What kind of usb connector is this? - Page 1
Forum section: electronics / beginners

author: cds333
author_rank: Contributor
timestamp: March 25, 2022, 02:29:31 am
content: Appears to be a standard female USB A, but has a little metal v shaped protrusion to prevent standard male connectors from connecting. Found one that looks like an Apple product (no logo but same style and color) and one with no markings.Tyvm!

author: oPossum
author_rank: Super Contributor
timestamp: March 25, 2022, 02:34:05 am
content: Extension cable for an apple mouse that has the mating connector. Extension cables are not allowed by the USB spec so they made a cable that can't be used for standard USB peripherals.

author: cds333
author_rank: Contributor
timestamp: March 25, 2022, 02:40:32 am
content: Awesome! Thank you for the quick answer.When you say "Extension cables are not allowed by the USB spec" are you referring to apple products of that era only? Because I have seen standard USB A male to female extenders for years.

author: oPossum
author_rank: Super Contributor
timestamp: March 25, 2022, 02:47:47 am
content: It is not allowed by the USB specifications of the USB Implementers Forumhttps://www.usb.org/There are various cables that are not allowed but are manufactured. USB A to A is a common example.

author: tooki
author_rank: Super Contributor
timestamp: March 25, 2022, 12:09:27 pm
content: Quote from: oPossum on March 25, 2022, 02:34:05 amAlmost. It’s actually for the keyboard. The mouse has a standard (non-keyed) USB plug on the end of a fairly short cord, and plugs into the standard USB port on either side of the keyboard. The keyboard, in turn, has the notched plug that fits into a standard USB port or into these extension cables.These cables (well, an earlier version) first shipped with the blue and white Power Mac G3 minitowers, since the keyboard’s built in cable was also deliberately short, for use with the iMac and when the Power Mac is on the desk, while the extension is intended for when the Power Mac is on the floor. I had one of those blue and whites.People who used a third-party keyboard with their Power Mac, but used the Apple mouse, often forced the mouse plug into these extensions, permanently (but harmlessly) deforming the mouse’s connector shell. I saw a lot of those in the field.

author: Old Printer
author_rank: Frequent Contributor
timestamp: March 25, 2022, 12:56:08 pm
content: I don’t remember about the usb cable but I had a couple of those blue and white Macs in my print shop. I remember thinking they had some great industrial designers at Apple, as compared to the black box’s PCs came in. They were just beautiful to look at. Apple/Mac and Adobe owned the graphic arts world back then. The imagesetters were only available with Mac interface cards, a bit frustrating for a PC guy, but they worked lights out.

author: Berni
author_rank: Super Contributor
timestamp: March 25, 2022, 01:26:42 pm
content: Quote from: oPossum on March 25, 2022, 02:47:47 amI had no idea extender cables are not allowed. The A to A cable is obviously a bad idea and should not be made, but a extender cable sounds pretty harmless. Only problem might be chaining together way too many extender cables to the point where it stops working (garbled data or supply voltage sag)I even seen USB extender cables included with some peripherals from big companies like Microsoft(Xbox) or Valve. They meant to be used to locate a wireless controller receiver dongle into a spot where it has better reception (In case it is deep buried behind a desktop PC). Pretty sure i used that extender for other stuff and didn't notice any keying to prevent me from doing it.

author: tooki
author_rank: Super Contributor
timestamp: March 25, 2022, 01:52:15 pm
content: Quote from: Old Printer on March 25, 2022, 12:56:08 pmHonestly, those machines just rocked from an industrial design standpoint. They (and the G4 models in the same general enclosure) were a very common model during the time I was working as an (indie) on-site Mac consultant, so I worked on them a lot. Handles to carry them by? BRILLIANT. The logic board on the door that just swings down, making RAM and expansion card upgrades super easy? GODDAMNED GENIUS!!Though it’s an aesthetically gorgeous design, I was disappointed when the Power Mac G5 came out, in that its logic board is screwed into the case together with everything else, much like a typical PC. Great machines though!

author: tooki
author_rank: Super Contributor
timestamp: March 25, 2022, 01:58:51 pm
content: Quote from: Berni on March 25, 2022, 01:26:42 pmYeah, I have a Logitech mouse that came with an extension like that. Indeed, I have never seen anyone but Apple provide a keyed extension. I guess it was just CYA. When the first USB Macs came out in 1998-1999, USB devices were still very fickle. Cable quality mattered a TON, many devices wouldn’t work with extensions or hubs, etc. I think the USB chipsets have gotten a lot better, and I believe the USB specs — even for low speed and full speed — have been tightened up in some regards to ensure good performance.(And let’s not get started on how bad the very early USB drivers were…)

author: tooki
author_rank: Super Contributor
timestamp: March 25, 2022, 02:03:05 pm
content: Fun fact about the earliest USB Macs: their keyboards had hardware power buttons, just like the ADB (Apple Desktop Bus) keyboards of older models. The keyboard power button shorted one of the USB data lines to ground when pressed, and the slightly modified USB controller used this (together with the 5V standby supply) to power the system on, without needing to have the USB stack running.

author: oPossum
author_rank: Super Contributor
timestamp: March 25, 2022, 02:06:33 pm
content: Big companies sometimes use prohibited cables. I have an Atmel programmer that uses an A to A cable.A 1 port USB hub with a captive cable is allowed by spec. That is what some extension cables are.

author: tooki
author_rank: Super Contributor
timestamp: March 25, 2022, 03:57:48 pm
content: Quote from: oPossum on March 25, 2022, 02:06:33 pmPictures of an almost certainly uncertified (based on the janky USB logos on the packaging and device) no-name active repeater don’t really tell us anything. It certainly does not provide evidence of the existence of a spec.I challenge you to find the relevant section of the spec that allows for 1-port hubs. Because I can’t find anything to that effect.

author: magic
author_rank: Super Contributor
timestamp: March 25, 2022, 05:07:33 pm
content: Heh, good question.There is this in the section on self-powered hubs:QuoteSo I suppose it could be anywhere from 0 to 255, as this is the numerical range available in the protocol.Any hard proof that a zero port hub is not compliant?

author: tooki
author_rank: Super Contributor
timestamp: March 25, 2022, 05:33:48 pm
content: Quote from: magic on March 25, 2022, 05:07:33 pmThanks! At first glance, I would agree with your interpretation.Quote from: magic on March 25, 2022, 05:07:33 pm

author: Bassman59
author_rank: Super Contributor
timestamp: March 26, 2022, 06:13:16 pm
content: Quote from: cds333 on March 25, 2022, 02:40:32 amPassive extension cables are not allowed because it is possible to chain them together and get a cable length that exceeds the USB spec of 5 meters. Of course that doesn't stop anyone from making such cables.Active extension cables have a built-in hub which acts as a sort of repeater.

author: tooki
author_rank: Super Contributor
timestamp: March 26, 2022, 08:47:37 pm
content: Oh yeah, I meant to attach this picture yesterday. This is what the mating male plug on the keyboard cable looks like.