Classic BSG Viper Pilot Leg Computer Build

When piloting the galaxy, don't forget your Sharp slide rule calculators... er... your Leg Computer.

The production certainly had a deal with Sharp. Any time a calculator showed up, it was Sharp branded... usually underneath a label of some sort to obscure the fact. There were two styles of Leg Computers. Both utilized the MXU-63/P lighted pilot kneeboard but had different calculators. The first was likely an early production test using the EL-8133 calcs. It was mainly seen in early production photos and was simply two calculators attached to an unmodified kneeboard. The second utilized modified kneeboard with a custom vacuformed tray attached to hold two EL-5804 slide rule calcs. It also housed some cool blinky lights. It is the version that is most recognizable. While visually cool, it didn't see much screen time. After buying a vintage kneeboard for my personal cosplay I think I know why. These things have a nasty habit of sliding down your leg while walking around. Makes sense. Good pilots tend to stay seated while flying. But the production probably decided they were too much trouble and it quickly became a background prop only. It also shows up in Buck Rogers in the 25th Century in various forms.

Reference shots...



I decided to create an idealized version of this prop. Acquiring vintage kneeboards is bothersome and the price fluctuates quite a bit. Also feel a modified design would create a more streamlined and otherworldly look. Perhaps something that the production might have done with time and resources to further obscure the origin of this prop.

Using screen caps, I stared with the basic shape sized to fit my kneeboard base and hold two vintage calculators....



The blinky lights in the middle sit underneath a clear sheet which, from the screen caps, seems to be angled so I made sure to include that element. The map light lens is from my authentic kneeboard, stripped of paint. I'll be molding and casting that in clear resin...


Using the base plate of my kneeboard. Had to do quite a bit of repair work here, filling holes, etc...


Design of the top tray finished and ready for molding. The clear lens will mount to the "L" and LEDs will be housed in the sockets. Also a battery compartment...


Time for the fun part. Building the electronic circuit. I did my best to sync the timing to that seen on the pilot episode, "Saga Of A Star World." A bit difficult given the original prop used grain-of-wheat bulbs that brighten-and-fade vs. the instant on-off of LEDs. After finalizing the design, sent off the Gerber file to the PCB house...


Another difficult item to locate is the EL-5804 so I molded the components for a replica. I'll be casting the keys using custom dyed resin and decorating the replicas using custom decals for an authentic look...


First cast of the top tray and test fit of an authentic EL-5804 and unfinished replica...


First prototype assembly with my authentic calculators. The original props used some form of metallic tape to cover the Sharp logo. I opted for a resin replica of the tape. I think it looks more substantial, perhaps like a heat sink or some other functional component...


To be continued...
Last edited:
Re: Classic BSG Viper Pilot Leg Computer

Now for the obligatory Bionic Moon Labs parody fan film.

If you grew up watching 70s late night TV and remember any K-Tel Records commercials, you might enjoy this.

Once thought lost forever during the Cylon destruction of the Colonies, this groundbreaking late night GalactiPod commercial has been located in a damaged data archive and restored for viewing. We apologize for the poor quality of this video...

Last edited by a moderator:


Legendary Member
Re: Classic BSG Viper Pilot Leg Computer

Another awesome prop from you! :thumbsup

I remember when I was issued my first one and thought it was so cool until I found out few wore them for fear of busting a kneecap if you ever had to eject

Your message may be considered spam for the following reasons:

  1. Your new thread title is very short, and likely is unhelpful.
  2. Your reply is very short and likely does not add anything to the thread.
  3. Your reply is very long and likely does not add anything to the thread.
  4. It is very likely that it does not need any further discussion and thus bumping it serves no purpose.
  5. Your message is mostly quotes or spoilers.
  6. Your reply has occurred very quickly after a previous reply and likely does not add anything to the thread.
  7. This thread is locked.