386

14 Articles

Reject Modernity, Return To 80s, Learn C.

July 10, 2026 by 108 Comments

We’re not exactly sure how old [SnailMail] is, but he’s probably a member of Generation Alpha considering that to our wizened eyes the lad looks only slightly older than a fetus– which makes it all the more impressive that he’s written his own text editor, from scratch, in C– on a 386. See, [SnailMail] tried to learn the modern way, with IDEs that have code completion and AI integration, but his thoughts couldn’t gel in the modern environment. So he went online and bought an old IBM-compatible complete with monochrome amber monitor, and a whole 4MB of RAM. Big spender that he is, [SnailMail] upgraded that to 8MB.

Rather than fall victim to the siren song of Wolfenstien 3D or SimCity, he set out to learn to code: C, specifically, since that language bridges four decades between [SnailMail] and his new PC. Even more specifically, he got ahold of disks for Borland Turbo C and Turbo C++, which brings back memories for some of us. Of course the lad also had to learn how to use a DOS PC at the same time, but a teen in the 80s with a fresh box would have climbed the same steep learning curve. Some of you probably remember doing so yourselves. Just like you–or the hypothetical teen in the 80s–[SnailMail] did it not by googling or begging Claude for answers, but by digging into books. Many books.

After all the reading, he started with a text editor, something we remember being a pretty big project not given to first year students. Video evidence suggests he pulled it off. He describes how his solution works from about 8:00 in the video, so you greybeards in the audience can judge his work for yourself.

If you’re a member of Gen Alpha reading this and looking to learn to program, we cannot recommend this technique highly enough– [SnailMail] is going to have a better understanding of the underlying logic of computer science than a lot of CS grads being frocked today. Especially when you consider he ends by promising to learn assembly, something we heartily endorse.

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HamsterOS Crams Complete Graphical Desktop Onto 1.44 MB Floppy

June 29, 2026 by 45 Comments

It’s not every day that there’s a new OS in the works for 386 and 486-era hardware, but [John Swiderski] let us know he working hard to bring HamsterOS to retrocomputing enthusiasts everywhere.

HamsterOS targets a November 2026 release.

HamsterOS is a tiny but full-featured multitasking 32-bit graphical operating system that fits on a single 1.44 MB floppy disk. It’s designed as a floppy-first OS, but can easily be installed to a hard drive and includes a suite of native applications. There’s even DOS support!

The list of features is impressive, many of which are targeted at making life a little easier for those working with vintage hardware. One example we like is the CMOS crash counter, which automatically forces the system into a basic VGA safe mode after three consecutive failed boot attempts.

Speaking of making vintage computing a little easier to handle, [John] also released HamsterWeazle, a free GUI front-end for Greaseweazle, the open-source USB device that makes interfacing to old floppy drives easy. If you’re finding yourself intrigued by software like HamsterOS but wondering how you’d write to a 1.44 MB floppy without already having some old hardware up and running, Greaseweazle over USB — and HamsterWeazle to make it much more user-friendly — is one way you’d do it.

We recently featured GentleOS, a charming and streamlined graphical OS aimed at vintage hardware that makes a point of showing what’s possible when new ideas meet old hardware. If you have a retrocomputing project you want to show off, custom OS or otherwise, let us know on our tips line!

Restoring A 3DO Blaster Card From The Early 90s

May 15, 2026 by 12 Comments

Before the modern trifecta of video game giants came to dominate the market around two decades ago, the world was awash in video game consoles. Many of these retro platforms have largely been forgotten outside of the enthusiast communities, and an average gamer today might not have ever heard of brands like ColecoVision or TurboGrafx. Among these unusual, rare, or forgotten systems was the 3DO which wasn’t strictly a console but rather a specification that manufacturers could use to make consoles on their own. But even more unusual was that this standard could be used to build 3DO-compatible expansion cards for PCs as well.

In this video, [The Retro Collective] received one of these boards to add to their museum, but like much retro hardware of this era it wasn’t working exactly like it would have out-of-the-box. After adding it to one of their period-correct 386 machines of the time, they found that it would only work properly with weight applied at one of the corners. This led to the discovery of some disconnected pins on the PCB, and a repair of that and some other issues brought the card back to life again.

The video also discusses the platform itself and shows how it would connect to a PC from that time. The PC would have needed a Sound Blaster card, a CD ROM drive with a particular proprietary interface, and a few other hardware requirements, but with everything up and working the player would have a console that theoretically competed with the original Playstation or Nintendo 64. It also illustrates an alternative path video games might have taken where expansion cards added console compatibility to any modern PC, but unfortunately the 3DO never really caught on.

