SL3MEGA
ATMEGA8515 based ethernet MP3 player
This 20 year old project of mine claims to be the smallest internet operating system, written in 100% AVR assembler, that includes everything from Ethernet (RTL8019AS) driver, DLC, ARP, IP, ICMP, TCP streaming to a hardware MP3 decoder chip (VLSI 1001K) and some simple FTP client incl. a little GUI for a 5x7 dot matrix LCD within 3472 bytes Flash ROM of the AVR. Yes only 3.4kbytes of Flash and 64k of external SRAM - not more than this is needed to listen to a MP3 transferred from a FTP server...