MS-DOS

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Classic PC game emulation is back on the iPhone with iDOS 3 release

App Store, Apple, DOS games, emulator, gaming, iDOS, iDOS 3, MS-DOS, Tech / /

Emulation —

Apple amended its App Store rules to allow PC emulators, not just console ones.

–

An MS-DOS command line prompt showing the C drive

Enlarge / The start of any journey in MS-DOS.

Samuel Axon

After a 14-year journey of various states of availability and usefulness amid the shifting policies of Apple’s App Store approval process, MS-DOS game emulator iDOS is back on the iPhone and iPad. It’s hopefully here to stay this time.

iDOS allows you to run applications made for MS-DOS via DOSBox, with a nice retro-styled interface. Its main use case is definitely playing DOS games, but it has seen a rocky road to get to this point. Initially released over a decade ago, it existed quietly for its niche audience, though it saw some changes that made it more or less useful in the developer’s quest to avoid removal from the App Store after it violated Apple’s rules. That culminated in it being removed altogether in 2021 after some tweets and articles brought attention to it.

But earlier this year, Apple made big changes to its App Store rules, officially allowing “retro game emulators” for the first time. That cleared the way for a wave of working console game emulators like Delta and RetroArch, which mostly work as you might expect them to on any other platform now. But when iDOS developer Chaoji Li and other purveyors of classic PC emulator software attempted to do the same for old PC games for MS-DOS and other non-console computing platforms, they were stymied. Apple told them that it didn’t consider their apps to be retro game console emulators and that they violated rules intended to prevent people from circumventing the App Store by running applications from other sources.

PC emulator UTM released a version of its software that worked around Apple’s rules, but it was a subpar experience. But on August 2, Apple amended its App Store rules to explicitly allow emulators of classic PC games. That opened the door for iDOS, which has made its triumphant return and works quite well.

Developer Chaoji Li’s announcement of iDOS 3’s availability didn’t have a tone of triumph to it, though—more like exhaustion, given the app’s struggles over the years:

It has been a long wait for common sense to prevail within Apple. As much as I want to celebrate, I still can’t help being a little bit cautious about the future. Are we good from now on?

Get iDOS3 on AppStore

I hope iDOS can now enjoy its turn to stay and grow.

P.S. Even though words feel inadequate at times, I would like to say thank you to the supporters of iDOS. In many ways, you keep iDOS alive.

Given that Apple’s policy changes were driven by regulatory concerns, it seems likely it’ll stick this time, but after everything that’s happened, you can’t blame Li for putting a question mark on this.

In any case, if you’re among the dozens (or maybe several hundred) of people looking to play Commander Keen, Might and Magic: The World of Xeen, Wolfenstein 3D, or Jill of the Jungle on your iPhone, today is your day.

Classic PC game emulation is back on the iPhone with iDOS 3 release Read More »

a-few-weeks-with-the-pocket-386,-an-early-‘90s-style,-half-busted-retro-pc

A few weeks with the Pocket 386, an early-‘90s-style, half-busted retro PC

80386, book 8088, Features, intel, MS-DOS, pocket 386, Retro computing, Tech, windows 95 / /
The Pocket 386 is fun for a while, but the shortcomings and the broken stuff start to wear on you after a while.

Enlarge / The Pocket 386 is fun for a while, but the shortcomings and the broken stuff start to wear on you after a while.

Andrew Cunningham

The Book 8088 was a neat experiment, but as a clone of the original IBM PC, it was pretty limited in what it could do. Early MS-DOS apps and games worked fine, and the very first Windows versions ran… technically. Just not the later ones that could actually run Windows software.

The Pocket 386 laptop is a lot like the Book 8088, but fast-forwarded to the next huge evolution in the PC’s development. Intel’s 80386 processors not only jumped from 16-bit operation to 32-bit, but they implemented different memory modes that could take advantage of many megabytes of memory while maintaining compatibility with apps that only recognized the first 640KB.

