Digirule 2U

I keep meaning to post about SISEA, but like… I don’t have anything to say that others haven’t said better. Much like SESTA/FOSTA, this bill is a direct attack on sex workers under a thin anti-trafficking guise. Listen to what sex workers are saying about this. Contact the folks who are supposed to listen to us. Let’s do what we can to stop this garbage.

I’ve written about single board computers before, and have bought and briefly played with a modern board from Wichit Sirichote. I’d meant to write about my experience with this board, but I haven’t actually gotten too far into the weeds with it yet. I need to either find a wall-wart that will power it, or else hook up my bench supply to mess with it, and… my attention span hasn’t always proven up to the task. I will say that it does what it’s supposed to do, at a reasonable price; a fun little hobby board.

Recently, however, I received something very interesting. Funded on Kickstarter, and not yet present in its current version on the creator’s website, the Digirule 2U is a single-board computer in a ruler-sized form factor. It has two 8-bit binary display LED arrays, pushbutton inputs that somewhat mimic classic machines like the MITS Altair, and is powered by a single CR2032. It’s not based on any classic microprocessor, but its opcode mnemonics are instantly recognizable to anyone familiar with entering machine code into an old machine. It has 54 instructions, all of these are beautifully silkscreened onto the back of the machine, alongside the handful of relevant reserved system memory addresses.

This all means that without having to connect to a power supply, without having to read any outside reference material, the Digirule 2U is an entirely self-contained 8-bit hobby computer sized like a chunky bookmark. I was able to quickly write a program to show adding (in binary, of course) from 0-255. There are no conditionals in this little demo, so when the location overflows, it just starts at zero again.

0: 00000010
1: 10000000 #set speed to 128
2: 00000011 #initialize stack pointer
3: 00000101
4: 00000000
5: 11111111 #load value 0 into the data display register
6: 00011110
7: 11111111 #increment the data display register
8: 00101000
9: 00000110 #goto 6

An incredibly simple ‘hello world’ sort of demonstration, but again… the only reference material I used was the list of opcodes silkscreened on the rear of the computer.

This is the third iteration, after the (largely identical to one another, I believe) Digirule 2 and 2A. I haven’t used the earlier Digirules, but the 2U seems like a big step up. It adds serial communication including ASCII terminal access and file transfer. This is something I’ll check out in the future, but it’s not really the point of the device to me. The 2U also adds over 20 instructions including niceties like multiplication and division; the earlier instruction set was certainly sufficient, but the 2U’s fills out some helpful areas.

I love this little thing. It’s a small, clever throwback to hobbyist and developer’s single-board computers of the early 8-bit era. The packaging is brilliant, removing all of the friction from just powering it on and tinkering with some machine code. It’s the same sort of fun that I get from casually messing with an old HP calculator or code-golfing in dc. Hopefully I’ll come up with some little challenges for myself and post an update or two in the future.


Medium/Message: Music and Medium

A new series! I have at least two posts planned for this series, and hopefully I’ll come up with more in the future. The idea is to highlight art that is inseparable from the medium used to record and/or distribute it. As far as this post is concerned, I want to discuss creative uses of the media that a consumer would purchase. Particularly, music or musical experiences that couldn’t exist outside of the medium they were made for. Certainly various technologies and media have had convenience features like CD zero-indices being used for skippable track intros or records being sided out of order for automatic record changers. But some creative folks have really exploited features of specific media for far more interesting purposes. I personally find this extremely compelling; I hesitate to say it elevates an art form when the reality is a bit more complicated. It’s the creation of something new, merging form and medium into a uniquely intertwined experience. And while the end result may be a bit gimmicky, it is also often something with some level of transience or interactivity.

Mike Oldfield – Tubular Bells (Commodore 64 Software)

I’m starting with this one because it’s a bit of a stretch. Honestly, I thought I had three perfect fits for this post picked out, but could only dig the following two out of my brain. Maybe this was the third all along, stretch or not. At any rate, in 1973, an eighteen-year-old Mike Oldfield released an album that, among other things, launched Virgin Records. Tubular Bells took the world by storm, and Oldfield… took note of that, following the album with multiple live recordings and sequels. But one of the weirdest things to come out of this was 1986’s Commodore 64 rendition of the album. ROM sites are constantly moving around, but you can pretty much get the whole picture from this recording on YouTube.

