Tag: ftp

Introducing RAFTP — the Really Annoying File Transfer Protocol

I would like to describe a new and highly impractical method of transferring data between computers. Modern networks are getting more efficient every year. This protocol aims to reverse this trend, as RAFTP features:

  1. Slow file transfers
  2. A stubborn lack of error correction
  3. The ability to irritate neighbours while ensuring inaccurate transmission through playing the data over the air using Bell 202 tones.
doge-small-tx
Figure 1

Figure 1 shows a test image before it was converted into PGM format. This was then converted into an audio file using minimodem:

minimodem --tx -v 0.90 -f doge-small-1200.wav 1200 < doge-small-tx.pgm

This file was then transferred to an audio player. To ensure maximal palaver, the audio player was connected to a computer via a USB audio interface and a long, minimally-shielded audio cable. The output was captured as mp3 by Audacity as this file: RAFTP-demo

The mp3 file was then decoded back to an image:

madplay -o wav:- RAFTP-demo.mp3   | minimodem --rx -q -f - 1200 | rawtopgm 90 120 | pnmtopng > doge-small-rx.png

Figure 2 shows the received and decoded file:

Figure 2
Figure 2