DevTerm by ClockworkPi

[mfleming]

I thought this new crowd-sourced device might be of some interest to forum members. The DevTerm is a small computer that is completely open-sourced, whose case and other parts are 3D-printed.



The DevTerm can be assembled without tools by snapping parts together. It includes a choice of several compute modules in M.2 format (I'm using the Raspberry Pi 3 compatible module running Raspbian). It has a full QUERTY keyboard, a 1280x480 display (double-wide VGA), and a thermal printer whose paper spool can be detached when not in use. There is also USB (3), WiFi, Bluetooth, and HDMI out.

I placed a preorder early in the year for delivery in May. Naturally it arrived on Friday (who knows a crowd-sourced project that ever shipped on time? Particularly in current circumstances.) It took only a couple of hours to assemble. I was quite pleased by the accuracy of the printed pieces and the clever way in which all the parts were assembled. The developers put a good deal of thought into the design and the way in which the PCBs are interconnected within the case. One PCB, the Ext. Module, is meant to be user designed and plugged in, the equivalent of an RPi hat. Several owners are already reported to be working on their own designs.

The keyboard connects to the main board via a four-pin pogo connector, has its own controller to communicate with the main board, and can also be replaced with a user designed keyboard. My first thought when I saw the DevTerm was "perfect HP-71B replacement!" One could take the keyboard design files, rearrange the key placement, and have a 71B with large display and printer. Well, in theory anyway. The keyboard is as wide as the 71B keyboard and half again as tall.

So, I'll load this guy up with some emulator programs and other software (SIMH comes to mind) and see how it performs. The keys are somewhat tiny and closely spaced, so I won't be writing the Great American Novel on the device, but the custom keyboard possibility certainly conjures up a few ideas. HP-97 workalike anyone?

~Mark

[BobVA]

Cool! Thanks for the preview! Could you post a couple of pictures when you have a chance? It seemed pretty small in the renders I'd seen earlier, but your comparison to an HP-71 makes me think of that in a different light.

What do you think of the printer?

[mfleming]

Still waiting for thermal paper to arrive! Here's a photo that will provide some sense of scale for the DevTerm. Next step, Emu71 under Wine...
   

[toml_12953]

(09-06-2021 01:09 AM)BobVA Wrote:  Cool! Thanks for the preview! Could you post a couple of pictures when you have a chance? It seemed pretty small in the renders I'd seen earlier, but your comparison to an HP-71 makes me think of that in a different light.

What do you think of the printer?

The website has lots of pictures but few units for sale at the moment, it seems.

https://www.clockworkpi.com/shop

[Garth Wilson]

It appears to be very nicely packaged.

(09-05-2021 10:31 PM)mfleming Wrote:  The keys are somewhat tiny and closely spaced, so I won't be writing the Great American Novel on the device, but the custom keyboard possibility certainly conjures up a few ideas.

In the late 1980's I was typing a lot on my HP-71, and could do 30wpm (a little over half what I can do on a full-size keyboard). When they discontinued the 71, I cut way back on the typing, figuring that if I wore out the keyboard and started having trouble with any of the keys, a replacement may not be available.

[Chr Yoko]

Interresting project. But the keyboard is quite far from the HP71B one....will need lot of re-tooling to become HP71B like. Maybe possible ?
Also great they decided to power it with 2x18650 Li ion cells ! They are hugely common now, in different flavors and from many suppliers , highly efficient and should be around for some decades.
Maybe the 21700 will supercede them however. At least for e-mobility applications (2 & 3 wheels mainly as 4 wheels are going to larger cells like 46800 or prismatics).

The arrows are bringing back memories of the MSX keyboard from 1980s :

[mfleming]

(09-08-2021 05:38 AM)toml_12953 Wrote:  [The website has lots of pictures but few units for sale at the moment, it seems.

https://www.clockworkpi.com/shop

They're still fulfilling preorders at the moment. I had a "Shipping label created" message from DHL for about ten days before the package was actually handed over. The packaging of the 3D printed parts & PCBs was also well designed. Wish I had taken some unboxing pictures.

Their previous GameBoy like device was featured on Amazon for a while, so it will be interesting to see where they are six months from now. Covid and chip shortages were among the problems they were battling!

I picked up a microHDMI to HDMI adapter yesterday so I'll try using it like an RPi later today . . .

[Sylvain Cote]

(09-08-2021 05:38 AM)toml_12953 Wrote:  The website has lots of pictures but few units for sale at the moment, it seems.

They told me that other options will be available in the coming weeks.
I will buy the A-0604 option when available.
Sylvain

[John Keith]

I would prefer the RPi CM4 but unfortunately it is a completely different form factor than the CM3. It would require a different main board.

[mfleming]

(09-08-2021 12:43 PM)Sylvain Cote Wrote:  They told me that other options will be available in the coming weeks.
I will buy the A-0604 option when available.
Sylvain

I'm planning to buy a more powerful compute module when available, but wanted to start with the RPi compatible for the software (Wolfram, Mathematica, Dyalog APL). Be warned though that the CM3 module seems to draw down the batteries significantly after six hours of inactivity. This may be the result of breaking in a set of new 18650's, or just a lack of power management on the part of the O/S.

Finally tested the thermal printer today and it works quite well. You simply redirect text to a "file" in /tmp, linked to /dev/pts/2 and it appears on the printer. The printer handler runs in user space, not kernel. The printer interprets Eos/Pos command set so you can set font size, image darkness, etc. Someone even posted a Bash function to output a PDF file to the printer. The main problem I see is a lack of a tear bar. If you try to tear the paper you usually succeed in detaching the paper holder first. Best to use scissors instead.

The microHDMI connector and my adapter didn't make very good contact (HDMI device is detected at boot time and only then enabled). It was amusing though to see the usual boot messaging scroll right to left rather than bottom to top. Best to enable and stick with SSH or VNC.

Finally, here are a couple of pictures I did manage to take of the box content before assembly. There are two separate plastic containers with snap on lids to retain parts, one with the 3D printed parts and the other with the electronics.
       
Definitely not a box o' parts, but a well crafted carrier...

~Mark

Postscript: Wine doesn't seem to run in the limited memory space of the CM3, so there goes my hope of running Emu71. Time to try J-F's DOS-based emulator.

[ijabbott]

Here's a nice review by "ETA Prime" (who is mostly interested in retro gaming capabilities):

[BobVA]

(09-07-2021 06:20 PM)mfleming Wrote:  ...Here's a photo that will provide some sense of scale for the DevTerm. Next step, Emu71 under Wine...

Thank you!

[mfleming]

(09-10-2021 12:49 AM)ijabbott Wrote:  Here's a nice review by "ETA Prime" (who is mostly interested in retro gaming capabilities):

Excellent video showing the packaging and parts, but I couldn't help wincing at the out of order assembly, particularly inserting the batteries half way through the process. Like they say, Kids, don't do this at home

Left my unit running overnight and it was dead in the morning. Hopefully the upower utility will have enough data to provide an accurate estimate of battery life.

[Xorand]

Until I saw the size comparison, this is what the device reminded me of.



The NEC PC-8201, the predecessor of the fabled Radio Shack TRS-80 Model 100.

[Didier Lachieze]

(09-14-2021 03:34 PM)Xorand Wrote:  Until I saw the size comparison, this is what the device reminded me of.
The NEC PC-8201, the predecessor of the fabled Radio Shack TRS-80 Model 100.

Quite close:



(picture from here)

[Xorand]

(09-14-2021 04:02 PM)Didier Lachieze Wrote:  Quite close:

I was going to say I'd be disappointed if someone hadn't already ported a M100 emulation to it.