This gets interesting to me as it intersects with 8-bit computing. The C64 was about as much of a staple as one could imagine a computer to be in American homes at the time. Among other things, it had the SID chip, a groundbreaking sound chip that (without digging too deep) combined analog and digital stages for a sound that remains unique to this day. This lead to some absolute bangers for video game sound design, but it also seemingly gave Mike Oldfield and the team at Computer Rentals Limited the confidence to create an interactive, fully synthesized and computer-controlled rendition of Tubular Bells.

So, despite this being a bit of a stretch, this is where I think we have a novel usage of medium, likely the first of its kind. Home music visualizers already existed, like the failed Atari Video Music device, and commercial music videos had already leaned on computer animation. And while the C64 version of Tubular Bells feels like something out of the demoscene – it isn’t1; it was a commercially available, Oldfield-approved product. To my knowledge, this was the first time all of these things came together – a commercial release of software for a popular device with an interesting and capable sound chip that offered up a rendition of an album with interactive visualization elements. While you can’t do much, you can change tracks, alter the colors, switch between disparate dots and lines, and alter symmetry. This wasn’t possible with even the fanciest of video formats, LaserDisc; it was only possible to combine known visuals with known audio and incorporate interactivity using software. The idea didn’t really take off, but the C64 version of Tubular Bells represents a unique meshing of viable product on a medium and tech optimism.

GESCOM – Mini Disc (MiniDisc)

Unlike the obviously Compact Disc-based CD-R(W), MiniDisc was designed from the ground up to be a consumer-rewritable format. Rewritable discs were available from the outset, and they differed significantly from rewritable CD-RWs. Many of these differences don’t matter for the purposes of this post, but one that does is that recording was done much more akin to how we think of rewritable computer media. That is to say, recording doesn’t need to be done in a tidy, serial manner; bits and boops of a track can be all over the physical disc. This means that buffering was built in to the spec, a requirement of every player. And this means that every player also offered, for the first time, a guarantee of gapless random access.

Mini Disc by GESCOM (a side project of Autechre that released… this one album) exploited this very fact. The idea was that every track could… sort of kind of lead into every other track. You’d pop in the MD, set it to random, and hear a different experience every time. This would be possible with a CD if gaps were accepted, but… for a project like this, they simply aren’t. And weren’t. And so, Mini Disc was a release that could only exist on its namesake. Nowadays, file-based music playback is utterly commonplace, and gapless isn’t so hard to find. Mini Disc is, thus, available for download these days, but at the time… this was a feature that was basically unique to MD.

Various Artists – RRR-100, RRR-500, and RRR-1000 by RRRecords (Vinyl record)

The typical way that a vinyl record works is that audio information is stored in a single long groove that runs in a continuous spiral from the outer edge of the disc toward the center. The fact that the stylus just ‘rides’ ambivalently in the groove can be exploited, however. It already is in some of the basic convenience mechanisms that make records usable, like the locked groove at the end that keeps the stylus from careening into the label and/or spindle, and the widely-spaced areas that make the breaks between tracks visible. But other, more creative things can be exploited here as well, like multiple spiral grooves running in parallel with each other, or in the case of RRR-100, RRR-500, and RRR-1000, a ton of locked grooves containing short looping samples in lieu of a traditional spiral.

