Inspiration

Lately Hackaday has been my muse!

My MCM/70 Reproduction was inspired by Kristina Panos February 23, 2022 blog post: INPUTS OF INTEREST: CANADIAN MCM/70 WAS KINDA LIKE THE FIRST CYBERDECK. Here was a beautiful Canadian built personal computer from the mid 70s that I had no idea existed. I had to learn more.

The Commodore CHESSmate Reproduction I did was triggered by the November 14th, 2023 Maya Posch post: THE QUAINT HISTORY OF THE COMMODORE CHESSMATE in combination with having just met Peter R. Jennings, author of MicroChess. Fate? Coincidence? Either way I felt compelled to move forward.

With Al Williams July 19, 2024 post: RETRO CALCULATOR PANDERS TP TREKKIES... OR TREKKERS it was love at first sight. I was hooked by the whole retro future look of the Trekulator, and it didn't hurt the that units were made using my favorite blue color.

First Steps

I was lucky enough to find a sort of reasonably priced Trekulator for sale on eBay. It was just the unit itself with no box or instructions plus it doesn't power up (hence the lower cost). As usual, shipping and customs charges (I'm in Canada) added about 66% of the original cost to the total. Sigh. However, given the choice of trying to model something from an original or from photos, I'll pick (and pay for) a real object any day. The Trekulator photo at the top of this project is the one I purchased.

Perhaps a Phase Three project will be to try and get the Trekulator working, but right now I'm keen on 3D modelling the case as my first step.

Another Montage

Picture a montage of me printing and soldering and building all at fast-forward speeds. At this point, given the background and design described above, I went ahead and finished my Trekulator reproduction. If you are interested in the details of how this happened I would strongly encourage you to have a look at this project's logs for the complete picture. Here is a handy link: Project Logs.

Wrapping Up For Now

You will see in the logs that I managed to create a pretty faithful reproduction of the original Trekulator. I then went on to create a Next Generation Trekulator. Here is a quick video of it in action.

The main focus of the Next Generation version was the screen. I added the TFT touch display that had a built-in SD card reader. As you can see from the picture below, the actual TFT Display is not centered on the PCB.

As a result of this and because of space constraints I was not able to center the Display in the Trekulator window. I decided I needed a mask to expose just the central part of the screen. The end result is on the right below. I scaled the image of the original's cardboard backdrop and centered into the open area of the mask.

Lest you think that I sat down and finalized the look and function of the mask one and done style, think again.

As you can see I finished with a symmetrical look. In doing so I ended up covering part of the actual useable Display, mostly on the left hand side and the top. I started thinking about how I could take advantage of this situation and minimize the waste.

This is the back side of the mask. Along the top I added a row of five holes. I used the Bambu printers at Kwartzlab to print the mask in two colors, blue frame and transparent filament holes. This effectively created a row of five "light pipes". Because the holes are backed by the actual Display I'm able to "draw" colored circles behind the pipes to simulate Blinken lights.

I also created a column of three "buttons" on the left hand side as seen from the front. The red piece seen above fits into the slot with the three buttons pushing through the front and with only the base "strip" glued in. When the mask is in place, pushing the buttons applies pressure to the edge of the resistive touch screen...

One Last Power Move
Michael Gardi • 03/20/2025 at 15:28 • 0 comments

Now that the hardware and software is done I added a proper power plug and connected it to the ON/OFF switch.
It's Alive
Michael Gardi • 02/15/2025 at 16:10 • 0 comments

The calculator code has been added to my Trekulator reproduction. It seems to behave pretty well compared to the original. Here is a quick video:

So this is pretty much the end of phase 1, reproducing the original Trekulator functionality. Its now time to have some fun and extend the platform with more Star Trekie goodness.
New Keys
Michael Gardi • 02/12/2025 at 21:20 • 0 comments

I wasn't completely happy with the keypad keys that I had modeled and printed. Since my printer is only single color I had to extrude the key symbols up from the tops of the key caps and pause the print to switch filaments to change the color of the labels.

My local makerspace (Kwartzlab) now has three Bambu Lab P1S printers with AMS units, and I have been wanting to try out multi-color printing. So I tweaked the key cap models a bit so that the labels were separate "bodies" (objects) inserted into the keys. This allows you to assign different colors to the key and the label in Bambu Studio. At the same time I adjusted the label sketches so that the strokes were at least .8 mm wide. This ensured that they were "drawn" with at least two "lines" of filament.

The result was very satisfying.

On the left my original key caps printed on my Prusa MK3S+. In the middle caps with my new and improved labels. Of necessity, labels are still a bit larger than the original Trekulators so they can be printed with a .4 mm nozzle, but they are much better defined now and they don't have a rough feel since the labels are flush with the key tops now.

Definitely worth the effort.
Yikes!
Michael Gardi • 02/10/2025 at 22:48 • 0 comments

This just popped up on my eBay feed.

Here is the link: RARE! 1976 Mego STAR TREK - STAR TREKULATOR (Calculator) LIGHTS & SOUND CM2739.

