Medusa is a device that allows connecting of old computers to modern displays | Hacker News Reader

Medusa is a device that allows connecting of old computers to modern displays

medusa-sc.org

144 pointsdoener72 comments

It is strange that there are no pictures of this device. However, with the (brilliant) name, I can easily guess what it looks like.

There have always been adapters and multi-adapters because of hand-held video recorders, various entertainment units, and even overhead displays. Even HDMI comes in Standard, Dual, Mini, Micro and a specialized Automotive connectors.

Looks like there's some more info here: https://lotharek.pl/productdetail.php?id=135

There's a video, but it's half an hour of calibrating a pick and place machine.[1]

[1] https://youtu.be/IAsJbZpvYHU

The price point is pretty step at $169.

I thought that at first. But if you need to translate between a lot of the devices this would work with, you might spend more than that on all the different adapters.

For someone with a lot of retro gear mixed in with new gear (like me), it's probably not such a bad price. Especially businesses that digitize home videos etc.

I wonder if there is surge control on the inputs. The number one reason I have to replace video adapters is the input buffer frying. Ironically that often results in a not-blue screen of death.

Welcome to small-production-run hobbyist electronics. The stuff you see at Walmart is cheap because they make 50,000 at a time.

Also, the cheap options are using off-the-shelf upscaler chips that will choke on anything other than NTSC or PAL video baseband - the kind of chips that go into TVs that have retro inputs. As far as I'm aware there is no chip on the market that you can buy that will handle arbitrary analog video modes to the fidelity that we want them, and pretty much everyone is using some amount of FPGAs to handle some part of the conversion[0]. That's like half the BOM cost on these things alone.

[0] Don't ask me how much. I imagine you probably couldn't directly sample analog video on an FPGA.

For home computers like c64 and amiga that'll be enough though. They were TV based. I didn't realise this was that expensive. Probably will go for a Chinese option then as they're only 20 bucks.

https://github.com/hoglet67/RGBtoHDMI/wiki $5-10 pi + $3 cpld + some comparators and a DAC for the analog addon https://github.com/hoglet67/RGBtoHDMI/wiki/Bill-of-Materials...

No it’s not. You are just accustomed to Chinese garbage electronics.

What would be the best price, and how would you get it there?

That's not unusually expensive for this type of hardware. My RetroTINK 2X was around 130

If there are no alternatives that exist, it seems very reasonable. You'll spend much more time/$ on hacking it together yourself with an FPGA.

> It is strange that there are no pictures of this device.

You'd be petrified to see it.

Man, it doesn't even cover CGA displays (200x160,16 color)!

CGA 16 colour was only 160×100 (it was 80×100* text mode pretending to be graphics [1]). Much more commonly used was 320×200 4 colour.

* Font height changed to 2 pixels, so 100 lines of "text" instead of 25 (640×200 actual pixels).

[1] https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/wp/c/Color_...

That was the first thing I looked for as well. I have a service monitor (combination tracking generator and spectrum analyzer) witch CGA output. There's a fair amount of old engineering equipment with CGA out. They typically have green CRT built in, but if you do hook up an external monitor you get a rather nice color display.

Not a total loss, CGA was also also popular in cabinet arcade games. You can get converter boards. All the ones I've seen had 5-pin headers and you have to build your own cable.

The main thing is that I can't find the license. I have to assume it's a proprietary solution.

It seems like an attempt to snip the OSSC Pro, an open source hardware (OSHW) solution which is set to release soon.

I came to here request a picture also

Yeah or a link to buy it.

This is nice, but how about a way to connect modern computers to old displays? I have several really nice displays (mostly in old laptops, but also an SGI 1600SW) that it would be great to have a DVI or similar input for in one way or another.

Your laptop monitors probably use lvds/edp to interface with the motherboard. You can buy a converter to displayport for those. For your old monitors that use non-standard interfaces you should just buy a new one. Acquiring a converter will be expensive and time-consuming. You might as well just buy a new Dell ultrasharp, which is guaranteed to be much nicer.

