(Keyboards in this article will also work with the OpenAC1.)
You probably know that the original Altair 8800 did not have a VGA monitor port and a USB keyboard input, as it appeared decades before that technology existed. You were expected to connect it to a serial terminal. My Pro kit includes a built-in VT100 Emulator to make it easier and fun to use, as most people will not have access to a serial terminal.
Unfortunately, you cannot simply connect any USB keyboard to it.
Why?
The PIC processor that runs the VT100 emulation is, of course, limited in its memory and processor speed. Also, the USB protocols can be complicated and memory intensive. For example, the USB keyboard protocol is different than the USB hub protocol, and there is not enough memory in the PIC to support both protocols (and the VT100 emulation).
So it was decided that the VT100 emulator would support only the standard USB keyboard protocol.
Well most "fancy" USB keyboards with multiple features, or wireless USB keyboards, actually have internal USB hubs which require the host computer to have separate USB protocols implemented.
So what USB keyboards will work with the VT100 emulation?
The easy answer is almost any standard, directly wired USB keyboard, with no additional features. Of course, a lot of people would prefer to pair their retro-looking Altair-Duino with a retro-looking mechanical keyboard. So I am assembling a list of verified working keyboards you may be interested in.
Verified Keyboards:
If you have run across any other mechanical/retro keyboard that work with the Altair-Duino, please email the link to me and I will share it.
Redragon K617 Fizz 60% Compact RGB Wired Mechanical Keyboard
Here's a nice, cheap mechanical keyboard with RGB lighting effects that has been tested and verified to work with the VT100 emulator. This is actually the keyboard I have on my bench to test my builds. Micro Center
Redragon K617 Fizz 60% Compact RGB Wired Mechanical Keyboard
A similar, more colorful version of the K617 is available on Amazon
Inland Rapture Mini 60% Gaming Keyboard
A cheap backlight mechanical keyboard that works fine with the emulator in the Altair-Duino. I picked one up for $30! (The pipe symbol is not recognized by the VT100 emulator.) Micro Center
iMICE 104 Keys Wired USB Backlit Gaming Keyboard
This keyboard is very inexpensive and has a nice retro/steampunk look. Walmart
onn Gaming Mechanical Keyboard
Here's a gaming keyboard with RGB lighting effects. Walmart
Sentry KX100 Gaming Keyboard
Here's a cheap backlit keyboard that is verified to work, but I can't link a single source. You can find it on eBay quite often, and Ricky Bryce found one at Dollar General for $15!
Inland iK100 USB 107-Key Keyboard
It's very simple, and cheap, and it mostly works with the VT100 (however the key with the backslash and pipe symbol is not recognized.) The good part is that it's only $4.99 regular price, and on sale regularly for $3.99 or less. Micro Center