RRRecords released three of these: RRR-100 has 100 loops on a 7″ and RRR-500 and RRR-1000 have 500 and 1000 loops respectively on 12″s. These weren’t studio beats meant for DJs to use or anything along those lines, but weird little noise and industrial type tracks, each made by a different artist2. Some of these artists were quite prominent; among (hundreds) others, Merzbow, Aube, and Terry Riley made appearances. Due to the sheer density of tracks on the record, knowing what you’re listening to is nearly impossible, despite having a tracklisting. Any given needle drop is, to an extent, random because of this. This instant access to quasi-randomness3 and the ability to have hundreds of short loops was basically unique to the vinyl record format at the time. Sure, locked loops could exist on earlier formats that use similar groove-riding like wax cylinders, but it would’ve been far sillier than this already silly trio of records. While, much like Mini Disc, the concept could be replicated digitally… I don’t believe these ever saw a release outside of vinyl.


  1. This disparity has come up before and while I get it, I have to say that calling this ‘a demo, but not scene’ is the funniest fucking thing I’ve heard in a while. ↩︎
  2. Well, RRR-1000 was slightly less ambitious, with 20 artists contributing 50 grooves each. ↩︎
  3. As opposed to, say, randomly fast-forwarding a tape. ↩︎

Rediscovering Compact Cassettes

This year has been a long decade, and seeking little pleasures has been of the utmost importance. Working from home has left me with the opportunity to listen to music more often as I work. I tend not to work in the room with my turntable, so this has largely been a matter of listening from my phone. This is fine, but I know I tend to have very different listening patterns when I’m listening on my phone vs. on vinyl; particularly, I get rather caught up flipping between the same handful of tracks that are currently on my mind instead of selecting an album and listening through. While this is not always the case, it’s certainly a pattern I’ve fallen into more during this curséd year.

To this end, I’ve decided to revisit the audio format of my youth, Compact Cassettes. At the risk of sounding like an excellent Techmoan video, they sound… better than I’ve been led to remember. It feels like CD came around, and while vinyl made a nice resurgence, the Compact Cassette was banished to memories of terrible sound and mangled tape. I acquired two portable decks – an old Sanyo M5550 which still needs some work to get in ideal operating order, and a far newer Sony WM-EX633. I’ve acquired a few tapes, being far stricter with my only-buy-things-I’ll-listen-to-all-the-way-through policy that started with vinyl; I don’t plan to acquire more than the 20 or so that will fit in a yet-to-be-purchased case. Both decks sound good as far as the cassette head and circuitry, though the Sanyo is essentially unlistenable at the moment due to some speed issues. So I’ve been listening exclusively on the Sony, and it’s been a very pleasing experience. They’re both very different devices than those I owned in my youth, however, and seem worth briefly discussing.

The Sony WM-EX633

This thing is tiny, basically the size of a cassette case. One side has the door, the other has four buttons arranged in a square: play above stop; fast-forward above rewind. It’s not the easiest layout (for me, at least) to memorize; fortunately there is a guide bump on the play button. The player is servo-driven and auto reverses. While playing, the play button is also used to reverse direction manually, and holding it switches to side-repeat mode. I expected this would be track-repeat mode, as the deck does detect silence for automatic search (accessed by pressing fast-forward or rewind during play), but this oddly does not seem to be the case. Along the edges are the door release; switches for volume limiting, cassette repeat, bass boost1, and Dolby B; and of course the requisite volume knob and headphone jack (with an awkward remote port attached for good measure). A feature it lacks which I would really appreciate is an indicator of which direction the tape is being played.

Dead center of the buttons is a battery indicator which is always on, as I’m using NiMh cells in lieu of the original NiCads. The battery itself is an interesting creature – the 7/5 F6 flat “gumstick” cell. Seemingly used by nothing nowadays, yet oddly not proprietary to Sony, this slim rectangle definitely helps to keep the size of the Walkman down with a capacity somewhere between that of a AA and AAA cell. Several companies still make them, and spring-loaded adjustable smart chargers (like the Klarus K1 I’m using) will charge them fine. Additionally, a black plastic bulge can be attached to the bottom of the Walkman to allow for the use of a AA cell, but this really spoils the whole aesthetic. I honestly wish these flat cells had stuck around a bit longer, though as a general rule, I wish more stuff still used standard cells and the market had pushed harder to NiMH usage. Having to charge everything’s inbuilt LiIon cell is one of the worse bits of the modern era.

