[coreboot] v3 parallel port console?

Joseph Smith joe at settoplinux.org
Tue Sep 16 21:10:21 CEST 2008

On Tue, 16 Sep 2008 20:17:36 +0200, Peter Stuge <peter at stuge.se> wrote:
> Joseph Smith wrote:
>> > Joe, I remember you were interested in crazy hardware hacks.
>> > Would designing a floppy->parallel port interface (or
>> > floppy->serial) fit your bill?
>> That would be a crazy hardware hack. I don't think it would be too
>> dificult considering floppies are basicly serial devices. I'll do
>> some research.
> These are the signals:
> http://hardwarebook.info/Internal_Diskdrive
>> I think the hardest part would be a driver/software able to
>> manipulate the floppy port for serial.
> Not so hard, it will just be bit-banging the signals. I would suggest
> using 8 output signals, one strobe out and one ack in to increase the
> transfer rate.
> The drawbacks are that timing and thus transfer speed will differ
> with CPU speed and that it is relatively impractical to drive
> communication like this.
> I'd like to also nominate PS/2 for consideration, it already comes
> with a serial transceiver (odd-8-1) and once the superio is
> configured, writing one byte should need just a few io instructions.
> http://hardwarebook.info/Keyboard_%286_PC%2C_PS/2%29
> http://hardwarebook.info/AT_Keyboard/Mouse_protocol
> and the PORTS file from
> http://www.cs.cmu.edu/~ralf/files.html (search for K-P0060)
> 10-16.7 kHz it's kind of slow, but..
My vote is for PS/2 also. There's a data and a clk line, so simple. The
question is, newer motherboards are not coming with PS/2 ports, only USB
(especially BTX). So Carl-Daniel how many of those boards have PS/2? Here
is my favorite site to find out what devices have what signals (and pin
outs): http://pinouts.ru/

Joseph Smith

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