With several hundred kits sold, it seemed like time to add a space (NOT a blog, I swear) for passing along random notes that might prove useful or interesting, or both. New stuff generally toward the bottom; note that some links may have expired. Feel free to e-mail your own comments and ideas.

The weakest link: Rubber bands. Like people, they will relax over time if you leave 'em stretched out... so it's a good idea to unhook them if your Digi-Comp is going "off line" for awhile. A simple DIY tip for replacement: the Size 10s we use are uncommon, but go get some longer ones of the same width (1/8 inch, 1.5 mm). Take a band, tie a knot in the middle, and snip off one side—leaving a small loop with a knot.

Speaking of rubber bands: If your input rods aren't snapping into place like they used to, and you're up for a few minutes of additional cutting and gluing, here's a PDF construction tip to boost the tension of tired (or slightly oversized) rubber bands.

DC gathering dust? Ours was, literally. Looked so durn purty, we just left it out on the table, and dust happens. So we recently made a dust cover out of a sheet of overhead transparency (mylar) film. If you happen to have a sheet, try it. Make a sharp right-angle crease along one edge, then tuck that edge under the uprights at the rear (snip away one corner of the film if necessary so it fits in). Then make several parallel creases close together so the cover conforms to the beveled corner. Finally, another sharp crease to lock it precisely over the front edge, and trim off the rest. Unfortunately, a standard 11-inch sheet doesn't extend all the way around. To extend coverage to the front, use legal size (14-inch) transparency film, or, less elegantly, tape a second sheet to the first. Either way, it will keep the dust at bay.

Problems, problems: If you've zipped through the v2.0 manual and are seeking even more experiments and challenges, check out More Fun for Digi-Comp I  by Bill Kustes (revised edition, June 2008). With nearly 50 new activities including games, magic tricks, puzzles and the like, it's reasonably priced at $21 in book or CD form ($35 for both; the CD features color clip art) plus $4 US shipping. Contact WilliamKustesATbellsouth.net directly to purchase or to see the Table of Contents. Note that Bill's book uses the original DCI nomenclature, but "translating" is simple—see the key on p47 of the v2.0 manual. Addendum, Jan. 2026: We note with sadness the passing of Mr. Kustes, a retired chemical engineer, for many years a loyal contributor to the FriendsOfDigiComp group.

Supply side issues: As of early 2008, the colorful Solo brand "Neon" drinking straws (i.e. input-output tubes) we've been shipping with the kit appear to have disappeared from the market. FYI, drinking straws vary considerably in quality, and those particular straws were the sturdiest, which is why the DC1 v2.0 input/output system was engineered to use them. We haven't found any other brand with the same strength—and matching the inside diameter is an issue, too (even a millimeter makes a difference). What we have stumbled upon is an online source of plain white Solo straws with the same specs as the colorful Neon ones, so until further notice that's what will be shipping. They're more expensive, but kit price won't change. For purists, this may be actually be an improvement: now the kit is entirely red-and-white, just like the original. 

Update, early 2009: With the 8th production run coming up soon, we're about to run out of the white Solo straws (see above), and nobody's got 'em in quantities under 12,000. At five straws per kit, I'm just not thinking that far ahead. Fortunately, we've located a comparably robust straw with matching specs, from a US-based manufacturer, and laid in a reasonable supply. The new I/O tubes will be translucent, rather than white or neon. Less colorful, perhaps... but they'll provide better operational "visibility." Now you'll be able to read the numeral on a tab, even after a tube has been inserted.

Update, mid-2013: With the 2009 batch of straws running out, an intensive Web search for replacements proved futile. Our preferred straw is now sold only through mid-level wholesalers, and the market as a whole is trending toward biodegradables, which I wouldn't trust for construction (or over time). However, through the good graces of the manufacturer's rep, we were able to obtain a "small" quantity (several thousand) of our current item as samples, enough to keep us going for a few more years. 

Smithsonian takes note: A few years ago, an original Digi-Comp I was on display in the main-hall exhibition Mobilizing Minds: Teaching Math and Science in the Age of Sputnik, right alongside a Gilbert chemistry set and a Visible Man/Visible Woman! Here's the online exhibit and the Smithsonian's collection entry for the DC1. 

Coverage: Thanks to Larry Groebe and the following sites for spreading the word and giving us a March '06 Blip: www.retrothing.com, www.boingboing.net, www.engadget.com, www.makezine.com, www.technovelty.de, www.golem.de, Computer Collector Newsletter. ... Thanks to Evan Koblentz for inviting us down to VCF (Vintage Computer Festival) East in mid-May. ... And also to MAKE magazine for their blurb in issue #6 and further encouragement to contribute a two-page article on the kit, which appears in issue #7 and online. ... Word of the kit continues to spread, mysteriously and in various languages (Wikipedia mention probably helps). ... On this Japanese page (at least according to the old BabelFish page-translator) recent customer Housuke Nojiri exclaims: "Such a funny potato it is it is!" 

