I’ve made a Cursed USB-C 2.0 device • Hacker News Board

Re: I’ve made a Cursed USB-C 2.0 device

#81

Post by drewzero1 » Mon, Mar 22, 2021, 4:23 PM UTC

chaorace wrote: post #50

Theodores wrote: post #39

Earlier quoted context omitted.

Given that this is the only practical application you have to wonder why we ever had the one way plugs in the first place.

Two major reasons, as far as I understand things. Firstly, reversible plugs are harder to make structurally resilient, they only become feasible cost-wise as stronger materials become cheaper and manufacturing grows more efficient. Secondly, reversible plugs are a lot more complex. Compare the 4(ish) pins of USB-A to the 24 pins on USB-C. Not all of them are strictly necessary for parity with USB-A, but you could cut…

This! Even just comparing USB-A 1.0 to what it replaced, it's hard to imagine a reversible plug like USB-C having been feasible/cost-effective to produce in the mid 90s. The PS/2 mouse and keyboard ports had pins of a similar size and spacing, but it was hard to orient the circular connectors. You could get the connector lined up and twist gently until the pins found their holes, but eventually you would bend a pin. I remember being very impressed at the way USB solved the issue of bent pins, but wondering why they didn't just key the connector like a Zip disk (which had beveled edges along the top of the disk, and wouldn't go into the drive upside-down).

Meanwhile we were connecting printers, scanners, and other peripherals using a 25-pin parallel (or sometimes SCSI) plug. Granted, the DB-25 was already pretty old at that point, but I have to imagine a 24-pin reversible USB plug would have been close to that size if it had been developed in the 90s.

Re: I’ve made a Cursed USB-C 2.0 device

#82

Post by reaperducer » Mon, Mar 22, 2021, 4:29 PM UTC

magicalhippo wrote: post #38

Hnaomyiph wrote: post #4

I feel like USB-C is cursed enough on its own. The sheer number of times I’ve had to explain to family members why just because the two USB-C ports on a laptop look the same, doesn’t mean they work the same.

> just because the two USB-C ports on a laptop look the same, doesn’t mean they work the same. This is already a solved problem[1] through color coding. Not sure why they couldn't use that scheme. Maybe combine a few to indicate things like DisplayPort and Thunderbolt capability, could have up to four quadrants for example. [1]: https://en.wikipedia.org/wiki/PC_System_Design_Guide#Color-c...

This is already a solved problem[1] through color coding

You would think so, but no. Colors don't help.

Not just because a good chunk of the population has color vision issues. But people for some reason the average person can't latch onto that sort of thinking.

We went through this back in the 90's. Your PS/2 mouse plug was one color, and the PS/2 keyboard plug was another color. But people still tried to stick them in the wrong places.

Same with the sound card. Microphone, speakers, line in, line out, all had their own colors that matched the wires that came in the box. Regular people screwed that up all the time.

Going further back to the 70's and 80's, if you looked at the back of anyone's rack system, there was a 50% chance they had the red/white pairs of RCA plug backwards. Then when video started getting carried over the same plug, but colored yellow, things got worse.

Re: I’ve made a Cursed USB-C 2.0 device

#83

Post by Kuinox » Mon, Mar 22, 2021, 4:30 PM UTC

chaorace wrote: post #50

Theodores wrote: post #39

Earlier quoted context omitted.

Given that this is the only practical application you have to wonder why we ever had the one way plugs in the first place.

Two major reasons, as far as I understand things. Firstly, reversible plugs are harder to make structurally resilient, they only become feasible cost-wise as stronger materials become cheaper and manufacturing grows more efficient. Secondly, reversible plugs are a lot more complex. Compare the 4(ish) pins of USB-A to the 24 pins on USB-C. Not all of them are strictly necessary for parity with USB-A, but you could cut…

> Compare the 4(ish) pins of USB-A to the 24 pins on USB-C

This is misleading.

If you want to only cover the USB-A spec with USB-C, you need only 8 pins.

I have a cheap USB C on my desk that got 8pins because it do only USB and charge.

USB-C can pass HDMI signal on the other pins, which your USB-A can't do.

Re: I’ve made a Cursed USB-C 2.0 device

#84

Post by m463 » Mon, Mar 22, 2021, 4:31 PM UTC

weinzierl wrote: post #16

Now I want a USB-C thumb drive that has different data on different sides. Like the old 5 1/4" diskette drives where you flipped the disk for double capacity. Using it for retro-gaming would be fun. When the game says "Flip the Disk" you flip the USB drive.

what about an input side and an output side?

One is Read Only Memory, the other is Write Only Memory (the holy grail)

Re: I’ve made a Cursed USB-C 2.0 device

#85

Post by m463 » Mon, Mar 22, 2021, 4:34 PM UTC

avian wrote: post #48

Hnaomyiph wrote: post #4

I feel like USB-C is cursed enough on its own. The sheer number of times I’ve had to explain to family members why just because the two USB-C ports on a laptop look the same, doesn’t mean they work the same.

