In search of 4B3A Microswitch Keyswitches (for a system restoration, not keyboarding)
bhilpert at shaw.ca
Thu Jul 9 23:58:31 CDT 2020
On 2020-Jul-09, at 9:39 PM, Ian Finder via cctalk wrote:
> I know what you guys are thinking- no, this isn't for a keyboard collection
> or some modern build or some other nonsense like that.
> I have a friend who is restoring a fairly interesting and historically
> significant vintage computer-
> The correct SD-series replacement switch would be the 4B3A-
> *** These can allegedly be found on some of the Diablo printing
> Subject to what /appears/ to be a batch-related encapsulation failure in
> the glue on the proprietary hall effect sensors, around a little over half
> of the switches on the current keyboard are bad.
> It is possible other switches ending in ***A could be made to work with a
> bit of labor and disassembly (swapping the fairly brittle sensors).
> I am not a keyboard expert but I have learned that you can remove a key on
> some of these microswitch keyboards and read the model fairly easily on
> each switch.
> Please let me know if you have a lead on a donor for these switches. They
> will be put to good use, and you can reply to me off-list for more details.
Are these the key-switch model which snap into a thin-gauge springy stainless-steel U-channel to form the rows of the keyboard?
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