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Atari 520ST + TI99/4A + T3100 + Unisonic 21

Posted: 11 Feb 2017, 20:39
by cumwagondeluxe
I made a post in the "How much is ___ worth?" thread about this stuff and ohaimark requested photos with pulled caps so I figured I might as well post a mini review of everything. Currently only have photos of the 520ST with caps pulled because it was the only one I felt OK to pry the caps off with a knife and potentially ruin a switch due to how shitty it felt, but I'll put up the rest tomorrow night when I have access to one of my keycap pullers.

Album: http://imgur.com/a/1FhUH

Unisonic 21 "Jimmy the Greek" Calculator/Blackjack thing: Don't have a screwdriver small enough to open it handy, unfortunately keyfeel wise the travel is short as hell and fairly mushy though it definitely is using a spring/something metallic. Found an old news article (http://www.si.com/vault/1977/11/28/6237 ... t-plays-21) about it, which if correct means this thing would've cost about $250 in today's dollars - pretty overpriced given that this thing really feels like some childrens toy in terms of build quality/weight.

Atari 520ST Keyboard: I'm assuming these are some sort of foam and foil given how similar it looks to those Amiga boards with foam and foil switches. Feels like absolute dog shit - very mushy, short travel, and return force sucks too. I'm not really sure why these have the external springs - I removed the one in the picture and put the cap back on to see what would happen and it honestly helped the feel quite a bit. Still not much, if at all, better than a cheap dome over membrane keyboard but it at least feels usable without the spring.

Toshiba T3100: The T3100 is great - definitely gonna hunt down some more SKFL boards in the future, especially if I can find more with caps this nice. Somewhat unique switch in terms of sound, though feel wise it's just a nice smooth linear. I'd prefer something a little heavier, but I still find these fun to type on just because of the sound they make.

Texas Instruments TI99/4A: The lot also included a Made in USA TI99/4a which has the General Instruments SKCC alps clones - really nice linear switch, super pingy though. Even just running my fingers across the keycaps (not pressing down or anything really) can produce an audible ping which I personally don't mind. Caps are really nice Clare-Pendar ones, though they aren't compatible with any other switches from what I've read online.

Posted: 12 Feb 2017, 01:05
by Daniel Beardsmore
Atari 520ST Keyboard — this seems to be [wiki]Silitek dome with slider[/wiki], which is a rubber dome keyboard. (The detailed pictures aren't on the wiki — it was described and depicted at KBtalKing, which has since disintegrated.)

Posted: 12 Feb 2017, 07:27
by cumwagondeluxe
Daniel Beardsmore wrote: Atari 520ST Keyboard — this seems to be [wiki]Silitek dome with slider[/wiki], which is a rubber dome keyboard. (The detailed pictures aren't on the wiki — it was described and depicted at KBtalKing, which
has since disintegrated.)
More pics: http://imgur.com/a/rIOV2

I think the TI99 is using Alps and not the GI clones - I assumed because the PC/outer shell had made in USA on it, that I had one with GI clone switches but the PCB would seem to indicate that they're in fact Alps. Pretty happy with this one, definitely going to look for a nice condition M0110 after this.

Sounds like you're spot on with the 520ST also - I found a small screwdriver hiding in the basement and unscrewed a portion of the PCB (This thing has like 30 screws on it :/) and lo and behold each slider's got a little transparent black rubberdome under it with what I'm assuming is some conductive material in the center of the dome that presses onto the PCB. A portion of the back side of the PCB is also covered with a clear flexible piece of plastic glued on with some nasty sticky adhesive - I'm guessing when assembled it's probably there to protect the PCB from getting shorted by something in the case. Will confirm if caps are MX compatible tomorrow, but this keyboard is seriously awful. Pretty much unusable in its default state, and no better than the usual shitty office membrane keyboard with the external springs removed. Also, I'm assuming B.I. on the PCB is the manufacturer or something -- all the other writing was for LEDs/diodes/etc.

Some pics of the opened calculator bits included too. Keycaps are cool, might save those or ship them out for people if they pay shipping and want to make keychains out of them or something. Very thick doubleshot ABS it seems, with the larger keys having a different stem (big cross vs. circular) although nothing actually goes in them. The black thing is a small rubberdome basically that just sits on the outside of the stem area point facing down, and the "switch" works using a spring that goes in the stem/over the rubberdome. It sits on top of a piece of plastic with a contact leaf on the other side and a hole for each key, and then when you push down on the key the little rubber cone pokes out through the hole and pushes a small piece of the contact leaf onto the PCB.

Posted: 12 Feb 2017, 07:45
by Findecanor
cumwagondeluxe wrote: Will confirm if caps are MX compatible tomorrow, [...]
The cruciform in the Atari ST are slightly larger than Cherry. At least, they were on my Atari STe.
The keycaps are nice doubleshot but the surface is wider than the norm.

Posted: 12 Feb 2017, 14:18
by Daniel Beardsmore
Looking at the pictures, I'm guessing that the Atari keyboard PCB does not have any recognisable markings? I was hoping it would say "SK" something, but it may not:

http://article.cool3c.com/bookmark/info ... %99/391784

That's the KBtalKing article for the keyboard I was thinking of. Those aren't the original images — I don't know what's happened here. This is the original article, but none of the images load:

https://www.cool3c.com/article/6180

The images are still there on Photobucket though. I'm going to see if I can get at them and archive them while there's still anything left of KBtalKing to even find in Google Images.

Posted: 13 Feb 2017, 06:59
by cumwagondeluxe
Findecanor wrote:
cumwagondeluxe wrote: Will confirm if caps are MX compatible tomorrow, [...]
The cruciform in the Atari ST are slightly larger than Cherry. At least, they were on my Atari STe.
The keycaps are nice doubleshot but the surface is wider than the norm.
Yeah, can confirm the stems are too large for Cherry MX. Kinda unfortunate, but whatever - pretty satisfied with SKCC TI99/4A and the T3100 board for $60.

Posted: 13 Feb 2017, 09:40
by Daniel Beardsmore
Curious. I assume that switch manufacturers adopted Cherry and Alps keycap mounts so that they could be used with off-the-shelf keycaps (especially those from Tai-Hao). So if these switches are specifically not Cherry MX mount, then I have to wonder whose keycaps they were meant for instead.