The idea is to avoid a big chunk of e-waste from disposing of a perfectly good monitor. Of course the converter introduces electronics of its own, but it's a much smaller thing than a new Dell Ultrasharp, and hopefully much less expensive as well.

lvds to displayport converter is interesting and I should look into it. Thanks for mentioning.

I love old monitors but, like old fridges, it is probably better for the environment to scrap them than to preserve them.

Modern displays are ridiculously more power efficient.

“Modern” displays are some combination of 16:9 at best (and even that is being supplanted by even more ridiculous aspect ratios), use fake 10-bit color mode, have terrible color gamut, bad viewing angles, horribly glossy, or some other incredible limitation. There is literally no “modern” equivalent for my barely ten year old ZR24W/ZR30W. It heats up my office in ways a new UltraSharp doesn’t, but that Dell wastes its retina pixels on real estate I can’t use. I say all this as someone that actually welcomes a hi-dpi, hi-fps, low-power, etc version of the hardware I’ve got.

> fake 10-bit color mode, have terrible color gamut, bad viewing angles, horribly glossy, or some other incredible limitation.

From the ad copy of a Dell U2720Q 4K 27":

> Exceptional color: Get wide color coverage with 95% DCI-P3 – which covers approximately 25% more color space than sRGB – for true color reproduction. This monitor also offers 99% sRGB and 99% Rec 709 color coverage.

> Outstanding color depth: With and outstanding color depth of 1.07 billion colors (that’s 64 times more color depth than standard monitors), excellent peak brightness and a high contrast ratio of 1300:1, images are displayed in true-to-life color with clear details even in dark shadows or brightly lit areas. Be prepared for better color gradation and precision in more shades on this VESA DisplayHDR™ 400 monitor.

> True-to-life details: 4K UHD (3840 X 2160) resolution with a high pixel density of 163ppi gives you four times more details than Full HD.

> Accurate color, out of the box: Your monitor is factory calibrated at 99% sRGB to an accuracy of Delta-E less than 2 for accurate colors right from the start.

- Better color gamut - 178 degree viewing angle - Brighter panel - Anti-glare coated

Even if you don't get 10-bit you'll get more accurate colors because the deltaE value is lower. And since you panel is 10 years old panel uniformity will certainly be much better.

I bought 2 used 4K Dell U2718Q displays (the older model) for 250 each. The best displays I have ever used. Very worth it. I recommend you demo 1 if you can.

If you’ve got extra money, I can recommend the UP2718Q (not the U2718Q), which is used ~800€, but has a true 10-bit panel and 1000 nits peak brightness.

Copying my comment to GP:

That's a 16:9 display and you won't get the same real estate. I'm using my monitor at its native 2560x1600 at 100% scaling. 3840x2160 at either 27" or 32" (I've tried both) is unusably small at 100% and only a scant 2560x1440 at 150% scaling. The difference from 1600p to 1440p is rather stark and very hard to swallow.

> Your laptop monitors probably use lvds/edp to interface with the motherboard. You can buy a converter to displayport for those.

As a sidenote - why is a converter for eDP needed in the first place, other than to supply power for the backlight, and to adapt the connector to the usual flat cable?

If I read the Wikipedia article correctly [1], eDP is a superset of the DisplayPort standard, with added functionality to control the panel/backlight via the AUX channel and support for an on-panel framebuffer - so in theory one should be able to directly drive an eDP panel from a DisplayPort connector with a passive adapter and some way to supply power to the backlight.

[1] https://en.wikipedia.org/wiki/DisplayPort#eDP

I've spent many hours trying to get my 2012 iMac to function as secondary display for 2020+ macbook(s). It worked perfectly well with 2019- macbook(s). The iMac is perfectly functional and has capability to be used as a "Target Display". Screw the folks who advocate dropping features like this so that I can generate more waste & buy newer crap from them.

