IBM AT ANSI Mod -- Are XT and AT Rocker-Springs Identical?

[Hypersphere]

I will soon be getting an IBM AT keyboard, and I would like to do an ANSI mod, which I understand involves simply moving some rocker-spring (hammer-spring) assemblies to different barrels. However, I have some other modifications in mind that will involve adding some additional rocker-spring assemblies. Unfortunately, although I have some extra XT rocker-springs, I do not have any extras from an AT. Therefore, my main question at this point is, are AT and XT rocker-spring assemblies identical, or will I need to get some AT rocker-springs? Thanks.

[JBert]

I can't remember if they're 100% identical, but I believe they are very similar.

What you need to be most aware of is the difference in barrels - one of them has an extra "pin" protruding through the front plate while the other has a lip connected to the barrel.

[Muirium]

Interesting… have you got some pictures? I wonder which one the Kishsaver is more like.

[JBert]

Compare the barrels of the PC portable:



with the barrels of a later model F 122:



See linked threads for the source of the images.

[Halvar]

I dont have a Model F, but it seems to me that the springs are different, see this post on GH:

http://geekhack.org/index.php?topic=578 ... msg1318050

[Muirium]

I was just replacing a couple of springs in my Kishsaver the other day, and this picture Halvar linked is indeed accurate:



Good news for me: a Model M spring works on a Model F flip plate! I just chopsticked it right on in. The only difference I can tell from other keys is in the pitch of the twang. Nothing horrible.

[JBert]

I dont have a Model F, but it seems to me that the springs are different, see this post on GH:

http://geekhack.org/index.php?topic=578 ... msg1318050

That's model F vs model M.

What rjrich asked was if the springs between model F XT and AT got changed, which I can't really prove.

[Hypersphere]

Thanks for the replies. Although I would like to get the extra springs and hammers that I might need before tearing down the boards for refurbishing/modding, I hope to have the AT by next week. As soon as I can find the time, I will tear down both an XT and the AT to see what differences, if any exist, between the spring-hammer assemblies of each.

[Parak]

Barrels are not compatible (but can be made to if you don't mind some extra wobble), and the spring/flippy are compatible. There were a few different flippy designs for capsense buckling spring boards with minor differences (unknown as to why), but they are all interchangeable.

[Hypersphere]

What about compatibility between XT and F-122 barrels and rocker-spring assemblies?

I now have several XTs, some of which could serve as donors. I have two F-122s, which I am interested in restoring and modifying -- hoping I can use parts from XTs for the F-122 restorations/modifications. Of course, I can answer my own question soon, but I have not yet opened up the F-122s.

Thanks.