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geekhack Community => Keyboards => Topic started by: False_Dmitry_II on Thu, 24 March 2011, 03:35:10

Title: Of Model M's and SDL cables
Post by: False_Dmitry_II on Thu, 24 March 2011, 03:35:10
I read somewhere (I forgot where) that every controller that feeds to a computer through an SDL cable is capable of communicating to all possible other ends of SDL cables. The implications being that if you had a Model M with a SDL plug and the current cable in said plug had a phone plug on the other end, you could toss this cable and plug in one with AT or PS/2 and simply use it. How horribly wrong is that?
Title: Of Model M's and SDL cables
Post by: ch_123 on Thu, 24 March 2011, 05:16:00
There are only AT and PS/2 SDL cables for IBM keyboards.
Title: Of Model M's and SDL cables
Post by: trievalot on Thu, 24 March 2011, 05:38:43
You may be thinking if terminal boards with rj connectors
They need a controller swap, and won't work out the box. Think at vs xt
Title: Of Model M's and SDL cables
Post by: ch_123 on Thu, 24 March 2011, 09:32:52
Any of the RJ or 240-degree DIN connector keyboards will always have permanently attached cables.
Title: Of Model M's and SDL cables
Post by: False_Dmitry_II on Thu, 24 March 2011, 11:41:50
In that case whatever it is I read is stupid because as far as the controller is concerned AT and PS/2 are the same.
Title: Of Model M's and SDL cables
Post by: ch_123 on Thu, 24 March 2011, 16:22:03
I often wonder why IBM ever bothered with detachable cables on the PC Model Ms. Traditionally, IBM sold the 1390131 with ATs, and the 1391401 with PS/2s, so it wasn't if they intended the same keyboards to be used interchangeably with either their PS/2 or AT computers. When Lexmark took over, they started churning out ones for the retail market, they made fixed cable ones, and bundled a PS/2-AT adapter, which is a much cheaper and more elegant solution. The only advantage I can think of that the cable uniquely offers is the ability to have different lengths of cable.
Title: Of Model M's and SDL cables
Post by: False_Dmitry_II on Thu, 24 March 2011, 18:46:06
Well there's also that if you were to end up destroying a cable all you have to do is toss that cable and use a different one. Much easier than breaking out the solder or replacing the keyboard.
Title: Of Model M's and SDL cables
Post by: ch_123 on Thu, 24 March 2011, 19:31:44
Quote from: False_Dmitry_II;318006
Well there's also that if you were to end up destroying a cable all you have to do is toss that cable and use a different one. Much easier than breaking out the solder or replacing the keyboard.


If that was IBM's consideration, detachable cables would have appeared on the overengineered beam spring and Model F keyboards. It could have been an improvement they made, but I'm not sure really.
Title: Of Model M's and SDL cables
Post by: False_Dmitry_II on Thu, 24 March 2011, 21:40:53
Why do you say that kishy? I saw your mod to some terminal boards, but I was pretty sure those didn't have phone plug style cords, I thought they were something else.

But yeah, I've seen normal model m shaped keyboards on ebay with the phone plug type cord, so I don't know if those would be called terminal or not.
Title: Of Model M's and SDL cables
Post by: False_Dmitry_II on Fri, 25 March 2011, 03:47:04
Nah, I just keep seeing them show up (looking like both terminal boards like the 1397000 and like any normal model m) on ebay with like $5 starting bid auctions and no bites because its kind of a pain to get working. It just seems like a terrible waste that there are that many BS keyboards that would be fine otherwise (and cheaply if there were an easier fix). Course it also seems like there isn't much of a shortage on PS/2 compatible ones either, so I guess it isn't too big a loss.