4-bit Digi-Comps: On the Yahoo forum (Fall 2010), Kurt Kammeyer announced completion of a brassy, 2.5-pound Steampunk version ("DIGICOMP IV"), with 4 flip-flops and a 4-bit readout. Meanwhile, we'd spent an evening or two hacking our own Chop Shop Edition, derived (with some careful cutting and gluing) from about 1.5 kit's worth of standard parts. You'll note the sliders have migrated to the bottom, to make room for the extra flip-flop, so we can use the same wire rods. Just an experiment... but it works! Now, can we come up with some interesting problems to solve in this vastly expanded computational universe?

1000+ sold: Mid-summer 2012, and we've passed the thousand mark. Thanks to all of our (apparently) happy kit customers! In all this time, no shipment has gone astray and -- aside from a few snide remarks about the website using frames (which it still does, proudly) -- no one's had anything but kind words for the DC1v2.0. 

Shine on: As of October 2013, control rods are now being fabricated of precoated zinc music wire (piano wire), which is sturdier/less bendy than the previous "basic galvanized" stock and—so the fabricator assures us—will retain its shine longer.

More Coverage: In mid-November 2014, the tranquil pace of sales unaccountably picked up, pushing us past the 1200 mark in sales, even exhausting components for a week or so pending a successful (if accelerated) 13th production run. No doubt the spike in interest followed this article on vintage science kits in the December issue of Discover magazine. I have no clue how author Jim Sullivan latched onto the DC1, but thanks for mentioning the kit. (Note: The sorry state of the original specimen in his photo is a good argument for investing in a nice new model!)

Supply-side heads-up: Since the kit's inception, we had been using gray foam board (Elmer's #95204) for the base plates, selecting unmarred individual sheets at brick & mortar suppliers like Staples. As of December 2014, the 95204 had vanished from stores in northern NJ. For several months we opted to ship kits using a decent alternative (#95206, "Beige Sandstone"). Meanwhile, Staples introduced its own two-sided (bicolor) line of foam board, but having finally found a reliable mail-order supplier for the 95204, we'll be returning to that good old single-sided gray in mid-April. Those of you who got Sandstone kits can regard them as a Limited Edition of sorts. Any feedback on color choice is welcome!

DC as a video game? The folks at the World Video Game Hall of Fame, part of the Strong National Museum of Play in Rochester (NY), have seen fit to include Digi in their History of Video Games in 64 Objects (Dey Street Books, 2018). The two-page writeup, preceded by a full-color DPS photo of an original DC1—sadly lacking its input/output tubes—touts the device as “a great gender equalizer” whose “packaging featured a young boy and a young girl, both taking part in programming the machine.” Hmm... our kit orders over the past dozen years don’t exactly bear that out: maybe 95% have gone out to guys. Which doesn’t alter the fact that this is a gender-neutral toy, if ever there was one.

Where in the world...? As we celebrate a 15th year for the DC1v2.0, let's also celebrate the far-flung places outside the US where the kit has landed in that time. Ready? Here we go (in order of adoption): United Kingdom, Germany, Japan, Netherlands, Canada, South Africa, France, Spain, Finland, Austria, Australia, Italy, Norway, New Zealand, Sweden, Abu Dhabi, Switzerland, Israel, Mexico, Portugal, Croatia, Brazil, South Korea, Poland, Czech Republic, Faroe Islands, Russia, Ireland, Denmark, Thailand, Luxembourg, and most recently (Dec 2019) two kits to Taiwan.

Pause for the Cause: We are sixteen, going on seventeen... and concentrating more these days on fleshing out the still-offline version of this site, as originally conceived. Time for Digi-Comp to take a back seat and amuse itself quietly with a Nintendo Switch (or better yet, just stare out the window) while we put pedal to the metal. Hopefully the kit will be back in production by June of 2022. Email me to convey your pent-up demand!

Hiatus terminus: As of July 2022, we are back in production with another batch of die-cut boards, our first since pre-covid days. We've used the same suppliers for over 15 years, and fortunately they're all still afloat, but the paper industry in general has been hard hit. We had to go with lighter (135 gsm), "glossy" stock as opposed to the slightly denser (170 gsm) "ultra glossy" paper of past kits. Results were fine, but our printer was busier than expected because so many of his competitors have shut down. Then the die-cutter erred in trimming down large sheets of binder's board to the 9x12s supplied in the kit. Only after the first die-cutting run did we realize the grain of the finished boards was running the wrong way, weakening the longer pieces. Back to Square One, with another printing run, and the die-cutter making good on the error. Thanks for your patience during the interval. Good to be back.

Hot off the press: This time around (June, 2024), a flawless fabrication cycle, and another batch of a hundred or so. Here's the final stage, as César grabs the top board from a stack of printed/mounted sheets, and prepares to run it through the diecut press. Meanwhile, I'm inspecting the output and filling the foreground box with ready-to-ship sheets. Proprietor Vic tells me the original die blades are losing sharpness (we know the feeling), and it could be time for re-knifing. Fortunately, César is a master of the make-ready, an intermediate sheet of paper and tape that locally fine-tunes the machine's pressure, and has been getting it right for nearly 20 years.