From: Jim Brain (brain_at_jbrain.com)
Date: 2004-10-23 03:37:14
Scott McDonnell wrote: >Ok. Sounds like you got it working satisfactorily. : ) Just thought I would >pipe in and offer my own suggestions. Hope I was at least some help. > > Well, between you and Hársfalvi, I learned quite a bit more about analog. I just never did grok the analog stuff we did for my EE degree. Digital I completely understand, but the class on transistors (Q and all that) just didn't mesh, and the Fourier analysis class I barely kept my head above water in. I really should grab my old texts and learn this stuff, as Fourier seems very useful, and knowing how the non-digital aspects on transistors would be applicable, but I've got so many cool projects to finish, so your emails may have to suffice for a while. The main problem now is how to create a RAW data transfer mode using the joystick port. Not many bits to work with, and the keyscanner routines wreak havoc with a direct approach. No one has responded on that issue, so I am assuming there is either no interest or no better ideas. What I've come up with is: if no buttons are pushed on controller, put controllder lines in HiZ mode, and watch them. If a 10101 shows up, watch for 01010 for X uS if 01010 shows up, watch for 10101 for X uS Once that occurs, watch Fire line (now clock) for H-L transition read command nybble. (0000 or 1111 is go back to normal mode, in case keyscanner kicks in) 0001 is read raw data when clock goes H, load length (length of packet *2 + 1) wait for L-H transition load controller type (serial mouse, ame controller, etc.) wait for L-H transition send packet go back to wait for command mode. At all times, POT lines send valid data. Jim -- Jim Brain, Brain Innovations email@example.com http://www.jbrain.com Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times! Message was sent through the cbm-hackers mailing list
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