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USB-C power for your Amiga 500, 600 and 1200

91 points| nickt | 2 years ago |retrousbpower.com | reply

66 comments

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[+] jjice|2 years ago|reply
The move to USB C as a generic DC power standard is fantastic, at least as a consumer. I'm 100% on the USB C bandwagon. Even my coffee scale and room temperature gauge charge through USB C. Going from the days of eight different poorly designed AC->DC adapters with barrel jacks, this is heaven.

USB PD has it's quirks, that's definitely true, but I'll take it over the alternatives any day if I can use it on all my devices.

[+] linsomniac|2 years ago|reply
I am generally in the same boat, but I'll admit that I love my Macbook which can charge over either USB-C or the Magsafe (with USB-C at the other end), because I basically never worry about breaking the power connector when I'm using the Magsafe, but can still charge over USB-C as well.
[+] jackhalford|2 years ago|reply
Funny I just replaced the power port on my 2011 thinkpad with a usb c port (https://www.tindie.com/products/mikepdiy/lenovo-charging-por...). I guess as long as fundamentally the charging standards don’t change we’ll be able to do this with ever increasingly old tech.
[+] kramerger|2 years ago|reply
Didn't know this was possible!

I have a bunch of old thinkpads and need to keep around 3 different chargers (round, rectangular and usb-c). Could be great to go all in USB-C at some point.

[+] hbossy|2 years ago|reply
Why on Earth would you want to replace the robust, round connector with fragile USB-C?
[+] bjelkeman-again|2 years ago|reply
One of the few computers I regret getting rid of is my Amiga 500. What would I use it for? Not sure. But… Something.
[+] finnjohnsen2|2 years ago|reply
If you go after it and buy an Amiga, don't forget it is much about preserving a vintage computer at this point. And not just the computing/gaming or whatever you remember doing.

I did this, and I'm not sure it was what I wanted.

[+] andoma|2 years ago|reply
I don’t miss my old Amiga that much. But I do regret that I didn’t keep copies of source code for various projects I did on the Amiga. Mostly for nostalgic reasons of course.
[+] ElCapitanMarkla|2 years ago|reply
I saw our old A600 in storage at my parents last weekend. I’ll go get it one day, so many good games on there.
[+] BallyBrain|2 years ago|reply
Oh man, I did the same thing and very much regret it. It's like I gave away a important part of my childhood. When I have the time I'll buy another one and probably just fiddle around with it. Play all the old games I used to like too I guess.
[+] stuff4ben|2 years ago|reply
I threw out my 2 A500's into the electronics recycling when I moved houses 15 years ago. I wish I had kept them now that I have the space. I didn't have a monitor though since my 1084s was busted so I never used the computers.
[+] gardaani|2 years ago|reply
An interesting detail is that it has a physical switch to turn it off.

> Utilizing any 12V-capable USB-C power supply

Are different kind of USB-C power supplies, some not outputting 12V? Does it mean that normal phone chargers aren't good?

[+] gbraad|2 years ago|reply
Some chargers don't do 12V or 15V, but will do 5V, 9V and 20V. This depends a lot on the total wattage. Lower watts, like 20W or 30W can or can not do 15/20V, but [email protected] (18W) and [email protected] (30W). Usually the >65W will do most of them, plus PPS. Always check specs. And what is the input voltage this powerplug expects; 15V or 20V?

> Utilizing any 12V-capable

If so, this is usually at a VERY low wattage. they usually go to a max of 2.5 or 3A max at 12V. I would expect it would use 20V and step-down as 20V is more generally available at a high Amperage. (Note: 3A is the max possible for cables without an E-marker, os if often regarded as a ceiling). This would have made the device much bigger (and more versatile. a clear trade-off).

Actually, I am more concerned about -12V, ... at 0.1A. That seems rather low. Also, the 12V rail itself is only 1.0A. The original supply did 12V@2A and [email protected] if not mistaken, and so does the C64psu.com. Overall, rather low Amp values. This might affect 'stability' if your machine is expanded (although it claims: "of even the most expanded configurations"). Curious if they can share some details. I have a BlizzardPPC in my A1200.

> allows users to tap into a vast array of affordable and readily available “power bricks”

if DC5521 at >12V to 20V is possible, that would be great, as this allows you to use a Lenovo or generic laptop brick, or a USB-C trigger cable. Perhaps something I should make ...

