Amiga Network Peripherals


Commodore A2060 Network

> Company: Commodore International, US
Date: 1990
Amiga: 2000, 3000, 4000
Interface: Zorro 2
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