Project frustration

I need to vent….

I’m working on what I hoped would be an easy little project. I fell in love with the replica computers created by Obsolescence Guaranteed, and decided to get a PiDP-11. Yes, I had worked with PDP-8s and a PDP-10 long before I got my hands on an 11, but there’s a lot more you can do with an 11, including running Unix V6 and V7! I knew my limitations, however (I’ve never been very good at soldering), and so I bought a pre-assembled model. All I needed to do was add a Raspberry Pi, and I’d be in business….

While I was waiting for the PiDP11 to arrive, I decided to familiarise myself with the SIMH software that underpins this and many other computer system simulations. I grabbed the nearest hacking laptop (which happened to have Fedora installed on it), and immediately ran into the tangle of issues that plagues so much open source. First, I learned about the split between SIMH and OpenSIMH. Then I found that the latest OpenSIMH on Github wouldn’t build (because you have to build from source – this is FOSS 🙄) because… something to do with CMake on Fedora. And everything seemed to depend on a bunch of shell scripts that looked like they’d only been tested on Ubuntu but didn’t work on Fedora. Sigh. I looked for pre-built binaries for Windows or Mac, failed, and decided to wait for the hardware.

My assembled PiDP-11 arrived, complete with a preloaded microSD card for the Raspberry Pi. I hooked up a nice new Pi 4 Model B to a screen and keyboard, booted it, and everything worked just fine. But before I installed the Pi into the PiDP-11 case, there was one more thing I needed to set up. I wasn’t planning to leave everything hooked up to an HDMI display and USB keyboard, so I needed a way to log in to the system via ssh over WiFi. So I created two new accounts on the Pi: one for remote admin, and one as a virtual terminal for the PiDP-11. I enabled WiFi and ssh on the Pi, booted it up, and successfully ssh‘d in from a Windows laptop. (I discovered that Windows Terminal now includes an ssh client – nice!) To find out the IP address of the Pi, I logged in to my Netgear Nighthawk router and looked at the list of connected devices. Excellent. All set. Except….

How could I be sure that the Pi would always get that IP address? DHCP hands out addresses on a first come, first served basis. Clearly I needed to assign a static address to the Pi. So I logged in to the Nighthawk, navigated to LAN Configuration, tried to assign an address, and failed with “Bad MAC address”. I consulted the Internet…. and discovered that the Nighthawk firmware has been broken for over a year, and the community has been yelling at Netgear to fix the Address Assignment bug, to no avail. 🤬

I really didn’t want to have to buy a new WiFi AP/router. But I think I’ll have to.

UPDATE: I decided to use the opportunity to upgrade our home WiFi to support WiFi 7. Future-proofing, I hope…..

2 thoughts on “Project frustration

  1. Cost: $440 for a pre-built PiDP-11, inc. shipping; $119 for a Canakit Raspberry Pi 4 4GB kit from Amazon, and $9.99 for a micro HDMI to HDMI adapter, also from Amazon. (I already had an HDMI monitor, USB keyboard, and various USB cables and adapters.)

  2. I use a Pi3b running pi-hole to do my DNS and DHCP. For the hosts I want at fixed addresses in my network (like my macbook which I route a couple of ports to from the router), I assign fixed addresses in the DHCP configuration.

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