Recent Posts

Ben Sinclair's avatar

PDP-11 Success!

After a lot of tinkering and some replacement parts, the PDP-11/23 seems to finally be running reliably!

The current configuration includes the 11/23 CPU, 64K of memory, and the serial interface. I also have my two RLV11 boards for running the RL02 drive installed, but those are not yet working.


I did have some bad memory boards, but I also didn't know that the CPU test required more than 32K of memory. So I did have everything working at one point, but the test wouldn't even start. With 64K of known good memory, it runs and passes!

My next step is getting the RL02 drive running, which may be very difficult if the complicated drive mechanism needs work.

Here it is running the CPU test:

CPU Test

Ben Sinclair's avatar

FileVault and Login Weirdness

I've been having strange login issues with my new Macbook Pro, and finally figured them out. It turns out that I didn't fully understand how FileVault encryption works.

I was seeing the following issues:

  • On restart, I would see a photo-based login screen, which wanted my iCloud password, then I would see another username/password login screen, which wanted my local password. Also, it was strangely focusing the password field instead of the username field.

  • The first login screen wasn't using my login preferences of username/password instead of photos.

  • Running in clamshell mode, I was never able to get the login screen to appear on my external monitor after a restart.

For the first issue, I tried all sorts of things, then decided to disable, then re-enable iCloud. After doing that, I only saw the initial photo-based login screen.

The second issue is where I realized everything was due to FileVault. No matter what I did with the login preferences, the login screen always showed the user photos and the shutdown/restart options, which I had disabled in preferences.

Eventually I figured out that with FileVault, the login screen is provided prior to OS X booting, which is necessary for it to decrypt and boot OS X. That login screen has no preference options, and always shows user photos. Disabling FileVault will cause only the actual OS X login screen to appear.

The third issue was also related to FileVault. When showing the FileVault login screen, it hasn't yet booted OS X, so it doesn't know about my external monitor.

I'd really prefer some control of the pre-OS X login screen, as I don't really want my actual name showing up on the login screen. I prefer just an empty username field. And of course it would be nice if it knew about my external monitor, but doing that without an OS might be pretty tricky.

So now I have to decide between wonky booting and logging in, or having strong encryption.

Ben Sinclair's avatar

Atom Editor

After much messing around with text editors, I've been using Github's Atom for a while now and really enjoy it! More on this and my semi-failed vim adventures later.


Ben Sinclair's avatar

Morse Code Gem

I forgot all about the Morse code gem I created a while back (2007), and just went to RubyGems to check it out. It turns out it has 3,341 downloads! I have no idea what those 3,341 are doing with it, but it's still fun.

Morse Code Gem

Ben Sinclair's avatar

HamClock for Apple Watch

HamClock version 2.5 is now available in the app store.

Here's what's new:

  • Fixed a 12H/24H time bug
  • Made the dates easier to read
  • Added Apple Watch support

With Apple Watch support you can now find your grid square and location from your watch! With the new watchOS updates announced today, a future update should allow me to show your grid square as a watch face complication.

Here are some promo codes for a free download. When they're gone, they're gone!

  • X4K7PKKFF39X
  • NKY3949WPTNL
  • NMXL63T4F74L

HamClock for Apple Watch