deskthority

Used this through most of the 90s:





Not my pictures. Thought long gone, but today found one old unit, to my surprise. Keycaps are MX compatible, and the profile seems SP DCS at first glance. Pad printed.

Initially thought slider over rubber dome, but there is actually a single-sided PCB, a handful of diodes (not as many as keys, though) ... and some disassembly ahead.

Right, slider over rubber dome with graphite center, shorting PCB pads.
i8049 for the brains. The usual for that time AT/XT switch.
A different colored dome for the spacebar. Silicone grease still present on the spacebar stabs.
Somebody resoldered few diodes, quite unskillfully. The copper side of the PCB looks fine for the age.

I should finally get some lens ..

Diodes? You lucky SOB. I had the BTC equivalent: PCB but no diodes (made in 1993 or 1994). I encountered ghosting long before I had any idea what was going on.

This one is around 1992. Weird number of diodes - about 18-19 of them.
I am laughing more at the MX compatible sliders. No wonder the first SP DCS keycap set I got looked strangely soothing to me.

Maybe I will clean this beast a little. Any good way to clean the domes and the graphite spot on them?

As a side note, some dust bunnies have made their way to the copper (contact) side of the PCB. Despite handful of screws clamping the barrel plate to it. All graphite spots seem okay (not worn out), so any key problems might have been mostly from dirt. Not that this matters anymore.

woody wrote: I am laughing more at the MX compatible sliders.

Why, what's so funny about them?

Just my nostalgia, and why I feel so at home with DCS and thin SP keycaps. Owning real MX, or any other kind of microswitch board, here in the 90s was prohibitively expensive.
I also paid more for my Silitek for not having Cyrillic legends.

derp

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