Expanded software compatibility makes this one more appealing to retro-computing enthusiasts since (like a vintage 386) it will do just about everything an 8088 can do, with the added benefit of a whole lot more speed and much better compatibility with seminal versions of Windows. It’s much more convenient to have all this hardware squeezed into a little laptop than in a big, clunky vintage desktop with slowly dying capacitors in it.

But as with the Book 8088, there are implementation problems. Some of them are dealbreakers. The Pocket 386 is still an interesting curio, but some of what’s broken makes it too unreliable and frustrating to really be usable as a vintage system once the novelty wears off.

The 80386

A close-up of the Pocket 386's tiny keyboard.

Enlarge / A close-up of the Pocket 386’s tiny keyboard.

Andrew Cunningham

When we talked about the Book 8088, most of our discussion revolved around a single PC: the 1981 IBM PC 5150, the original machine from which a wave of “IBM compatibles” and the modern PC industry sprung. Restricted to 1MB of RAM and 16-bit applications—most of which could only access the first 640KB of memory—the limits of an 8088-based PC mean there are only so many operating systems and applications you can realistically run.

The 80386 is seven years newer than the original 8086, and it’s capable of a whole lot more. The CPU came with many upgrades over the 8086 and 80286, but there are three that are particularly relevant for us: for one, it’s a 32-bit processor capable of addressing up to 4GB of RAM (strictly in theory, for vintage software). It introduced a much-improved “protected mode” that allowed for improved multitasking and the use of virtual memory. And it also included a so-called virtual 8086 mode, which could run multiple “real mode” MS-DOS applications simultaneously from within an operating system running in protected mode.

The result is a chip that is backward-compatible with the vast majority of software that could run on an 8088- or 8086-based PC—notwithstanding certain games or apps written specifically for the old IBM PC’s 4.77 MHz clock speed or other quirks particular to its hardware—but with the power necessary to credibly run some operating systems with graphical user interfaces.

Moving on to the Pocket 386’s specific implementation of the CPU, this is an 80386SX, the weaker of the two 386 variants. You might recall that the Intel 8088 CPU was still a 16-bit processor internally, but it used an 8-bit external bus to cut down on costs, retaining software compatibility with the 8086 but reducing the speed of communication between the CPU and other components in the system. The 386SX is the same way—like the more powerful 80386DX, it remained a 32-bit processor internally, capable of running 32-bit software. But it was connected to the rest of the system by a 16-bit external bus, which limited its performance. The amount of RAM it could address was also limited to 16MB.

(This DX/SX split is the source of some confusion; in the 486 generation, the DX suffix was used to denote a chip with a built-in floating-point unit, while 486SX processors didn’t include one. Both 386 variants still required a separate FPU for people who wanted one, the Intel 80387.)

While the Book 8088 uses vintage PC processors (usually a NEC V20, a pin-compatible 8088 upgrade), the Pocket 386 is using a slightly different version of the 80386SX core that wouldn’t have appeared in actual consumer PCs. Manufactured by a company called Ali, the M6117C is a late-’90s version of the 386SX core combined with a chipset intended for embedded systems rather than consumer PCs.

A few weeks with the Pocket 386, an early-‘90s-style, half-busted retro PC Read More »

30-years-later,-freedos-is-still-keeping-the-dream-of-the-command-prompt-alive

30 years later, FreeDOS is still keeping the dream of the command prompt alive

Features, freedos, MS-DOS, Tech / /
Preparing to install the floppy disk edition of FreeDOS 1.3 in a virtual machine.

Enlarge / Preparing to install the floppy disk edition of FreeDOS 1.3 in a virtual machine.

Andrew Cunningham

Two big things happened in the world of text-based disk operating systems in June 1994.

The first is that Microsoft released MS-DOS version 6.22, the last version of its long-running operating system that would be sold to consumers as a standalone product. MS-DOS would continue to evolve for a few years after this, but only as an increasingly invisible loading mechanism for Windows.

The second was that a developer named Jim Hall wrote a post announcing something called “PD-DOS.” Unhappy with Windows 3.x and unexcited by the project we would come to know as Windows 95, Hall wanted to break ground on a new “public domain” version of DOS that could keep the traditional command-line interface alive as most of the world left it behind for more user-friendly but resource-intensive graphical user interfaces.

