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geekhack Marketplace => Great Finds => Topic started by: ander on Mon, 30 January 2017, 17:33:02

Title: [ENDED] Two Micro Switch 99SD24-3's (Honeywell Hall Effect)
Post by: ander on Mon, 30 January 2017, 17:33:02

"These switches are among the highest quality ever produced by any keyboard switch company, with reliability being paramount to their design... The Honeywell Hall Effect switch is most famous on some Symbolics keyboards, as well as the Space-cadet keyboard." (From Desthority's Micro Switch SD Series page (https://deskthority.net/wiki/Micro_Switch_SD_Series))

MICRO SWITCH 99SD24-3 SD-16234 F14 Key Board 1985 USA S/n A0703 (http://www.ebay.com/itm/MICRO-SWITCH-99SD24-3-SD-16234-F14-Key-Board-1985-USA-S-n-A0703-/222369051820)

MICRO SWITCH 99SD24-3 SD-16234 F14 Key Board 1985 USA S/n A0691 Date Code 8530 (http://www.ebay.com/itm/MICRO-SWITCH-99SD24-3-SD-16234-F14-Key-Board-1985-USA-S-n-A0691-Date-Code-8530-/222369067323)

Same seller; $75 + 26.20 shipping for each


(http://i.ebayimg.com/images/g/W6YAAOSwnHZYbxT7/s-l1600.jpg)


(http://i.ebayimg.com/images/g/K98AAOSw2xRYbxUY/s-l1600.jpg)


(http://i.ebayimg.com/images/g/VN0AAOSwEzxYbxrp/s-l1600.jpg)


(The front images of both boards are identical.)

Some of these sold for around $100 + shipping (https://geekhack.org/index.php?topic=81007.0) last year.

Title: Re: Two Micro Switch 99SD24-3's (Honeywell Hall Effect)
Post by: ander on Mon, 30 January 2017, 17:41:02

For some historical perspective, here's a cool piece (https://www.linkedin.com/pulse/post-dcs-era-timothy-triplett) about some of the early Honeywell Distributed Control System (https://en.wikipedia.org/wiki/Distributed_control_system) consoles, for which boards similar to these were developed.

Title: Re: [ENDED] Two Micro Switch 99SD24-3's (Honeywell Hall Effect)
Post by: piero.a on Thu, 23 March 2017, 02:22:23

Did you know where I can find an Honeywell keyboard with 1A3S switches? I need to repair a TI990/1  :(