The utter frustration is real.

One reason that Target Display Mode has faded away could be a real, tech hardware issue: retimers required to drive the High-DPI displays on recent Macs.

It's not a satisfying thread of speculation. And it's not even wrong: all 2020+ Macs support Thunderbolt, the whole point of which is to drive DisplayPort and PCIe over the wire...

How hard could it be, to get a Mac to just run as a ThunderBolt screen?

So the next thing I considered was Thunderbolt, DMA, PCIe, and security.

The new Mac hardware has tried very hard to protect the machine from data exfiltration. You can fall through the rabbit hole at the great Eclectic Light blog, but anyhow it can seem needlessly complex, and yet full hardware encryption while supporting system updates out in the world is challenging. I've been unable to brick my MacBook, so far, so that's an improvement.

I am dropping off my 27-inch iMac for recycling next week. It's not a retina model, and I did use it as a target display, but mounting hardware age (I replaced the motherboard etc myself) have rendered it to be too much work to deal with. It's 12 years old, that's almost good enough for me.

I also came here to ask more or less this question. I have an old HP fixed frequency monitor (https://www.hpmuseum.net/display_item.php?hw=208) that I want to connect to a Raspberry Pi, and its not clear how to achieve this.

Seems you have separate RGBHV on the monitor side. See

[·] https://en.wikipedia.org/wiki/Component_video

To get that from your PI's HDMI you'd need something like

[·] https://www.amazon.com/Portta-3-5mm-Audio-Converter-support/...

and then something like this

[·] https://www.monoprice.com/product?p_id=562

Then you'd construct a custom Modeline like described in

[·] http://howto-pages.org/ModeLines/ &

[·] https://tldp.org/HOWTO/Framebuffer-HOWTO/

for I guess 1280x1024@60Hz? Maybe you don't even need to, because that is a common VESA resolution(SXGA) which should be provided anyways? So by setting this as fixed resolution by whichever means at startup, it could work. Maybe there are a even a few different ones to choose from, with slightly different timings, polarities. Or you could change that at the monitor itself. The second pdf from your link suggests that. I mean if the picture is rolling slowly up or down, or something like that.

I don't use PIs, so I don't know how the firmware works, which modes it supports, and how this all interacts with that videocore-thing, nowadays.

But that you'd need the converter gadgets and cable from there is obvious.

It's a bit bulky, but here's a setup which will work universally, but mind you, there will be some loss in resolution:

https://www.ebay.com/itm/144500108815?hash=item21a4e0ae0f:g:...

Check that out - RCA plugs, but as well a coax output, and another adapter to go coax > rabbit ears.

The only use case missing is getting RF out to an RCA connector.

...And of course the tripod.

I bought an Apple ][e recently at an estate sale. Loved playing with it and worked fine at the sale, but failed (monitor is fine but main board no longer turns on, no hard drive grind on startup, etc) after ~15 minutes of use. I found some troubleshooting manuals and got, then replaced, a bunch of main board chips. Still no luck, so I replaced the PS.

So I’m giving up my sunk costs on getting this actual Apple ][e into working shape, but I’ve decided to settle for hollowing it out as a sort of classic computer arcade cabinet? (with the help of a apple-keyboard-connector-to-USB dongle I found online), putting in a rpi4, and perhaps running an emulator to start (since I’ll be specifically reharnessing the original keyboard). This means I’ll trash the main board (and perhaps disk drive enclosure, which I have no use for) and also need to find a flatscreen to very safely and carefully put into the A2M2010 monitor enclosure after removing the CRT component (lovely green phosphors, sad I won’t get to see more of it).

Anyways, all of this is to say that this device is lovely and I might get when if another piece of classic hardware falls into my possession. :)

If you're in Europe I'd be happy to repair it for you, using it as an enclosure is a real waste.

don't trash it, put it in a closet for a while until you want to (or find someone who wants to) learn electronics troubleshooting.

You'll regret trashing it in a few years.