The Sanyo M5550

This is a larger deck, but smaller than its predecessor, the M4440. Yet, for 1981, it is quite small. Unlike the Sony, the Sanyo has a mechanical tape transport. While they get a bad rap for being primitive in comparison to servo-based units, but I always assumed they were much more reliable. Yet, aside from its speed issues, the transport on my Sanyo is also not in perfect order, often failing to fast forward or rewind unless the deck is playing. The machine is sturdy and heavy for its size, and having opened it up, its circuitry is packed about as tightly as I’ve ever seen. I should probably recap it at some point, but that is a terrifying prospect.

It lacks auto reverse, which I’m fine with. Like the Sony, it does have track skipping. It also has a couple of interesting features that the Sony lacks. Though handy, the most boring is a second headphone jack. Following this is a pair of user-accessible speed controls – one prominently placed on the outside for on-the-fly adjustment, the other a small pot tucked away in the battery compartment. Calibrating with a wow and flutter meter was incredibly easy thanks to this accessible pot. But the most interesting feature is the microphone – that has no ‘record’ feature to go with it. The deck has two settings that mix the feed with the tape audio. One does this exclusively for the sake of hearing the world around you as you pipe music into your ears – foretelling the ambient listening modes of modern noise cancelling earphones2. The other feature additionally subtracts the left and right channels from one another, cancelling the ‘center’ where vocals tend to be set in the mix. It is, so to speak, a personal karaoke deck.

To wrap up…

Both of these decks are pleasing objects with clever designs. I should point out that neither deck has a balance control, nor a feature that I find rather useful – a counter. I hope to get the Sanyo up to tip-top shape at some point, though I only paid a song for it so if I fail to do this it won’t be the end of the world. I am quite content with listening on the Sony, and wouldn’t hesitate to recommend getting back into the compact cassette world to anyone who wanted a compact, analog full-album listening experience.


  1. Bass boost is a feature I ignore on pretty much every piece of audio equipment I use, but it does help fill in thinness on some cassette masters. The regular ‘Megabass’ mode does this well; the ‘Groove’ mode is unlistenable. ↩︎
  2. This felt so modern to me, in fact, that I was hesitant to believe that it was the intended purpose of the function. Shout out to my friend Alex for locating an article from the time that described it in just that way. ↩︎

Super Mario Bros. 35

I go on a tangent toward the end of this post about my fear regarding preservation when Switch Online inevitably shutters. However, since posting this, I have learned that SMB35 was planned to be shut down at the end of March 2021. This is absurd, and likely warrants its own post, but it’s worth mentioning that my fears are not only warranted but grossly underestimated.

Super Mario World was likely the first smooth-scrolling platformer that I ever played, albeit briefly at a family friend’s house. Later, PC games like Jill of the Jungle and Jazz Jackrabbit were the first of the genre that I owned and played heavily. It wasn’t until a bit later in life that I got an NES and fell in love with… well, a ton of games for the system, but most relevantly the first and third Super Mario Bros. games1. The first, in particular, with its simplicity, quick plays, and the convenience of being bundled with Duck Hunt spent a lot of time in my NES. I’m not describing some special, unique experience here, of course, but I am of an age that the first Super Mario Bros. game is firmly implanted in my mind.

Nintendo recently released Super Mario Bros. 35, a 35-player online battle royale interpretation of the original. The premise is rather simple: survive (with only a single life) longer than anyone else, feeding a constantly down-ticking clock and collecting coins that can be spent to activate a random power-up. Killing an enemy will send it to whoever you are currently targeting (Tetris 99-style), and bump up your clock by a number of seconds dependent upon how you killed it. At first blush, it feels like Super Mario Bros., just with a few more Goombas here and there. Then Bloopers start flying through the sky like you’re running a randomized ROM. Because levels are selected from a pool chosen by all 35 players at the beginning, you find that your options in the first warp zone are 1-1, 1-2 (the level you’re already in), and 3-4. Things are decidedly abnormal.

