Much has been written here on OLPC News concerning any and all technical aspects of the XO computer. I am Benjamin Nead, an itinerant tinkerer in the broadcasting industry, and I tend to think that just about anybody that takes a critical look at this remarkable machine from afar typically walks away quite impressed with what has been accomplished by the OLPC consortium.
That it has been developed "behind open doors" makes the entire engineering aspect project all the more impressive. Indeed, one can visit the official OLPC web site and study all the details of the XO that one could possibly ask for . . . except, curiously enough, for a rather important one: the size and polarity of the DC power input plug.
For the record, the official OLPC Hardware Specifications web page has basic electronic criteria, but there's almost nothing in regards to the mechanical aspect of the connector itself
"Power: 2-pin DC -input, 10 to 20 V usable, -50 to 39 V safe, one- time fuse for excessive input"If one were to visit a typical electronic supply store (which may or may not be conveniently located in one of the various third world countries where the XO will be showing up) and ask for a "2-pin DC -input" connector - or any DC connector, for that matter - the first words from the salesperson behind the counter will be "Which one?", as there is a rather large variety to choose from.
Also, the term "2-pin" doesn't really describe the physically appearance of what OLPC and their collaborators have settled upon. Photos of production XO machines and the most famous matching accessory, the Potenco power generator, indicates that it's a single pin coaxial barrel connector of some sort that (obviously) has two electrical conductors, one negatively (-) charged and the other being positively (+) charged.
Regardless . . . even if you are able to obtain the proper unit, one then also has to determine which wire gets soldered to which pole on the connector. So, being naturally curious, I decided to find out. What harm is there in asking? My initial inquiry with OLPC was greeted with a cheery-toned form letter that referred me right back to very same tech page that I found to be so ambiguously worded.
I then wrote back pointing this out. After several days, no further communication from OLPC seemed to be forthcoming. I next turned my attention towards Potenco and asked the same questions. As with OLPC, they sent me a happily worded generic "thanks for your interest" email that contained no technical information whatsoever.
I emailed back and politely pressed a little harder for a real answer. The contact person there then cryptically advanced the following:
"I'm afraid that this is something you will need to discuss with OLPC directly. I'm sorry we can't help you more, but it's best that they have this conversation with you. Thanks for understanding."Well, that's odd. Who wears the pants there anyway and why can't they say which particular $2 Radio Shack part they're using without OLPC's expressed permission? I made mention of this curious correspondence here on OLPC News last week and someone suggested that they (both OLPC and Potenco) might have specified their own specially sized proprietary plug to scare off uninvited third party power supply developers.
I tended to doubt this, though, as it would significantly add to the cost of the machine, where low retail price points are a goal and there is a genuine stated desire to make the computers as field-serviceable as possible. Anyway . . . since I was subtly rebuffed (and I do, after all, have a life beyond enigmatically probing for details on a laptop that I can't even buy yet), I decided to not actively pursue it any further.
That is, until I got another email from OLPC early this past week that stated:
"The latest one I've seen is about 3.25 inches by 2 inches. The voltage and such will be different depending on the country"Well, I thought to myself, that a pretty damned big plug! And they're going to alter the voltage specifications for different geographic locations? It's obvious that this administrative staff person was confusing a power transformer for a connector, but at least they were kind enough to attempt some basic research and get back to me.
I wrote back (with a visual reference in the form of a hyperlink showing a photo of common connector types) in an attempt to finally get an answer. The reply that I received essentially said they appreciated my interest, but were to busy engineering to answer my question.
Now I was angry. So I fired back with a single sentence email that basically stated that a real engineer would know the difference between a plug and a transformer, signing it with a simple "Goodbye" and expecting that no further contact. But I was surprised, once again, to find a reply to my bitter snipe in my email inbox the next morning, basically restating the same thing that had been said by this same person the day before.
I thought it prudent to write back with a bit more of a controlled response this time. After apologizing for the coarse tone of my previous email, I stated the following in hopes that they would finally appreciate that there just might be a certain amount of importance in having this seemingly obscure statistic available to anyone who bothers to ask :
"The information I'm requesting is NOT presented on any of the OLPC pages. Please believe me when I tell you that I've have combed through all of them very carefully before I began my bothersome email correspondence.As of this past Friday, I have yet to receive a reply. It remains to be seen if I (or anyone who would really needs to know) will be able to extract this information from OLPC.
If I (technically adept, too much free time on my hands, etc.) cannot extract this information from the OLPC engineering and public relations oligarchy, then how is someone in one of these third world countries going to get through? What are you going to tell the poor kid in Nigeria who wants to hook up a car battery to his XO when he asks the exact same questions that I have been asking?
This is something that someone in a far more desperate situation than I will be asking of you some day. I would encourage your team to make the power input statistics publicly known at their earliest convenience.
Dual mode screens, state-of-the-art WiFi reception and a cutting edge Linux GUI aside, if you (OLPC) can't tell someone what size power input plug is being used and how it's polarized, then your precious computer becomes a useless plastic brick on an African prairie in no time flat."
The XO power plug saga continues.