deskthority

There are no date stamps on this keyboard but it is an NEC APC-H25 keyboard that accompanied the NEC Advanced Personal Computer released in 1982.
The switches appear to be primarily NEC vintage linear (just basing this on blue stem color) as well as SMK J-M0404 series.


On this particular board, the stems on the brown stemmed SMK switches were particularly fragile and two snapped in half with only mild force while pulling key caps - no problems with the blue or black stemmed switches. Since I had to desolder the switches that broke to repair them, I took some additional pics of them:
The switches on this board are quite smooth and I like them quite a bit - they feel considerable nicer that the vintage SMK switches on the Kaypro 4 board I have - maybe a difference between the NEC and SMK switches - or maybe the switches on this board are just cleaner and in better overall shape.


I went ahead and wired it up to the Teensy++ and am using the board to type this.
Quick video of typing on the board: Overall I was pleasantly surprised by how nice the switches on this board feel, and I do like the clack!

SMK's part colours are confusing. A cream or beige base in J-M0404 series has thus far denoted low force, so the switches with a beige base should all feel lighter. Thus far, all beige/cream-base switches have also been low-friction (lubricated) with the corresponding cream body and brown slider. That switch you took apart seems to be lacking its lubricant though; there should be a thick blue-white substance on each side of the slider.

It's impossible to tell from the photos which keys have which switches, and whether the switch types suggested by the colours would make sense. Where for example a Cherry or Alps keyboard typically has the same switch for each key, SMK keyboards can show a surprising amount of variation, and I've never had such a keyboard to try out, to see if it feels better for it.

Since these switches seem to use standard SMK colours, the suggestion is that the blue slider has a meaning other than decoration, such as a different weighting. That is, the NEC version wasn't blue because it was NEC, but because they were using a different specification (like green vs cream Alps SKCC).

Also, I notice a switch with ribs in the retention clips, which is a new discovery.

Curiously, the NEC-branded switches were found in a PCB made by SMK, while you have SMK-branded switches in a PCB made by NEC.

I saw one of these on eBay recently. A very elegant-looking keyboard, great job at getting it working .

Chyros wrote: I saw one of these on eBay recently. A very elegant-looking keyboard, great job at getting it working .

Thanks! I think there is still currently one on eBay, but the price is a little steep.

Daniel Beardsmore wrote: It's impossible to tell from the photos which keys have which switches, and whether the switch types suggested by the colours would make sense. Where for example a Cherry or Alps keyboard typically has the same switch for each key, SMK keyboards can show a surprising amount of variation, and I've never had such a keyboard to try out, to see if it feels better for it.

All the single unit keys use the blue sliders, except for the Caps Lock which uses a black latching switch. The remaining keys use the brown slider switches except for GRPH1, GRPH2 and ALT which also use the black latching switch. I don't really detect any significant difference between the blue and brown stemmed switches, but maybe that's just me.

Very nice. I almost bought one of these some time ago.

Nice indeed!