I find it funny how people used to complain about the sheer number of times they had to explain to family members exactly the opposite: "No need to ask. If you can plug it in, then it will work. Computers are fool-proof like that. No, it's not like the jacks on the hi-fi" As in, someone got a new mouse and didn't know where to plug it into their computer, when in fact there was only one DB-9 connector on the computer…

Didn't DB-9 also work for early video before VGA?

Re: I’ve made a Cursed USB-C 2.0 device

#86

Post by chaorace » Mon, Mar 22, 2021, 4:35 PM UTC

Kuinox wrote: post #83

chaorace wrote: post #50

Earlier quoted context omitted.

Two major reasons, as far as I understand things. Firstly, reversible plugs are harder to make structurally resilient, they only become feasible cost-wise as stronger materials become cheaper and manufacturing grows more efficient. Secondly, reversible plugs are a lot more complex. Compare the 4(ish) pins of USB-A to the 24 pins on USB-C. Not all of them are strictly necessary for parity with USB-A, but you could cut…

> Compare the 4(ish) pins of USB-A to the 24 pins on USB-C This is misleading. If you want to only cover the USB-A spec with USB-C, you need only 8 pins. I have a cheap USB C on my desk that got 8pins because it do only USB and charge. USB-C can pass HDMI signal on the other pins, which your USB-A can't do.

Sure, it's misleading. That's why the next sentence reads...

> Not all of them are strictly necessary for parity with USB-A, but you could cut that number in half quite easily if the plug were not reversible

Is 4 not half of 8?

Re: I’ve made a Cursed USB-C 2.0 device

#87

Post by gh-throw » Mon, Mar 22, 2021, 4:35 PM UTC

justusthane wrote: post #73

When I worked help desk, I once found a USB mouse that instantly killed any computer it was plugged into. Instant power off. I also found a laptop power supply that would cause the CPU of whatever machine it was plugged into to run at 100MHz. That was a fun one to troubleshoot.

10-to-1 that mouse had a really nasty short in it somewhere.

Re: I’ve made a Cursed USB-C 2.0 device

#88

Post by fennecfoxen » Mon, Mar 22, 2021, 4:40 PM UTC

techrat wrote: post #69

floatboth wrote: post #60

Google makes "cursed" devices in production :) The Chromebook debug functionality is only accessible in one orientation: https://chromium.googlesource.com/chromiumos/third_party/hdc... (but that's with a special cable)

Can confirm. Suzy Q cable. SparkFun sells one. Had to diagnose a Pixelbook that got bricked on an update that Google was refusing to warranty. Thought the cable was bad before someone in Discord suggested that I flip the plug. Still not sure how I feel about a reversible plug having a specific orientation.

You feel terrible about it. The question is how terrible.

Re: I’ve made a Cursed USB-C 2.0 device

#89

Post by chaorace » Mon, Mar 22, 2021, 4:41 PM UTC

buran77 wrote: post #80

chaorace wrote: post #50

Earlier quoted context omitted.

Two major reasons, as far as I understand things. Firstly, reversible plugs are harder to make structurally resilient, they only become feasible cost-wise as stronger materials become cheaper and manufacturing grows more efficient. Secondly, reversible plugs are a lot more complex. Compare the 4(ish) pins of USB-A to the 24 pins on USB-C. Not all of them are strictly necessary for parity with USB-A, but you could cut…

A standard USB 3.1 type A connector has 9 pins. The reversible type C has 3 extra pins (SBU, CC, VBUS), not counting the doubling caused by making it reversible. So while the reversibility doubled the number of pins, the increased complexity of the standard itself tripled it (from 4 to 12).

Good catch. I should have either compared the 9 pins of 3.1 or been more specific in saying 4 pins for USB 2.

Fun fact: USB 2 Mini/Micro connectors actually have 5 pins (hence my original 4-ish statement). The 5th pin doesn't actually go over the wire, it's just used as a signalling pin to the controller that tells it if the plugged in device is compatible with USB OTG.

Re: I’ve made a Cursed USB-C 2.0 device

#90

Post by dspillett » Mon, Mar 22, 2021, 4:52 PM UTC

magicalhippo wrote: post #38

Hnaomyiph wrote: post #4

I feel like USB-C is cursed enough on its own. The sheer number of times I’ve had to explain to family members why just because the two USB-C ports on a laptop look the same, doesn’t mean they work the same.

> just because the two USB-C ports on a laptop look the same, doesn’t mean they work the same. This is already a solved problem[1] through color coding. Not sure why they couldn't use that scheme. Maybe combine a few to indicate things like DisplayPort and Thunderbolt capability, could have up to four quadrants for example. [1]: https://en.wikipedia.org/wiki/PC_System_Design_Guide#Color-c...

Not when there are many ports out there without the right colours. Or with the wrong colours. Or arbitrary different colours because some manufacturer has a "bright" idea on their own. Or where it doesn't matter (were the keyb/mouse ports generally interchangeable? I certainly had two machines where they were despite the colour coding and I've seen single ports with "key/mouse" iconography since).

Maybe if the next standard has colours to start with, and they are unambiguous, and somehow not even ambiguous if confused with a previous port version, and they are adhered to by all manufactures, consistently, and nothing new arrives that someone adds a colour for before the standards body makes a decision...