Info about socket interface

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David Schmenk 2013-05-31 17:24:50 -06:00
parent d3b943c369
commit 7cb7f1fdc7
1 changed files with 1 additions and 1 deletions

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@ -40,7 +40,7 @@ Reboot the Apple II with the newly created floppy in the start-up drive. If eve
Using a2pi: The Apple //c and //e keyboards are pretty minimal compared to modern keyboards, and the Apple II Mouse only has one button. In order to provide most of the funcitonality required of modern OSes, the Open-Apple and Closed-Apple keys are used as modifiers to enhance the keyboard and mouse. On the keyboard, Open-Apple acts just like the Alt key. The Closed-Apple key acts like a Fn key, changing the actual key codes. Currently, the Closed-Apple key will modify the number keys 1-0 as funciton keys F1-F10 and the arrow keys as Left-Arrow=Home, Right-Arrow=End, Up-Arrow=PgUp, Down-Arrow=PgDn. For the mouse, when you click the mouse button by itself, that is the left(default)-click. Open-Apple along with the mouse button will return the right-click, and Closed-Apple along with the mouse button will return the middle-click. If you should ever need to exit a2pi, press Closed-Apple ESC on the Apple II keyboard. This will exit both the code on the Apple II and the Raspberry Pi. This is useful when developing and debugging the drivers/daemons. a2pid can be run directly (not as a daemon) by leaving off the '--daemon' option. Enabling printf's in the code allows one to watch the packets arrive and get processed when run from a network ssh session.
Theory of operation: Apple II Pi works by running code on the Apple II and the Raspberry Pi, talking to each other with a simple protocol. The Apple II basically appears to the Raspberry Pi as an external peripheral, not unlike a USB keyboard and mouse. The Apple II floppy boots into ProDOS and runs a simple machine language program that scans the keyboard, and mouse if present, sending the events out the serial port to the Raspberry Pi. It is a very simple protocol and the serial port is running at 115.2K baud, so it is fast and low overhead. On the Raspberry Pi, a little daemon runs, waiting for packets on the serial port, converts the Apple II events into Linux compatible events, and inserts them into the input subsystem.
Theory of operation: Apple II Pi works by running code on the Apple II and the Raspberry Pi, talking to each other with a simple protocol. The Apple II basically appears to the Raspberry Pi as an external peripheral, not unlike a USB keyboard and mouse. The Apple II floppy boots into ProDOS and runs a simple machine language program that scans the keyboard, and mouse if present, sending the events out the serial port to the Raspberry Pi. It is a very simple protocol and the serial port is running at 115.2K baud, so it is fast and low overhead. On the Raspberry Pi, a little daemon runs, waiting for packets on the serial port, converts the Apple II events into Linux compatible events, and inserts them into the input subsystem. This daemon also has a socket interface (port 6502) that can be used to access the Apple II memory and execute arbitrary code. Look at a2lib.c for implementation.
Enjoy,