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Unusual Circuits In The Intel 386’s Standard Cell Logic

November 25, 2025 by 7 Comments

Intel’s 386 CPU is notable for being its first x86 CPU to use so-called standard cell logic, which swapped the taping out of individual transistors with wiring up standardized functional blocks. This way you only have to define specific gate types, latches and so on, after which a description of these blocks can be parsed and assembled by a computer into elements of a functioning application-specific integrated circuit (ASIC). This is standard procedure today with register-transfer level (RTL) descriptions being placed and routed for either an FPGA or ASIC target.

That said, [Ken Shirriff] found a few surprises in the 386’s die, some of which threw him for a loop. An intrinsic part of standard cells is that they’re arranged in rows and columns, with data channels between them where signal paths can be routed. The surprise here was finding a stray PMOS transistor right in the midst of one such data channel, which [Ken] speculates is a bug fix for one of the multiplexers. Back then regenerating the layout would have been rather expensive, so a manual fix like this would have made perfect sense. Consider it a bodge wire for ASICs.

Another oddity was an inverter that wasn’t an inverter, which turned out to be just two separate NMOS and PMOS transistors that looked to be wired up as an inverter, but seemed to actually there as part of a multiplexer. As it turns out, it’s hard to determine sometimes whether transistors are connected in these die teardowns, or whether there’s a gap between them, or just an artifact of the light or the etching process.

Tiny386 On An Espressif ESP32-S3

November 13, 2025 by 14 Comments

Some people may remember the joys of trying to boot Linux on an 8-bit AVR microcontroller, which was an absolute exercise in patience. In comparison [He Chunhui]’s Tiny386 emulator running on an ESP32-S3 MCU is positively zippy when it boots and runs Windows 95. The provided video (also embedded below) makes clear that while you can comfortably waddle off to prepare and pour a fresh cup of tea, it’s actually borderline usable.

The source code can be obtained via GitHub, which contains not just the basic emulated 80386 CPU written in C99, but also peripherals borrowed from TinyEMU and QEMU, along with a SeaBIOS ROM. In addition to the Windows 95 demo it’s claimed that Tiny386 should be able to run most 16/32-bit software.

Right now the ESP32-S3 version targets the JC3248W535 board, which is a roughly $30 development board featuring a built-in display with touch screen and an ESP32-S3 module. Although it has a USB-C port, it appears that this one is just for programming and not for the USB peripheral of the ESP32-S3. With the USB OTG peripheral used, one could conceivably make a small 386 system based around an ESP32-S3 that features a USB hub to plug a keyboard, mouse, etc. into.

Considering that the Tiny386 emulator is a very simple and straightforward approach to emulating an early-90s PC, some optimization might enable a pretty zippy general purpose PC for early 90s software. Quite a boost from watching Linux struggle into a command line on an AVR, indeed.

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How Intel’s 386 Protects Itself From ESD, Latch-up And Metastability

August 21, 2025 by 11 Comments

To connect the miniature world of integrated circuits like a CPU with the outside world, a number of physical connections have to be made. Although this may seem straightforward, these I/O pads form a major risk to the chip’s functioning and integrity, in the form of electrostatic discharge (ESD), a type of short-circuit called a latch-up and metastability through factors like noise. Shielding the delicate ASIC from the cruel outside world is the task of the I/O circuitry, with [Ken Shirriff] recently taking an in-depth look at this circuity in Intel’s 386 CPU.

The 386 die, zooming in on some of the bond pad circuits. (Credit: Ken Shirriff)
The 386 die, zooming in on some of the bond pad circuits. (Credit: Ken Shirriff)

The 386 has a total of 141 of these I/O pads, each connected to a pin on the packaging with a delicate golden bond wire. ESD is on the top of the list of potential risks, as a surge of high voltage can literally blow a hole in the circuitry. The protective circuit for this can be seen in the above die shot, with its clamping diodes, current-limiting resistor and a third diode.

Latch-up is the second major issue, caused by the inadvertent creation of parasitic structures underneath the P- and NMOS transistors. These parasitic transistors are normally inactive, but if activated they can cause latch-up which best case causes a momentary failure, but worst case melts a part of the chip due to high currents.

To prevent I/O pads from triggering latch-up, the 386 implements ‘guard rings’ that should block unwanted current flow. Finally there is metastability, which as the name suggests isn’t necessarily harmful, but can seriously mess with the operation of the chip which expects clean binary signals. On the 386 two flip-flops per I/O pad are used to mostly resolve this.

Although the 386’s 1985-era circuitry was very chonky by today’s standards, it was still no match for these external influences, making it clear just how important these protective measures are for today’s ASICs with much smaller feature sizes.

How Corroded Can A Motherboard Be?

December 5, 2024 by 9 Comments

We will admit it. If we found a 386 motherboard as badly corroded as the one [Bits und Bolts] did, we would trash it—not him, though. In fact, we were surprised when he showed it and said he had already removed most of it in vinegar. You can check the board out in the video below.

There was still a lot of work to do on both the front and back of the board. The motherboard was a Biostar and while it isn’t as dense as a modern board, it still had plenty of surface mount parts jammed in.

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