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Another PS/2 Mouse ISA (ISA8) card adapter

Neat! Easy solution to an actual PS/2 interface requiring a fair bit of system integration, and the CPLD certainly makes for easier development/debugging.
 
Chuck(G) said:
Interesting, but since most ancient PCs already have serial ports, why not just do a PS/2->serial converter? You'd be rid of the FPGA.
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Or, just spitballing, why not a USB->Serial converter? There are a lot of inexpensive microcontrollers with USB host capability out there, you could probably do it with very little external circuitry. PS/2 mice are actually starting to get a little thin on the ground at this point.
 
I guess according to Amazon you can still buy a new one (PS/2, that is, not serial). Perhaps I'm projecting because the last time I needed one it turned out I'd been far too efficient at purging "old but not old enough to be interesting" from my personal stash. Mistakes we all make in the name of not turning into a *severe* hoarder.
 
Chuck(G) said:
For that matter, I still have a bunch of serial mice, including a serial trackball.
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Ditto...

I've got a TrueDOX Trackball with manual and software.
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Stone said:
While that may be the case in Outer Mongolia it certainly isn't in my neck of the woods.
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Quite the opposite... in the modern world, PS/2 slowly disappears.

But I don't see the point either - any USB host capable microcontroller should be able to provide both serial mouse and AT/XT keyboard data. There is no need to block an ISA slot and inherit compatibility issues (COM3, COM4 and interrupt sharing) on the way. If it would pretend to be a bus mouse interface, on the other hand...
 
Stone said:
How could you possibly know what the local situation is here? :)
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I did not talk about your local situation, but about the modern world. :)

Here in Sweden, it is getting harder to find new PS/2 stuff, since everything turned to USB years ago. It can be found easily enough in second-hand stores, in different need of cleaning and/or repair. Adapters don't always cut it since many manifacturers dropped PS/2 compatibility as well. It is not yet a problem, but it becomes apparent that it will be.
 
Svenska said:
Here in Sweden, it is getting harder to find new PS/2 stuff, since everything turned to USB years ago. It can be found easily enough in second-hand stores, in different need of cleaning and/or repair. Adapters don't always cut it since many manifacturers dropped PS/2 compatibility as well. It is not yet a problem, but it becomes apparent that it will be.
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Heck, in the heart of Silicon Valley it's not that easy to run out and just buy a PS/2 mouse off the shelf if for some reason you find yourself in a lurch. Seems like all the formally reliable surplus sources are closing up shop, thrift stores hardly carry computer stuff anymore, and you're certainly not going to find one on the shelf at Best Buy.

The main point was that while converting PS/2 (keyboards/mice) to "X" format was the no-brainer choice a decade ago (the peripherals were still pretty widely available in stores, the protocol was easily bit-banged by inexpensive MCUs, etc.) it's probably at least worth considering adapting "USB to X" instead for new designs. Because USB is now the thing that *everyone* is going to have handy or can just run out and buy.
 
PS/2 stuff it's not uncommon but is slowly fading. My interest on this project is due to the fact that all my KVMs have PS/2 connectors. No problem with keyboards but I need two mouses (one serial and one PS/2) on my desk and this is really annoying
 
Did FTDI have, at one time, a reference design for a USB mouse host that output serial data? I'm struggling to remember.

At any rate, it's easy-peasy, even for an AVR to handle small USB devices MCUs like the ARM, usually have USB OTG built in.
 
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