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PC serial/PS2 mouse to CD-i adapter

Posted: Tue Sep 06, 2005 8:06 pm
by MoSPDude
Has anyone been interested in building the PC serial mouse to CD-i adapter? Is there more interest in a P/S2 mouse to CD-i adapter?

Just wondered if anyone was thinking about building it.

Craig

Posted: Tue Sep 06, 2005 11:27 pm
by cdifan
Let me just plug that CD-i nullmodem cable that Devin's selling again:

With it you could use any PC input device (mouse, joystick, keyboard, whatever) with your CD-i player. Even things like action replay are possible.

It's just a matter of the appriopriate PC software; all the protocols are publicly documented. Not very hard either, I think...

Using your PC as a CD-i modem would be a little harder, but still very doable...

PS. I have no financial interest in those cables, just like to see them used!

Posted: Wed Sep 07, 2005 2:49 am
by MoSPDude
I had a go at that with a nullmodem cable I made up myself, but couldn't get windows to respond in time to the RTS toggle and as such the CD-i ignored it. I wrote a nice windows program to capture the mouse and send data too before I tried it properly, expecting it to work easily but I gave up after a few hours. I might have another go it.

Damned windows and windows XP, I imagine a proper pure DOS app would be able to do it.

Craig

Posted: Wed Sep 07, 2005 7:25 am
by cdifan
Craig, you're the adaptor guy, right?

I agree, the quick RTS response is probably the hardest part. It's supposed to be within 10 ms...

Couldn't you try to (ab)use the flow control stuff? Detect RTS being negated; kill all output and turn on flow control and then queue the ID byte, so that Windows will immediately send it *from the drivers* when RTS is asserted, meaning that your application doesn't have to be scheduled for this to happen...

I'd assume that the usual RTS-negative time, while specified as 10ms minimum, is in practice much longer?

Also, most pointing device ports are supposed to autodetect a device being connected. Maybe this could be triggered in some way, to re-invoke the ID recognition?

As the last resort, you'd have to write a serial widget or COM port driver. This page has some info on the former; isn't there there a sample COM port driver in the Windows DDK? Just my thoughts...

Posted: Wed Sep 07, 2005 8:30 pm
by MoSPDude
Writing a COM driver I think is going overkill, though I do have the WinDDK lying around somewhere.
Perhaps queue the ID byte is a way forward with it.
As for timing of the RTS being negated, while writing PIC code for the adapter - the CD-i seemed to hold it for longer if its struggling with the mouse data ie bad baud rate in initial case with dodgy crystal!

Posted: Sun Sep 11, 2005 11:40 pm
by MoSPDude
Just as an add-on, if anyone does build either the PS/2 and serial mouse converter or serial mouse adapter to CD-i - please post details of success or failure here, just so I can have an idea of any problems or if I've drawn something wrong.

Thanks,
Craig