{"id":303,"date":"2011-08-07T20:06:52","date_gmt":"2011-08-07T18:06:52","guid":{"rendered":"http:\/\/lallafa.de\/blog\/?page_id=303"},"modified":"2012-07-01T18:54:58","modified_gmt":"2012-07-01T16:54:58","slug":"plip2slip","status":"publish","type":"page","link":"https:\/\/lallafa.de\/blog\/amiga-projects\/plip2slip\/","title":{"rendered":"plip2slip"},"content":{"rendered":"

\"\"<\/a><\/h3>\n

Introduction<\/h3>\n

An Amiga 500<\/strong> has no special ethernet or other network ports for connecting to the Internet. Typically a SLIP<\/strong> (serial line internet protocol) device is used to transfer all IP packets via the serial RS 232 interface to another computer with fast ethernet connection. With the on-board serial port a maximum speed of 9600 Baud (~ 1 KiB\/s) could be achieved running Amiga OS.<\/p>\n

Faster speeds could be achieved by using a PLIP<\/strong> (parallel port IP) device that uses the parallel port to transfer IP packets to another host. Since the Amiga parallel port is fully bi-directional you can use a half-duplex protocol and then transfer an IP packet byte-by-byte over the port. This is done in the magPLIP driver available on Aminet.<\/a> Unfortunately, this approach requires an Amiga or another Computer with a fully bi-directional port on the peer side. With this parallel approach you can achieve up to 15-20 KiB\/s transfer speeds.<\/p>\n

The idea in this project is to use the custom I\/O ports of an AVR microcontroller<\/strong> board (here an Arduino 2009<\/strong>) and implement the parallel port there. The mcu implements the magPLIP protocol and can then receive and send packets to\/from the Amiga.<\/p>\n

On the other hand the Arduino uses an FTDI 232 USB-to-Serial bridge to allow fast serial data transfers. On a 16 MHz AVR you can use serial rates up to 500 KiBit\/s (~ 55 KiB\/s). With proper RTS\/CTS flow control the AVR can handle these data rates easily.<\/p>\n

The plip2slip firmware<\/strong> developed in this project now bridges these two ports. A PC is connected with a fast serial link to the AVR and the Amiga is connected with its parallel port. As a result the amiga can achieve full PLIP speed while the PC runs a fast SLIP link.<\/p>\n

On the PC I use Linux with a patched slipattach tool to support the fast serial rates. The Amiga magPLIP device is slightly patched to better support the AVR. All patches are available in this project.<\/p>\n

The data flow is as follows:
\n. Internet <->\u00c2\u00a0\u00c2\u00a0 PC\u00c2\u00a0\u00c2\u00a0 <--SLIP-->\u00c2\u00a0 Arduino\u00c2\u00a0 <--PLIP-->\u00c2\u00a0 Amiga 500
\n.\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0 Linux\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0 plip2slip\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0 magPLIP + AmiTCP<\/code><\/p>\n

Releases<\/h3>\n