Commodore, USA
A2000, A3000, A4000
Zorro II
Autoconfig ID
514 / 8,9
    Arcnet interface
  • developed from the Ameristar Arcnet Controller
  • Arcnet networking system - old, slow but cheap and reliable, useful for small LANs and simple network sharing
  • Arcnet requires RG62 coaxial cable instead of the RG58 used on Ethernet systems
  • uses 93 ohm terminators opposed to the 50 ohm used by Ethernet
  • the Arcnet interface hybrid chip comes in two different versions, HCY 9058 for bus networks and HCY 9068 for star networks
    • the manual says the card uses a bus network layout with up to 256 nodes but many A2060s has 9068 hybrids for a star network layout allowing only four cards to be connected together
    • to solve this the HCY 9068 can be simply replaced with a HCY 9058 chip
  • interrupt driven (polled I/O) - one interrupt on the Amiga yields into a busy system
  • to reduce traffic the driver uses the Arcnet hardware's four buffer as a single FIFO buffer
  • the badly written driver (a2060.device) has some bugs in the FIFO buffer which results in lost packets and packet collisions - increased traffic on the Arcnet bus
  • manual says 2.5 Mbit/s (300 kB/s) transfer speed but only max 100 kB/s is achievable
  • socket for optional network autoboot ROM
  • bus activity LED connector
  • supported by NetBSD and OpenBSD
Commodore A2060 -  front side
front side
Commodore A2060 -  back side
back side