I bought another four-function calculator

Something I find rather amusing is that despite my owning… a lot of classic HP calculators1, this here blog only has posts about one old Sinclair calculator (which is, at least, a postfix machine) and one modern four-function, single-step Casio calculator (that somehow costs $300). And, as of today… yet another modern Casio calculator. I actually do want to write something about the HPs at some point, but… they’re well-known and well-loved. I’m excited about this Casio because it’s a weird throwback (that, like the S100, I had to import), and because it intersects two of my collector focuses: calculators and retro video games.

The mid-1970s brought mass production of several LCD technologies, which meant that pocket LCD calculators (and even early handheld video game consoles were a readily obtainable thing by the early 1980s. Handheld video games were in their infancy, and seeking inspiration from calculators seemed to be a running theme. Mattel’s Auto Race came to fruition out of a desire to reuse readily-available calculator-sized LED technology in the 1970s; Gunpei Yokoi was supposedly inspired to merge games with watches (in, of course, the Game & Watch series) after watching someone fiddle idly with a calculator. Casio took a pretty direct approach with this, releasing a series of calculators with games built in. Later games had screens with both normal calculator readouts and custom-shaped electrodes to present primitive graphics (like the Game & Watch units, or all those old terrible Tiger handhelds), some of which were rather large for renditions of games like Pachinko. The first, however, was essentially a bog-standard calculator as far as hardware was concerned2: regular 8-digit 7-segment display, regular keypad. I suspect this was largely to test the reception of the format before committing to anything larger; aside from the keypad graphics, the addition of the speaker, and the ROM mask… it looks like everything could’ve been lifted off of the production line for any number of their calculators: the LC-310 and LC-827 have identical layouts.

This was the MG-880, and it was clearly enough of a hit to demonstrate the viability of pocket calculators with dedicated game modes. The game itself is simple. Numbers come in from the right side of the screen in a line. The player is also represented by a number, which they increment by pressing the decimal separator/aim key. When the player presses the plus/fire key, the closest matching digit is destroyed. These enemy numbers come in ever-faster waves, and once they collide with you, it’s game over. Liquid Crystal has more information on the MG-880 here.

So that’s all very interesting (if you’re the same type of nerd I am), but I mentioned I was going to be talking about a modern Casio calculator in this post. About three years ago, Casio decided to essentially rerelease (remaster?) the MG-880 in a modern case; this is the SL-880. I haven’t owned an MG-880 before, so I can’t say that the game is perfectly recreated down to timing and randomization and what-have-you, but based on what I’ve read/seen of the original, it’s as faithful a recreation as one needs. In fact, while the calculator has been upgraded to ten digits, the game remains confined to the MG-880’s classic eight. Other upgrades to the calculator side of things include dual-power, backspace, negation, memory clear, tax rate functions (common on modern Japanese calculators) and square root3. You can also turn off the in-game beeping, which was not possible on the MG-880. The SL-880 is missing one thing from its predecessor, however: the melody mode. In addition to game mode, the speaker allowed for a melody mode where different keys simply mapped to different notes. The only disappointing thing about this omission is how charming it is seeing the solfège printed above the keys.

So was the SL-880 worth importing? Honestly, yes. The calculator itself feels impossibly light and a bit cheap, but it is… a calculator that isn’t the S100 in the year 2020. The game holds up better than I expected. It is, of course, still a game where you furiously mash two keys as numbers appear on a screen, but given the limitations? Casio made a pretty decent calculator game in 1980. More important to me, however, is where it sits in video game history. One might say I should just seek out an original MG-880 for that purpose, and… perhaps I will, some day4. But I think there’s something special about Casio deciding to release a throwback edition of such an interesting moment in video game history. And while the MG-880 was a success, it certainly isn’t as much of a pop culture icon as, say, the NES. This relative obscurity is likely why I find this much more charming than rereleases like the NES Classic Edition. It feels like Casio largely made it not to appeal to collectors, but to commemorate their own history.


  1. Because they are the best. ↩︎
  2. I assume the timing for the game relied on the processor clock, but I do wonder if there’s a separate crystal for this purpose. ↩︎
  3. The calculators that are largely physically identical to the MG-880 all have square root functions. Casio had to omit a button in order to add the game/melody button, but I wonder if square root was partially chosen to free up ROM space. I have my doubts given the time period, but the thought lingers. ↩︎
  4. I’d likely get any of their other calculator games from the 1980s at this point. I have the game part of the MG-880, and the collector part is more in the concept of “1980’s Casio calculator game” than the MG-880 specifically. ↩︎