It's in terrific condition, but the starting bid of US $599.99 is a non-starter for me.
Some Finishing Touches
Michael Gardi • 02/03/2025 at 20:59 • 0 comments

I added an ON/OFF switch. It's not wired yet but ready to go.
I recreated the Trekulator decal. I was going to have it printed white on transparency only to learn that my local copy place does not stock white toner for their printers, who knew. So I had to settle for grey which looks fine.
For version 1, I reproduced the still image of Kirk, Spock, and Uhura and just mounted it over the TFT display. I had punched out the holes where the LEDs would have gone. My intention for version 1 was to light up the screen behind these holes red to simulate the LEDs, but while integration testing I noticed the following.
I was running "The Game of Life" to test TFT display. You can see the "active" cells blinking behind the LED holes. Reminds me of static. I think it looks pretty cool so I will likely try to show tiny little "displays" where the LEDs would have been.
Finally I added a translucent blue gel over the 7_Segment display to tone down the bright red a bit and mask the display structure so that you only see the segments when they are lit.
I think I've been procrastinating a bit on the software side. No excuses now.
Packaging
Michael Gardi • 01/27/2025 at 17:01 • 0 comments

The "wiring" PCBs arrived, so I added the required headers to attach the ESP-32 to the rest of the components.

I soldered in sockets for the ESP-32 and I2S board.

Thankfully assembly went well. SparkFun Electronics has some nice "Jumper Cables" in short lengths (4", 6", and 12") with many pin number options. They worked out great in this case. I designed and printed some clips to hold the wires flat as there is not that much clearance to the bottom of the case.

The PCBs and TFT are held in place by L shaped tabs, and the 7-Segment display is screwed on so that it would be easy to print an new case and swap the electronics into it.

I still have to add an external power connector and front panel switch (I'm temporarily running in a USB cable to power the Trekulator and so I can program the ESP-32), but the hardware is basically done.
Time to write a calculator program.
Wire Wrangling
Michael Gardi • 01/14/2025 at 20:32 • 0 comments

With all of the Trekulator components wired and tested I turned to packaging everything into the case. I had already decided that I would create a PCB to bring some order to the wiring chaos.

I think there are a couple of I/O pins still available on the ESP32 but not many. So I got to work on the PCB.

After struggling a bit to get the last couple of traces attached without having to create a via, I broke down and decided to just do a 4-layer board. For the cost difference in fabrication, for what is essentially a one-off, I decided it was worth it.

As I mentioned in a previous log, this PCB is the same size as the KeyPad PCB and will be installed directly above the KeyPad.
Mounting the TFT Display
Michael Gardi • 01/14/2025 at 19:51 • 0 comments

I modified the Trekulator large display model to include an indentation to mount the TFT Display. As with the keyboard/CPU panels, tabs are used to secure the display in place.

With this change the inside of the case is 95% done. I still have to work in an external power connector and ON/OFF switch.
Adding a TFT Display
Michael Gardi • 01/14/2025 at 17:33 • 0 comments

The original Trekulator has four red LEDs imbedded into the still picture of Kirk, Spock, and Uhura.

I was about to start adding these when I had a thought. My intention all along was to mount a real display back there for my Next Generation implementation. It occurred to me that with a display I could easily emulate the LEDs for an "authentic" original experience so I decided to avoid some rework and jump directly to adding a display.

I had purchased a 3.5 Inch TFT Display for this purpose. It has 480 x 320 resolution, a touch screen, and an integrated SD card reader; all of which use an SPI interface keeping the I/O pin count down. The display is based on the ILI8488 driver chip which is well supported library wise. These modules are readily available and relatively cheap.

The screen itself is not wide enough to fill the whole Trekulator display area, but the height is pretty close so I think I can make this work.

I added the display/touch/SD card to my breadboard and wired it to the ESP32. I removed the Adafruit MicroSD Card Breakout Board since I no longer needed it. I am using the TFT_eSPI library to communicate with the display devices. The library come with many great examples to test the device. Below is a "Cellular Automata" test of the display.

I also tested the SD Card and touch capabilities. With the display working, all of the components for my Trekulator reproduction are in place. Now I just have to figure out how to cram all of this into the case, and oh ya write calculator program.
Mounting the Keypad
Michael Gardi • 12/12/2024 at 16:36 • 0 comments

I designed a mounting block for the Trekulator keypad.

I attached this with CA glue to the back of the front panel. To ensure the alignment of the keys with the holes I glued the mounting block to the back with the fully populated PCB in place.

With the keypad PCB in place I added the spacer ring (right side of the first image above). I created the block with a depth that can accommodate two PCBs. I did this having decided that I will create a second PCB to hold the ESP32, I2S, microSD reader, and amplifier cards. This second PCB will be the same size as the keypad and will greatly simplify the overall Trekulator wiring. In the rightmost picture immediately above I have used a keypad PCB as a placeholder for this new board, and used some 3D printed clips to hold everything in place.