty, which got me suspicious.
    And then it hit me.

    Latency.

    This is a highly dynamic game where you often got a frame or two to react to get things right.
    And my chain of two adapters and a capture card were adding some non-trivial latency.
    Not enough to notice immediately, but enough to throw everything off.

    I tried to skip the capture card at least and plug directly into the monitor, and it made a huge difference.
    I was still kinda bad at it, but it felt a lot more natural and i could actually do some things.
    The muscle memory was waking up and felt in sync.

    Going back to the usual setup, the latency was now blatantly obvious.
    It's only several frames worth, something i always discarded as irrelevant.
    Well, now i know why it matters.

    A screenshot from Sonic Adventure 2, with a debug terminal on the other half of the screen.
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  • Lona Theartlavtheartlav@anarres.family
    Apr 8, 2026, 6:10 PM

    So i bought a 25 pack of CDRs, expecting a bunch of them to fail again and to end up with a nice empty spindle to put them back on.

    ...7 discs later, i'm yet to have a single failure.
    Sigh. Guess i'll have to house them together with the blanks now.

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  • Lona Theartlavtheartlav@anarres.family
    Apr 10, 2026, 3:50 PM

    Going through the SH-4 instruction set.

    DIV0U ;prepare for unsigned division
    DIV0S Rm,Rn ;prepare for signed division Rn÷Rm
    DIV1 Rm,Rn ;generate 1 bit of the quotient Rn÷Rm

    head scratch
    Guess i don't get to have a "divide these two integers, please" instruction.

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  • Brialastatic@aus.social
    Apr 8, 2026, 12:27 AM

    @theartlav I wish we could corral all the people who want old tech to still be around and get our own manufacturing systems.

    Or something like that.

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  • Sym (public node) :3hearts:SymTrkl@anarres.family
    Apr 8, 2026, 12:28 AM

    @theartlav Oh that's cool, you
    I'm sorry a what voltage converter!? :neobot_0_0:

    Reading upthread is making this seem much less scary, but damn girl, the thought of on-hook or ringing voltages going anywhere near a USB-C plug had me shook. :neobot_laugh_tears:

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  • Lona Theartlavtheartlav@anarres.family
    Apr 8, 2026, 12:42 AM

    @SymTrkl Good thing i only need to inject the well-within-USB-PD-spec 20V into the phone line for the modems to stop throwing a hissy fit and start beeping at each other.

    Tho it honestly wouldn't be past me to make something USB-C powered that does some 100V shenanigans.

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