So I've largely completed my PS2-//e interface and since the 3600PRO uses odd voltages for the keyboard scan I decided to replace it.
I did this by removing the 3600PRO and connecting my microcontroller to the IC socket as well as making a few other connections to the keyboard connector. The code works fine, and I am able to type and reset and use the "Apple keys" with no issue, but this got me thinking.
I was warned of counterfeits on the market, and that coupled with it no longer being made, makes me wonder if a plugin replacement is something the community needs? I assume the PS2 adapter isn't so interesting, but I could easily add the row and column scanning to my code and make a substitute for this encoder.
The question is, is there any need for it - or is it an answer to a question no one asked?
PS/2 keyboards are starting to get scarce, hence there not being a huge demand for that any more. USB keyboard support would make it a desirable product I'd think. There are already a couple of USB keyboard solutions for the //e, but most of those I've seen plug into the keyboard connector and require the nromal 3600-PRO circuit to be working. I'd think there would be room for a solution that plugged in there.
Gamers will keep them alive I think. I personally prefer them because on my PC I can set BIOS to recognize ctrl-esc as a power on signal .Which means I no longer need to keep the tower in an accessible location. Can't remember the last time I needed to put a CD/DVD rom in and of course floppies are no more (I don't think windows 10 even supports them anymore)
Anywho... USB could be a thing. I wanted ps2 because of my preference for them but it's an idea.
Do mobos even have PS/2 connectors anymore? I haven't had one that did in at least like 10 years. Admittedly I'm not a big gamer. I mostly use Logitech wireless USB kyb/mouse combo these days.
So called gaming mobos almost always have them - mostly for n key rollover even tho few ps2 keyboards actually implement the diode isolation required for true n key rollover. I suppose its mostly marketing but they natter on about n key roll over and latency and so on. Many gaming keyboards either auto switch or can be manually set to usb or ps/2 even tho they only have a usb connector, manufacturers supply a pin to pin adapter to get it connected .
I'm also playing with the replacement of original keyboard by PS/2 I also introduce a connector to plug a bluetooth module...
my idea is to create a small box (arduino size) to which I would connect a USB keyboard and send USB scancode converted to PS/2 through bluetooth serial
Actually I have prototype of board for 7 or 8 machines (not yet the Apple IIe) [Apple II / several Commodore / Tandy Coco / Oric / PC XT]
when the first batch works I'll make a board for the Apple IIe too...
I've been considering a similar project, but I want to scan the //e keyboard with the microcontroller, then simultaneously emulate the 3600-PRO through its socket and send the usual PC-style keyboard data out over the USB port.
I think I'll have to add blocking diodes to every key for it to work right, though. Oof.
How timing-critical did your implementation end up being? I was going to try to use a 12 MHz 8-bit Teensy++ 2.0 that I happen to have lying around, but I am worried that it may not be fast enough, if the clocking is critical.
The 3600 scans with a clock around 50kc. Aside from that everything is "on demand" the 3600 puts out a 20us pluse saying " I got data" to the system while simultaneously setting the address bits to the keyboard ROM (which remain that way until a new key is pressed, even when the 1st key is released the address bits remain set). Later the system polls the ROM for the keycode .
No real timing issues to speak of really (nano has a 16mhz clock)
Cool, sounds like what I've got will work then. Thanks! :D