Beamspring USB controller

[xwhatsit]

Good news everyone! It works

Here it is nestled in its home. You might note that the solenoid is loose; this is a 3727 keyboard, which don't come with solenoids. I stole the solenoid out of my 5251 (which lives at home), and left it sitting loose.

photo 1.JPG (151.13 KiB) Viewed 5168 times

And here is the fix (note green wire):

photo 2.JPG (96.14 KiB) Viewed 5168 times

Basically this hack implements a (crude!) switch-mode current limiter

The wire goes between the enable to the boost converter (bottom left), and the active-low fault output of the current limiter.

The boost converter's enable pin used to be connected to 5V all the time, so it was always powered.

Now what happens, is the current limit is hit, the fault output is pulled low 20-30ms later, which turns off the boost converter. The current of course drops instantly, and 20-30ms later the fault output idles high again, turning the boost converter back on. The cycle will then repeat indefinitely, as long as you still try to hold the solenoid in. Let go of the solenoid, and everything goes back to normal. Not even a little bit of heat! Runs cool as a cucumber.

Here is the fault output cycling while I press a key (then release it):

1.png (1.84 KiB) Viewed 5168 times

And here is the 9V, which drops down to roughly 5V while the solenoid is held in, and sits there cycling between 5V and 7V or so before I release the key and it charges back up again:

2.png (2.77 KiB) Viewed 5168 times

I need to polish off the firmware a bit more to properly test it (it's only firing off the LShift key at the moment as a quick hack); hopefully it'll hold up under fast typing. But looking good so far.

[quantalume]

So you're sure I can power this thing from my tablet?

[nourathar]

great development !

[Daemon Raccoon]

Very nice work, now I just need to get my hands on a Beamspring somehow...

[E TwentyNine]

This one's beat up but sitting at zero bids at the moment with an opening bid of around $75 shipped.

http://www.ebay.com/itm/281321368009

Also has no cable, which might not be an issue if you're going to replace the controller anyway...

[Muirium]

Get it, Daemon, before I surprise my American brother with a huge, heavy box!

[mr_a500]

The peeling paint is no big deal (looks better without paint anyway) and the dirt on the keys cleans up easily, but I'd be worried about the conditions that thing has been sitting in. The space bar stabilizer is rusted, which means it has been in a damp environment.

[Daemon Raccoon]

Get it, Daemon, before I surprise my American brother with a huge, heavy box!

The problem is I have no money to buy a Beamspring.

[Muirium]

Me neither, realistically speaking. Bearing in mind I'd have to get that magnificent (if indeed rusty) beast back over here at some point. Caps are one thing, DisplayWriter keyboards quite an other.

[wheybags]

I reaaaaaly want to bid on this, but the seller isn't offering non-us shipping, and they seem to have set it so you can't ask questions
Any chance someone in the us could proxy for me? (I would love you forever)

[xwhatsit]

When I click on the `Shipping and payments tab' I see `The seller has not specified a shipping method to New Zealand. Contact the seller and request shipping to your location.' The `Contact the seller' words are a link where you can go through the usual process.

The spacebar stabiliser might be rusty but I'd still hold out some hope. The stabs on both my boards (one treated nicely, one neglected in a shed) both have surface corrosion. The actual guts of the beamsprings appear to have a great deal of surface treatment on the other hand (see the swirly `gold' treatment on the top and bottom halves of the steel sandwich holding the keys, and the slight blue/purple of the keystems).

At that price it's almost worth the risk.

Be prepared to pay approximately the same amount again for overseas shipping!

[wheybags]

When I actually get to the point where you're about to see a text box, it just gives me: "We're sorry but we couldn't find an answer for you. Unfortunately, this seller is unable to respond to your question. We suggest reviewing the item again to see if your answer is in the seller's listing."

[xwhatsit]

Bizarre!

Worst thing about eBay is geographically-impaired Americans

[Muirium]

You could try contacting the seller (click on their name, and you'll find it on the subsequent page). Sometimes they can be talked into opening up other regions of the world on their listing while it's live.

That or good luck finding a proxy.

Xwhatsit: how ever did you find any beam springs in New Zealand? Imported them yourself, I imagine?

[xwhatsit]

Yep—shipping was painful!

I think at the University of Auckland in the CS department they have (had?) a kind of display of early IBM gear that was used by said department long ago. Unfortunately when I was a student there I didn't know what a beamspring was so can't remember exactly what it was. Besides, I don't think they'd accept an offer of `fifty bucks for the keyboard bro!'

[wheybags]

There's a vt100 under the stairs in my uni and I wanna steal it so bad ;_;

[nourathar]

You could try contacting the seller (click on their name, and you'll find it on the subsequent page). Sometimes they can be talked into opening up other regions of the world on their listing while it's live.

But I think wheybags encountered one of these cases in which you can not even contact the seller if you are outside of their area. I've come across these a couple of times and that is very frustrating; my experience is that most sellers can be talked into shipping internationally, sometimes you need to take them through the ebay pages with instructions for sellers, though

But yeah, if you can't talk to them nothing will work. I do wonder how difficult it is to set up an ebay account in another country though: often I change ebay.nl into ebay.com to be able to see more keyboards, so it might be something as silly as that..

[Muirium]

Depending on other people's bids, I am very likely to take a shot at that board, since I can ship it to a US address. Of course, I am tremendously short of ammunition so I expect to be unsuccessful, but it's a nice little dream…

[wheybags]

I am going to bid anyway, have contacted the seller through his page but no response, will use a commercial shipping thing if needs be ;_;

[Muirium]

Okay, give me a heads up before you do. I don't want to get in your way… or to let this slip!

[wheybags]

I was gonna try snipe it ;_;
Is that a shitty thing to do?

[Muirium]

Well, it is if both of us do!

I only ever bid in the last minute, too. Standard ebay practice. I'll gladly let you have it if you're sure you're going for it. If in doubt, PM me a few minutes before the finish.

[wheybags]

I'm sure I'm gonna bid yeah (got JBidwatcher running already )
Thanks for not fighting and raising the price for whichever of us wins (that's what happened last time I bid on a beamspring ;_;)

[Game Theory]

So did anyone here get it? Just wondering.

[Muirium]

Not me, or Wheybags. Ho hum.

[wheybags]

My sniper program decided to just die at the last minute instead of placing the bid ;_;
never trust jbidwatcher!

[dorkvader]

So did anyone here get it? Just wondering.

someone bid a few hours before it closed, so I put in a bid as well just for kicks. AFAIK, there were at least 1-2 other people not in this topic who SAID they were going to snipe it.

Imagine my surprise when I won.

Anyway, I live about 2 hours from this guy, and am going out to the same city this weekend anyway to drop my roommate off. I'll be doing local pickup if at all possible.

[Muirium]

Congrats! Glad to hear it went to a good home after all. Now, we expect pictures of all the gory details of its restoration, of course…

[wheybags]

dorkvader, i jelly ;_;
(I had jbidwatcher set to go to $200, would I have beaten you? )

[Muirium]

Sure would have beat me!