[+] fragmede|2 years ago|reply
Yes. Your random usb-c phone charger may not do 12 or 20 volts. It only needs to do 5 volts to charge a phone. A usb-c laptop charger will do more volts and amps which means more watts.
[+] unwind|2 years ago|reply
It might also be a way to indicate that you can't just use a USB A-to-C "charging" cable, and connect it to an old-school 5 V-only USB adapter. It needs the modern power-delivery things which are only available over USB C.

There was (that I could find, and I did go back to check again) no mention of price other than "TBD", which probably means it's not aiming to be a cheap solution. Trying to guesstimate but it's hard, I'm not enough "into" the Amiga retro scene. $99 feels like too much ... $79?

Finally, I found the copy on the site a couple of generous notches above 10 and really think it would help to tone it down just a little. But maybe that's just me being grouchy, as someone who grew up on Amigas it's really great to see this kind of development and continued interest in the machines! Good luck!

[+] Findecanor|2 years ago|reply
> An interesting detail is that it has a physical switch to turn it off.

It is the switch for turning the computer on. The original power supplies all had it on the box.

I had my power supply on the floor under the desk and was used to flipping it on and off with my foot. I used the heavy supply from my A500 with a A1200 later.

[+] rob74|2 years ago|reply
I imagine the physical switch and the grilles are a tribute to the original power supplies (A500: https://i.ebayimg.com/images/g/wbYAAOSwW1JlX0FB/s-l1600.jpg). The site doesn't give any hint about the color, but I would bet it will be beige...

That being said, the claim that it works with "any 12V-capable USB-C power supply" sounds very ambitious. Is any 12-V capable USB-C power supply capable of delivering 60+ watts?

[+] LeoPanthera|2 years ago|reply
In fact, most don't do 12v. The common voltages are 5, 9, 15, and 20 volts.
[+] rpaddock|2 years ago|reply
Invest in a STM32G0 Discovery Kit for about $60. It tells you exactly what your USB-C power cube is capable of putting out.

So far I've only found one 35W Samsung cube that meet the spec of putting out 3.1V to 21V.

Most only put out one or two of the voltages of 9V, 12V, 15V or 21V. The 15W and under are usual 9V or 12V, with one being 15V. All will always default to 5V.

https://www.st.com/content/ccc/resource/technical/document/d...

[+] mbirth|2 years ago|reply
And watch out for weird pseudo-USB-C chargers. I’ve read about some cheap power tools being sold with “USB-C charging”. But they merely used the plug as a selling point. The AC adapter was a bog standard one and always sent 12V to the USB-C plug. So you’d fry any normal USB-C device you plug this into.
[+] MenhirMike|2 years ago|reply
This is awesome, especially since Commodore power supplies do have a reputation for not being the best quality ones. This is more of an issue on the Commodore 64 where you should NEVER use the original power supply anymore because it's playing russian roulette. I'm not sure if the Amiga 500 power supplies were equally prone to frying your system and I'm hoping that by 1992 they got it sorted out, but still, better be safe than sorry and not risk anything.
[+] danby|2 years ago|reply
As I understand it the issue is that when the old c64 power supplies failed the 12v line would go overvoltage and fry your computer. The amiga power supplies are designed differently and don't have this "feature".

Though it is often worth replacing the original amiga power supplies as the capacitors are often shot by this point

[+] amiga386|2 years ago|reply
When I used to power my Amiga 1200 with an ATX power supply, you could power it "in reverse" by _supplying_ +12V and +5V to the floppy disk power connector on the motherboard. But for proper operation, you also needed -12V, and that had to come from the ATX motherboard plug and go into middle hole of the Amiga's power socket.

Could any electrical engineers here explain how one gets both +12V and -12V output from a +12V input?

[+] NullPrefix|2 years ago|reply
Blue pin on the ATX motherboard plug is -12V.

I assume the PSU isn't making -12V from +12V. It's making both of them from whatever the AC is

[+] hbossy|2 years ago|reply
You boost it to 24V and then use 12V as GND, 24V as +12V and actual GND of supply as -12V.
[+] speed_spread|2 years ago|reply
-12V is to make the strong zeroes. Hardened voids are a forgotten art in this age of USB-positive softness.
[+] snvzz|2 years ago|reply
This is going to be a simple yet very convenient piece of hardware.
[+] Keyframe|2 years ago|reply
Question is whether it will be able to run Amigas with accelerators inside? That usually required beefier 6A PSU
[+] dark-star|2 years ago|reply
Apparently they demoed it on Amiga38, powering an A1200 with a '040 accelerator and/or PiStorm card, card and that was no problem. I have not seen nor done the actual maths, but since it's done by actual Amiga community people and not some shady Chinese company, I would say it's safe to assume they considered these use cases.