Strategy, therefore, becomes very different than in vanilla Super Mario Bros. Quick platforming is less important, and coins actually mean something. Fire flowers becomes vital when your path is littered with errant Piranha Plants. Skipping things to gain a ton of time by knocking out a major line of enemies with a Koopa shell is often worth it. You can’t play it like Super Mario Bros., even though it’s so familiar.

Tetris 99 is the obvious point of comparison as far as player interaction and targeting UI. As with Tetris 99, the right stick chooses between four targeting styles: random, most coins, least time, and attacking. The left stick allows you to manually select a target. Unlike Tetris 99, this feels… minimally important, at best. Tetris is a game where you have at least some handle on a player’s current standing; you can readily see if they’re stacked up poorly or loaded up with junk blocks. In Super Mario Bros. 35, another player’s screen might, at best, give you an indication that you’re about to be hit with a Bowser. The options don’t make a ton of sense to me either. Sure, more coins means that you’ll acquire more if you KO the player, but it also means they have more up their sleeve to deal with enemies. Likewise, the player with the least time on their clock may be at a disadvantage, but you’re helping with that problem by giving them enemies to kill.

Unlike Tetris, Super Mario Bros. also tends to lull toward the end. Once there are only five players left, the clock speeds up significantly, but otherwise… there’s a lot less of a threat, simply because fewer players means fewer enemies getting tossed around. It becomes far more empty and far more like a normal game of Super Mario Bros., which is weird from a typical difficulty curve standpoint. The endgame kind of drags because of this, and you’re likely to just get hosed by the timer because of the lack of enemies. It’s not a problem, per se, it’s just a rather unusual flow.

All in all, Nintendo has done quite well to make a fresh Super Mario Bros. experience. I’ve become quite addicted to it, and hate that in a few years when they’ve released a new console and have no interest in running their Switch Online servers anymore… well it’ll all be an unpreserved memory. These unique multiplayer experiences are wonderful, especially in this year of isolation. I can’t help but think about them as deliberate ephemera, however, albeit less in a planned obsolescence sense and more in the sense of a simple lack of caring.


  1. I played a lot of Super Mario Bros. 2 as well, primarily because it was a game I could play as a lady, woo! But it never had the same appeal as 1 and 3 for me, and I find its controls rather unpleasant today. ↩︎

Replacing a fan

It’s been less than a year since I purchased my HP Spectre x360, and while I have mostly been very happy with it1, the left fan started honking and making automobile-engine-attempting-to-turn-over sounds. I probably should’ve sent it in for warranty service, but I opted to replace it myself, with only minor damage. The damage was precisely the sort of thing I predicted – I believe I snapped one of the blasted plastic clips that hold everything together these days2, and I misjudged the sort of connector that the fan uses and mangled it a bit in the process. That said, given the compact nature of the laptop and the (lack of) serviceability of machines in general these days, it was not an awful process. Six external screws, three internal on the fan, and one little bit of tricky cable management. While I’m clearly not the authority on cracking modern electronics open without damage (I grew up ripping apart retro tech, k?) I could cause far more trouble if I were to use worse tools. So while I’m motivated, I figured I’d briefly go into the tools that I currently prefer after years of curation. Note that none of this is sponsored, nor are any of the links affiliate links, &c. This is just… stuff I like.

Spudging

Step one of the process was lifting the long rubber feet up to get to the screws hidden underneath. The simplest way to do this is with a plastic pry tool, commonly known as a spudger. These came in handy when dealing with the clipped plastic as well, though… clearly I goosed that part a bit. All of these tools are pretty much created equal, but I’m quite partial to the combination of rigidity and thin edges on the Norton’s Universal Cleaning Stick. The other most useful varieties that I’ve found are the card-style and pick-style spudgers available for peanuts on AliExpress.

