Retrochallenge 2016/01 – DECnet over Radio

It’s that time of year. Another Retrochallenge is weeks away, and I’m completely not prepared.

The project I’m going to attempt is taking my two hobbies – Retrocomputing and ham radio – and combining them. Icom makes a ham radio that allows you to construct a point-to-point ethernet bridge at 128 kbps at 1.2 GHz – the Icom ID-1. This is mainly used for providing (slow) Internet services to the middle of nowhere, but my reading of the specifications show that this is a true ethernet bridge. If so, it should be able to bridge more than IP traffic, such as, for example, DECnet.

I intend to attempt to set up a point-to-point wireless ethernet link using 2 ID-1 radios. At one end of the link I will have a DEC InfoServer 100. The InfoServer is a magic DEC box that contains a CD ROM drive and allows for the remote installation of software using a protocol called MOP.

The other end of the link will have one of my many VAX machines with a blank drive. I will then remotely install the operating system. Once I have the operating system running, I will attach this machine to HECnet via the ethernet bridge.

Even though 128kbps is slow by today’s standards, it’s still quicker than many of the leased lines used in the original DECnet networks.

This should be enough work to keep me out of trouble, but still be achievable. Here goes!