Ditch the RPi4 emu idea and get a Mister FPGA. It’s wonderful for retro computers as well and arcade and console games.

Don't trash it - many vintage computers need simple repairs before they'll work.

Spend a few hundred dollars and find someone to recap it and get it going for you again.

An old Apple 2 is a classic machine - it shouldn't be trashed. At worst sell it on to a collector for parts.

Please don't "trash" old parts! There are people who will pay you for the parts (and some will even come and take them off your hands so you don't have to mess with shipping). Apple IIe's and Disk II's aren't particularly rare, but there aren't ever going to be any more made.

If you aren't going to use the internals please offer them to someone on craigslist or local vintage computer shop, as this stuff is more and more rare every day because people just throw it in the dumpster. You can probably get some money even for non-working stuff.

For anyone else heading off on a similar voyage: it's almost always the power supply. And then the faulty power supply kills the ICs.

Electrolytic capacitors are unpleasant things. They require a liquid that slowly evaporates. They're temperature sensitive. Degraded ones behave erratically when they warm up, temporarily behaving and then not. And they can, worst of all, fail short. Quite possibly why your Apple's resurrection was temporary. I'd be more surprised if there wasn't a bang and magic smoke dissipating after turning on a PSU that had likely been off for 30+ years. Always replace or reform them in equipment of that vintage.

I don't know how it compares, but many of the retro computer channels on Youtube (Such as Adrians Digital Basement) use and speak highly of the RetroTink 2X($130) or 5X($300) pro:

https://www.retrotink.com/product-page/5x-pro

Which can handle: Composite (shared with green RCA jack), S-Video, Component, RGB and Composite on SCART connector, inputs.

I recommend the retrotink devices - specifically the 2x PRO and 2x SCART which are very simple, very tightly focused devices.

I have an RGB modded SNES connected with 21-pin to (modern HDMI) and it looks amazing.

If you have more exacting requirements or want a lot of configuration flexibility the OSSC may be a better choice but if you know exactly what your input/output is and it is supported, get the simple retrotink device.

I have a RetroTink 2X and it's amazing for the price. In addition to the physical connectors you mention it can handle certain cases that are hard:

1. can switch between 240p and 480i

2. Can switch between notch and 3D comb filter

Certain "not quite valid" outputs will not work with a 3D comb filter, but will work just fine with a notch filter.

The only downside is that sound from some devices (most notably the Sega Genesis, but possibly others) doesn't work over HDMI; as long as whatever you are putting your sound through has an analog input that's a non-issue though.

I can attest that the Retrotink 2X mini works OK for connecting a Commodore 64 to a modern (HDMI) display. Though, there are some oddities... ideally, I'd like to just use it for the video signal, and let the audio go straight to speakers, but the video often gets messed up when I do that. The audio signal also becomes unusually strong. (Going through HDMI I can at least dampen it somewhat, although it seems to lose a good deal of bass)

Probably some subtlety about voltages that I don't get about these ancient electronics.

See also the RGBtoHDMI: https://github.com/hoglet67/RGBtoHDMI/wiki

I have one of these and highly recommend it. Do note it is expressly for converting older digital signals to HDMI though. MDA and CGA are really difficult to find displays for these days, since even old CRT monitors have trouble with vsyncs lower than what VGA uses. And of those, the ones still in working order are exceptionally rare.

Trying to figure out how this is different from an OSSC - I guess it gives you composite/svideo - the big question in my mind is if it's easier to configure. The OSSC is powerful, but there's a lot of fiddling around with the raw primitives defining the input and output signals (which can be a good thing, if you're into that).

Fiddling is generally only needed if you want pixel perfect output. Else you get OK results, which are the same OK results you'd get with a less flexible solution.

Fortunately, most of the figuring out for perfect timings has already been done by other people. I was able to just input someone's numbers for my A1200. The results look positively digital, as if there was no analog step whatsoever in the chain.

