Open the case on a Microkey Primo and go looking for the video chip. Go on. Take your time. There isn’t one. Every pixel of that 256 by 192 picture comes out of the same Z80 clone that’s also meant to be running your BASIC program, and somehow this thing still worked well enough to teach an entire generation of Hungarian schoolkids to type. That’s either an insult to the word “computer” or one of the more honest pieces of cost engineering I’ve had on this bench in a while. It’s the second one. Stay with me.
The chip that isn’t there
Strip away the case and the story is minimalism, the enforced kind rather than the fashionable kind. The CPU is a U880, VEB Mikroelektronik’s unlicensed East German clone of the Zilog Z80, clocked at a fairly ordinary 2.5 MHz. There’s no ULA, no video controller, no sound chip beyond a single one-bit speaker the manual calls “the horn” with a straight face I have to respect. Sixteen kilobytes of ROM. RAM in three tiers, up to 48K, with a 6-kilobyte frame buffer sitting at the top of it and, more interestingly, room for a second buffer as well, so the machine could flip between two screens without visibly redrawing one over the other.
Generating a coherent 256 by 192 monochrome picture entirely off a general-purpose CPU, with no helper silicon doing the timing-critical work, is a genuinely difficult trick. The processor has to hit its memory reads for the display at exactly the right moment on every single scan line while still finding cycles left over to run your program, and get the arithmetic wrong and you get a picture that tears itself apart. Whoever at SZTAKI worked out that timing budget earned every forint they weren’t paid for it. Compare it to what it was actually up against: a ZX Spectrum owner had the identical 256 by 192 pixels on their own screen, running off a proper ULA that Sinclair could at least buy in volume, with colour attributes the Primo simply never had the silicon to attempt. Same resolution, wildly different amount of custom hardware doing the work to get there. The Primo did it with less because less was the entire brief.
A keyboard that fought back
Now the part of the review where the engineering stops being clever and starts being a genuine liability. Gábor Örley, tasked with a keyboard in a country that couldn’t reliably source mechanical switches, built a capacitive touch panel straight onto the motherboard. Copper traces under the case, no moving parts, nothing to wear out in forty years. I’ll give it this much: as an engineering answer to a components shortage, it’s inventive. As a thing you’re expected to type BASIC on for an hour, it’s a genuine failure.
There’s no key travel and no tactile feedback, so you’re pressing your fingertip flat against a plate and hoping the sensitivity’s calibrated right that week. Owners nicknamed it “tapi pad” (“the tap-board”) and, with more feeling, “masszír pad” (“the massage-board”). Sensitivity drift meant characters would occasionally repeat themselves with your finger nowhere near the key, which is the one failure mode a keyboard is specifically supposed to never have. SZTAKI’s own Series B swapped it for real push-button switches and fixed the entire complaint in one revision, which tells you the flat panel was never actually necessary. It was a components-shortage workaround wearing the costume of a design decision, and about a thousand Series B units out of a run of roughly seven to nine thousand ever got the fix.
The “grill oven” that ate the budget
Then there’s the power supply, and here my cynicism finally has somewhere honest to land, because this one isn’t a components shortage, it’s a plain design miscalculation. The external PSU, originally saddled with the working name Energoter before somebody mercifully renamed it, ran hot enough that Hungarian owners called it the “grill oven.” A heavy transformer, real heat off the case and a retail price that landed the whole package at around 10,000 forint against an average monthly wage of roughly 5,500. That’s most of two months’ pay for a machine whose own manufacturer had reportedly been aiming for half that.
You can forgive an under-resourced state institute for not having a Z80 fab. You can’t as easily forgive a PSU that runs hot enough to earn a nickname and expensive enough to blow the original price target on its own. That’s not the embargo talking. That’s a bill of materials nobody signed off properly.
The machine that beat the room and still lost the order
The frustrating part of this whole story is that when SZTAKI’s engineers were given a proper run at fixing their own mistakes, they did it, and it still didn’t matter. The Pro/Primo, built for the second national School Computer Tender, dropped the capacitive keyboard for a real mechanical keybed using magnets instead of springs, added a colour graphics card running 32 shades out of a 256-colour palette, and rebuilt the memory around fewer, denser RAM chips. Every complaint on this review’s charge sheet, answered. It placed first in the tender’s judging.
Schools still bought Commodore’s C16 instead, at 8,775 forint against the Pro/Primo’s 17,000. Around fifty Pro/Primo units got built. None were ever sold as a product. A machine that beat the field on merit lost the actual sale on arithmetic, and no amount of clever chip-count reduction fixes a bill nearly double the competition’s.
Verdict
As a piece of “make it work with what’s actually on the shelf” engineering, the Primo deserves real respect: a full monochrome display generated off a bare CPU, a double-buffered frame layout, and a genuinely creative (if genuinely miserable) answer to a switch shortage nobody in Hungary could solve by wishing harder. As a product somebody was expected to buy, price it and support, it was let down twice over: once by a keyboard that should never have shipped in its first form, and once by a PSU that cost more to run than the machine it was powering deserved. The engineers did their job. Whoever signed off the Energoter and the retail price didn’t do theirs, and the schoolchildren of Hungary typed their first line of BASIC on the difference.
