A 2003 model SLIMP3 bought Jan 2009. 

Comes with 2.3 firmware.

SLIMP3 hardware

From the wayback machine, circa 2003, specs for the SLIMP3:



  • Dimensions: 8.5"W x 2.5"H x 2"D
  • Display: Noritake 40x2 VFD
  • CPU: Microchip PIC16F877 microcontroller
  • Ethernet controller: Crystal CS8900A 10Mbps embedded Ethernet chip
  • DMA controller: proprietary logic, Xilinx XC95144XL
  • MP3 decoder: Micronas MAS3507D
  • DAC: Crystal CS4334, 16-bit 44Khz
  • Buffer RAM: 1Mb (8 seconds at 128Kbps)
  • ROM: Rewritable flash program memory, EEPROM configuration memory
  • IR: Standard 40Khz IR receiver
  • Power supply: comes with 5V 1600mA power supply, player uses 700ma (max)



  • Support for subnets/gateways (see documentation section on WANs)
  • Open UDP-based streaming and control protocols



  • Open-source, high-speed, embedded IP protocol stack
  • Written entirely in assembler, for performance and compactness
  • General-purpose architecture offloads most of the application to the server side - new features can be added without making changes to the low-level firmware (protocols, device drivers)
  • Integrated boot-loader program includes its own copy of the IP stack and necessary drivers, so that the entire MP3 player application may be reinstalled over the network.

SqueezeCenter is running on a QNAP TS409 Turbo NAS

Powered up the unit after connecting to Network, Stereo & Power.  DHCP worked, and it found the SqueezeCenter server ok and was recognised in turn by SqueezeCenter.

Turned off a bunch of Plugins.

RSS feeds in the middle of songs.  Nice wide VF display.

Slimp3 protocol:


Field nameTypeDescriptionVersions
slimp3.control Boolean Control Packet 0.99.0 to 1.0.5 Boolean Data 0.99.0 to 1.0.5
slimp3.data_ack Boolean Data Ack 0.99.0 to 1.0.5
slimp3.data_req Boolean Data Request 0.99.0 to 1.0.5
slimp3.discovery_req Boolean Discovery Request 0.99.0 to 1.0.5
slimp3.discovery_response Boolean Discovery Response 0.99.0 to 1.0.5
slimp3.display Boolean Display 0.99.0 to 1.0.5
slimp3.hello Boolean Hello 0.99.0 to 1.0.5
slimp3.i2c Boolean I2C 0.99.0 to 1.0.5 Unsigned 32-bit integer Infrared 0.99.0 to 1.0.5
slimp3.opcode Unsigned 8-bit integer Opcode 0.99.0 to 1.0.5



Software Players