On 16.09.2008 21:10, Joseph Smith wrote:
On Tue, 16 Sep 2008 20:17:36 +0200, Peter Stuge peter@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/
All of them have PS/2. However, some only have one PS/2 port which is either a pure keyboard or a combined keyboard/mouse connector. The latter may pose challenges regarding pinouts and/or electrical interfaces (multiplexing?).
Guys, have you noticed how similar this idea is to the often-derided USB flash key plugged into a USB<->PS/2 converter? That's a great thing! It means we'll attract all sorts of crazy hardware hackers.
Regards, Carl-Daniel