model m leds blinking when overloaded with keypresses?

[gianni]

I've recently purchased an ibm model m 1391403 from 1996, more or less NOS.
Sometimes, the three leds start blinking at the same time, then the keyboard stops registring keypresses for a second or two, and then everything goes back to normal.

Why does this happen? The keyboard is a ps/2 and I connected it to an usb port with a passive adapter. The issues happens with all the usb ports that I've tried until now.

[Weezer]

Does it do the same thing when you unplug the keyboard and plug it back in?

[zzxx53]

Sounds like the keyboard got reset for some reason, a loose connector perhaps?

[Inxie]

A PASSIVE adapter? I am 99.9% certain that model of Model M does not speak USB, so you'd need be using an ACTIVE adapter.

Either way, that happens a lot of times with cheap USB adapters. I have several of them that do this very thing. Notice that the LED flashing sequence is identical to when you power on the computer. The keyboard is being reset because the converter failed to handle what you asked of it (why, I don't know, maybe it's a rollover thing or a sequence of keys in particular). I have two here in particular that are weird with both Model M's and AT101W's. One with Model M's does this, it resets if you aren't careful (since we're talking 2-key rollover here, and I think it's the rollover that's causing the reset), and another with an AT101W where each arrow key also types Print Screen for some odd reason. They are garbage converters.

The only adapter I ever used that actually worked 100% was the blue cube one. But Soarers works with PS/2/AT scancodes as well, so honestly even just using that could be a far better alternative. I'm using a Soarers with an XT Model F, but I was able to beat Doom Eternal without one hiccup.

[gianni]

Sorry, I thought that my adapter was passive, but now I see that in the description it is probably active.

Anyway I had the blinking leds problem on all the usb ports. It happens about two times a day.

https://www.amazon.com/StarTech-USB-PS- ... B00028OP2Y

"StarTech.com USB to PS/2 Adapter for Keyboard and Mouse - Keyboard / mouse adapter - USB - USBPS2PC, Black "

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[gianni]

... The keyboard is being reset because the converter failed to handle what you asked of it (why, I don't know, maybe it's a rollover thing or a sequence of keys in particular). I have two here in particular that are weird with both Model M's and AT101W's. One with Model M's does this, it resets if you aren't careful (since we're talking 2-key rollover here, and I think it's the rollover that's causing the reset), and another with an AT101W where each arrow key also types Print Screen for some odd reason. They are garbage converters.

Probably you're right about the rollover, because it happens when I'm typing quite fast, so maybe this behaviour can trigger some kind of involountary multi key rollover.

[Coeus]

Probably you're right about the rollover, because it happens when I'm typing quite fast, so maybe this behaviour can trigger some kind of involountary multi key rollover.

Key rollover pre-dates the concern about lots of modifiers or games where each key is effectively an independent control and was for allowing the downstroke of one key to precede the upstroke of the previous key.

Interesting that your converter is s StarTech. I have a StarTech KVM that doesn't play well with keyboard converters as that is doing something weird with the USB connection for the keyboard. Firstly, it is listening in to detect a hotkey sequence, then it doesn't disconnect/reconnect that USB device when switching PC. The symptoms are it doesn't handle NKRO properly and sometimes the keys will do weird things after switching PC. Either way I am beginning to wonder if this firmware fully complies with the relevant standard.

For At protocol keyboards I have one of these:

20200831_133039_1044.jpg (193.93 KiB) Viewed 2887 times

20200831_132505_1039.jpg (197.32 KiB) Viewed 2887 times

which seems to work fine, though I have not tried it on a Model M. For my Model F I started out with Soarer's converter which works fine, except with the KVM, but I am now using TMK which seems to work better with the KVM.

[Inxie]

Ah HA! My adapter is a Star Tech as well that does the resetting. It is however an older looking version that was designed for Macs (so it has the Apple translucent look of the day), but a Star Tech, and it is the one that resets with certain key combinations. (Up Left at the same time with my AT101W would trigger a reset for example).

It's basically just a bad converter if it isn't the keyboard itself, and no USB port change will help. Just need a better converter is all.

[Inxie]

For my Model F I started out with Soarer's converter which works fine, except with the KVM, but I am now using TMK which seems to work better with the KVM.

Out of curiosity, did you try the latest firmware with Soarer? I know he fixed some issues with buggy BIOS's, and that refers to a specific HID boot mode (where no nkro is enabled), and the KVM may want that 6kro limit of the standard USB HID spec that the newer firmware has for boot/post mode.

[gianni]

Ah HA! My adapter is a Star Tech as well that does the resetting. It is however an older looking version that was designed for Macs (so it has the Apple translucent look of the day), but a Star Tech, and it is the one that resets with certain key combinations. (Up Left at the same time with my AT101W would trigger a reset for example).

It's basically just a bad converter if it isn't the keyboard itself, and no USB port change will help. Just need a better converter is all.

thank you, I needed a confirmation. Time to leave a bad review on amazon!

[Weezer]

A recommendation for a cheap converter that will work is "Monoprice".

Something that may have been overlooked here is that there could be an issue with the keyboard cable. Be sure that the keyboard cable is sound and that the controller doesn't have signs of water damage before spending 40+ on/putting hours into making a soarer's

[gianni]

A recommendation for a cheap converter that will work is "Monoprice".

An issue that may have been overlooked here is that there could be an issue with the keyboard cable. Be sure that the keyboard cable is sound and that the controller doesn't have signs of water damage before spending 40+ on/putting hours into making a soarer's

Thanks, so you recommend this one:

https://www.amazon.com/Monoprice-Keyboa ... B00IACID2C

which is a rebranded one with many variants
https://www.amazon.it/Perixx-peripro-40 ... 008DFVQFW/

I can confirm that the resets happens, without regularity, with some key combos, for example arrow plus shift etc.

[Weezer]

Yeah that's the one I use. I have 3 of them and I've never had any problems.