found this ADB switch...is it safe to use

[KennyPowers]

I just found this buried in a box:



I know hotplugging ADB is generally frowned upon and has even damaged some boards. I wonder if this thing is safe to use, or if it would change ADB bus IDs and screwball my mouse settings or something?

 

[YMK]

No idea. I'm wondering what the point of this device is, given ADB can address everything connected simultaneously.

Maybe you can convert it into something useful, like an ADB hub.

 

[Drake]

You should open it up so we can peek at it. There might be some logic and safety circuit for the purpose of switching BUT I can't imagine this was intended for peripherals like mouse/keyboard?

 

[Trash80toG4]

Badly misaligned, manual plugging when the system is hot would be what kills ADB Controllers.

ADB switching via rotary switch equipped manual KVM is just fine for switching ADB while hot. Though you do need to have ADBreset on the desktop at the ready to run it from the KBD. Mice tend to loose their way.

Open it up and lets see what's inside. You could use it to control three Macs with one KBD/Mouse, but without Monitor switching that would only work with a display having Mac, VGA and BNC inputs switchable on the front panel, unless of course AIOs are involved in the mix.

 

[lilliputian]

No idea. I'm wondering what the point of this device is, given ADB can address everything connected simultaneously.

Maybe you can convert it into something useful, like an ADB hub.

Presumably it would be for controlling multiple computers with a single mouse/keyboard setup. As Trash80toG4 says, a KVM (keyboard/video/mouse), but without the "V".

 

[lilliputian]

Any hint of a brand or manufacturer?

 

[KennyPowers]

No brand or manufacturer markings. These are the only mentions of this thing I've found online:

http://powermac6100.blogspot.com/2006/07/usb-optical-mouse-with-power-mac-6100.html
https://www.fixya.com/support/t102382-2_cpus_one_keyboard_adb

So apparently the model number was MD4-103. I tried to put that purchase url (http://www.welovemacs.com/md4103.html) into the Wayback Machine, but it's down right now.

I can't figure out how to open it without breaking it. There aren't any screws under the sticker on the bottom, and the two halves don't want to separate.

Yes, I was contemplating using this to share a single keyboard/mouse between two macs. They already share the same monitor via a VGA switch. Currently, I have separate ADB cables attached to both macs and I just attach the keyboard/mouse to the cable for the machine I want to use (with the machine powered off). However, if I'd have to mess with remembering to queue up a utility to reset the ADB bus when switching, then I think I'll just stick with my current arrangement.

 

[Trash80toG4]

Sounds like a plan to me!

The only other use case I can think of offhand might be for sharing the likes of an ADB hand scanner between three different users. A dedicated, central location for that would make sense with three workstations lined up in a DTP shop.

 

[KennyPowers]

Wayback Machine came back online. Here's the purchase page for this device from 2004:



I notice it doesn't mention keyboards or mice, so maybe this was meant for devices that were more tolerant of being connected/disconnected and didn't have pass-through connectors to continue the ADB chain? I'm no ADB expert though, so I don't know if that makes any sense.

 

[François]

Maybe it was for copy-protection dongles? Weren’t expensive software protected by ADB keys back in the day? I seem to remember it was the reason the Power Mac G3 retained 1 ADB port.

 

[KennyPowers]

I dunno...back in the box it goes though

 

[retr01]

Someone in Germany designed and manufactured ADB switch boxes that prevent the hot-swapping issue. I can't remember the name of it. I wonder if this small switch has a similar setup.

 

[KennyPowers]

Someone in Germany designed and manufactured ADB switch boxes that prevent the hot-swapping issue. I can't remember the name of it. I wonder if this small switch has a similar setup.

I think you're talking about the Dr. Bott MoniSwitch: https://lowendmac.com/1998/moniswitch-adb-a-kvm-for-adb-macs/

Apparently you could still have to reset the ADB bus sometimes if you moved the mouse too soon after switching.

 

[lilliputian]

Hmm, according to the original item description, despite being called a "switch", it's really more of an ADB hub than a KVM, which happens to have a switch for the various input devices:

"Connect up to 3 ADB devices to your Mac computer."

"Each ADB port will be able to access up to 3 devices."

"These Switches allow your computer to access ADB devices such as modems, printers, plotters, digital cameras, joysticks, and many more."

 

[retr01]

Interesting that it says ADB devices such as printers, plotters, modems, etc. Those peripheral devices use serial interfaces rather than ADB, right? How do those peripheral devices work with ADB when a serial connection is needed? I find that odd.

 

[KennyPowers]

Ya, I thought that was weird too. So far, the only "practical" use I've seen someone use this for is as a short extension when the ADB connector for their device physically interfered with the port they were trying to plug it into

 

[lilliputian]

There were non-serial devices that were ADB. Gamepads/joysticks and graphics tablets come to mind.

 

[lilliputian]

Not sure about Modems and Scanners, etc... They may have just been adding possibilities for marketing reasons.

 

[KennyPowers]

There were non-serial devices that were ADB. Gamepads/joysticks and graphics tablets come to mind.

Was it uncommon for these devices to have a female ADB input on them to chain other devices on like keyboards usually have? This joystick has a passthrough...

 

[lilliputian]

I believe that all the devices that I have do indeed have pass-through ports, so not sure.