Screwdriving precisely

Step two was the aforementioned six external screws, and further down the line were… more screws. I have long used Vessel Megadora drivers for standard sizes; I use the thru-tang drivers primarily and have one of the Impacta impact drivers as well. I’ve used other thru-tang drivers that I think are as good, so this largely comes down to comfort. More recently, I have started flushing out my precision drivers with their metal-bodied precision drivers. These are undoubtedly the best precision drivers I’ve used. One issue that I have with many brands is that the spinny bit on the top tends to bind. Vessel’s are the smoothest I’ve used, on both their plastic (ESD-safe) precision drivers, and on their metal drivers. The metal drivers also have incredibly tight knurling that allows for a wild amount of torque if necessary, though they’re shrouded by default with a comfortable rubber grip. They make a few oddballs as well, including the pentalobe for opening up an iPhone and several tri-wings for, among other things, Nintendo products3. Their ESD-safe plastic-bodied drivers are nice as well, but the shanks are very long, and a bit unwieldy in my opinion; I have a set that I leave heavily magnetized for pick-up and screw-starting tasks. Finally, while irrelevant to this repair, they make ceramic-tipped precision drivers, one of which I always use for pot adjustment.

Sorting screws

Step two-and-a-half (?) was putting those screws somewhere. I have tried various grid boxes, which always have too few compartments, sized far too large. For a while, I used AideTek BOX-ALL SMD cases, which I still use for small screw/parts storage, but I never found something flexible enough to adapt to the various layers and components of a given project. I finally acquired SMD snap boxes from WenTai, which are individual cubes that can be snapped together in any configuration necessary. For me, this is incredibly helpful for being able to spatially lay out where screws came from. If I find that there are more screws than I initially thought, I can add a row or column and keep the spatial relationship accurate. The cubes individually close, so longer-term storage is possible. The modular nature makes them a little bit finicky, but it was worth it for the peace of mind. I initially thought there were only four screws on the exterior, so I started with a 2x2 arrangement; I added two columns when I discovered the additional two screws. I made a different arrangement for the interior screws. This was a great investment.

Dusting and grounding

Step three was blowing some dust out from the inside of the machine, which I did with a recently-acquired DataVac ESD-safe combination vacuum/blower. This vacuum is relatively light, powerful, and quieter than expected; I’ve switched away from my Dirt Devil Scorpion to the DataVac even just for household vacuuming needs. But for electronics, it is ESD-safe, and it can be used as a blower as well as a vacuum. This was also step zero, I guess – I used the grounded lug on the DataVac as a discharge point for an antistatic bracelet. It’s a great vacuum, and it’s nice knowing it won’t fry my electronics.

Miscellanea(ing)

A couple of other things came up. Despite using somewhat-awkward AAAA batteries4, the size of the Streamlight Stylus penlight is great for handling alongside another precision tool, as well as cramming into tight spots. It doesn’t use a great LED, it only has a single brightness level, but its size makes it a great tool for working on things like this.

I used a Wiha ESD-safe chip lifter as a sort of blunt, safe hook for holding a stubborn cable back as I accessed the one truly tricky screw in the project. This is not its intended purpose, but I didn’t want to use one of my sharp Pratt-Read picks and stab anything delicate. I have lifted chips with the chip-lifter, and it does this quite well; it’s just a tiny pry bar basically.

While less directly related to the project, I mentioned above having my long-shanked Vessel precision drivers magnetized; I love the compact size of the PB Swiss de/magnetizer. It usually just chills on my fridge, though it should probably be stuck to my toolbox.


  1. On the hardware side, at least. I haven’t yet made Windows bearable or set up a dual-boot. ↩︎
  2. Future bri: start at the hinge side of the panel; if you did break a clip it was up here and there isn’t much else you can damage in this area. ↩︎
  3. It took me a while to find tri-wing drivers that weren’t cheap screw-eating monsters. The first high-quality tri-wings I found were from Moody Tools, and these are great, I just… kind of prefer the Vessels as far as how they fit my hand and handle. And Moody’s spinny bits aren’t as smooth. ↩︎
  4. I’ve been using NiMH AAAA cells that appear to be branded EBL, though EBL’s site doesn’t seem to show AAAAs so I suppose they’ve either been discontinued or mine are fake. ↩︎