I wanted pixel perfect output. It turns out this is a very hard problem for SNES, probably due to the 256×224 resolution not dividing nicely with anything. I ended up with a "pretty good" output, then a few months later more SuperNTs went on sale, so I got one of those. :) Some of the difficulty could have also been sensitivity with my monitor or capture card.

https://www.junkerhq.net/xrgb/index.php?title=Super_NES

There's a special sampling mode apparently.

I had this notion when HDMI was coming out that soon we might have the display of one device windowed into a larger display, like Picture in Picture but arbitrary.

Might have been some ideas stuck in my subconscious from the likes of Total Recall, but it seemed like we would be hitting a point where we stopped wanting to upgrade all of our devices every time we got a bigger TV with more resolution. We still see situations where we have monitors that we can't drive at full resolution and frequency from a single cable. So why not window in a 4k 60-120Hz feed and fill in the 'background' with a low frequency display (eg, a wallpaper and an information radiator), say 10k at 24Hz.

There are commercial products that do this for things like video walls.

No comments on this Medusa as I've never heard of it before, but for this task I've been using an OSSC, which definitely works well where I've tested it (mostly for my Megadrive) https://www.retrorgb.com/ossc.html

I wonder how it will treat the (a bit over 50Hz) PAL and (a bit under 60Hz) NTSC Commodore 64 s-video signals - will it generate a DVI signal at these rates, or adjust the frame timing by either tearing or skipping/duplicating as necessary.

This is a pretty cool idea.

Right now I have a small collection of mostly period-accurate monitors for my retro boxes and I prefer them for nostalgic and aesthetic reasons, but I'm under no illusion these will last indefinitely and CRTs can be difficult and a bit dangerous to repair. Eventually I'll want something like the Medusa adapter.

For what it's worth, I highly recommend Randy Fromm's four-part class on CRT repair on YouTube:

I watched it just out of curiosity, and now I can at least claim to know another useless skill now.

That whole channel is a goldmine of old school electronics repair. Thanks for sharing.

https://youtube.com/user/randyfromm

The best way to connect old composite/s-video devices to a modern screen is through the GV-USB2 japaneese capture dongle.

Very low latency so perfect for gaming. Resolution is too low for anything else really.

Unfortunately it only has official windows drivers that work (I found open-source linux ones, but havent tried them yet).

Lotharek does some really awesome stuff.

It'd be really cool if a device like this tried to simulate the CRTs that would be connected (blur, diffusion, persistence, composite color artifacts, etc) to the vintage equipment. With that, it'd be perfect to restore old equipment where the irreplaceable CRT needs to be replaced.

Sounds like Anchor Bay's DVDO iScan VP50 Video Processor from the old times:

https://atlona.com/pdf/DVDO_iScan_VP50_PRO.pdf

Need something like this to connect current gen HDMI devices to Apples thunderbolt only usb c monitors. Ended up returning the pro display xdr when I found out it was practically impossible to plug in hdmi devices.

There are HDMI to display port adapters and displayport to thunderbolt (the latter as a PCIe card). No clue if chaining them together works, but I've seen each work separately.

HDMI to displayport is already an active adapter which is complex and expensive. Stacking two active adapters together would be unreasonably expensive and I'd expect some noticeable latency.

Since the dot clocks are identical, it's feasible to implement with an amount of latency measured in lines, not frames; in fact I'd be surprised if there even was a frame buffer involved.

So, how much of this is hardware, and how much software? What’s the minimal hardware you would need, and how powerful a CPU would you need with it? Is this thing close?

It doesn't even support 13w3, so "old computers" doesn't include a lot of Unix workstations.

Does this thing actually exist?

There is no mention of recently released or upcoming alternatives that solve the same problem.

Another option that does analog -> analog conversion/upscaling/frame doubling: https://github.com/ramapcsx2/gbs-control

Much less expensive than the OSSC or Retrotink products.

There's no mention of accepting interlaced video inputs. Does it?

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