PD-DOS would soon be renamed FreeDOS, and 30 years and many contributions later, it stands as the last MS-DOS-compatible operating system still under active development.

While it’s not really usable as a standalone modern operating system in the Internet age—among other things, DOS is not really innately aware of “the Internet” as a concept—FreeDOS still has an important place in today’s computing firmament. It’s there for people who need to run legacy applications on modern systems, whether it’s running inside of a virtual machine or directly on the hardware; it’s also the best way to get an actively maintained DOS offshoot running on legacy hardware going as far back as the original IBM PC and its Intel 8088 CPU.

To mark FreeDOS’ 20th anniversary in 2014, we talked with Hall and other FreeDOS maintainers about its continued relevance, the legacy of DOS, and the developers’ since-abandoned plans to add ambitious modern features like multitasking and built-in networking support (we also tried, earnestly but with mixed success, to do a modern day’s work using only FreeDOS). The world of MS-DOS-compatible operating systems moves slowly enough that most of this information is still relevant; FreeDOS was at version 1.1 back in 2014, and it’s on version 1.3 now.

For the 30th anniversary, we’ve checked in with Hall again about how the last decade or so has treated the FreeDOS project, why it’s still important, and how it continues to draw new users into the fold. We also talked, strange as it might seem, about what the future might hold for this inherently backward-looking operating system.

FreeDOS is still kicking, even as hardware evolves beyond it

Running AsEasyAs, a Lotus 1-2-3-compatible spreadsheet program, in FreeDOS.

Running AsEasyAs, a Lotus 1-2-3-compatible spreadsheet program, in FreeDOS.

Jim Hall

If the last decade hasn’t ushered in The Year of FreeDOS On The Desktop, Hall says that interest in and usage of the operating system has stayed fairly level since 2014. The difference is that, as time has gone on, more users are encountering FreeDOS as their first DOS-compatible operating system, not as an updated take on Microsoft and IBM’s dusty old ’80s- and ’90s-era software.

“Compared to about 10 years ago, I’d say the interest level in FreeDOS is about the same,” Hall told Ars in an email interview. “Our developer community has remained about the same over that time, I think. And judging by the emails that people send me to ask questions, or the new folks I see asking questions on our freedos-user or freedos-devel email lists, or the people talking about FreeDOS on the Facebook group and other forums, I’d say there are still about the same number of people who are participating in the FreeDOS community in some way.”

“I get a lot of questions around September and October from people who ask, basically, ‘I installed FreeDOS, but I don’t know how to use it. What do I do?’ And I think these people learned about FreeDOS in a university computer science course and wanted to learn more about it—or maybe they are already working somewhere and they read an article about it, never heard of this “DOS” thing before, and wanted to try it out. Either way, I think more folks in the user community are learning about “DOS” at the same time they are learning about FreeDOS.”

30 years later, FreeDOS is still keeping the dream of the command prompt alive Read More »

$200-ish-laptop-with-a-386-and-8mb-of-ram-is-a-modern-take-on-the-windows-3.1-era

$200-ish laptop with a 386 and 8MB of RAM is a modern take on the Windows 3.1 era

MS-DOS, Tech, windows 3.1, windows 95 / /

blast from the slightly more recent past —

Pocket 386 supports external accessories and will just barely run Windows 95.

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  • The Pocket 386, a new-old laptop that can run MS-DOS, Windows 3.x, and (technically) Windows 95.

    DZT’s Store

  • The Pocket 386 isn’t sleek, but it’s a lot smaller than an actual 386 laptop would be.

    DZT’s Store

  • The system in clear, plus the included dongles for adding external ports.

    DZT’s store

Of the many oddities you can buy from Aliexpress, some of the weirdest are the recreations of retro computer systems in semi-modern designs. We’re most intimately familiar with the Book 8088, a recreation of the original 1981 IBM PC inside a chunky clamshell laptop. The people behind the Book 8088 are also responsible for the Hand386, which is a bit like a late-80s PC stuck inside an old Palm Pilot or Blackberry, and a second revision of the Book 8088 with more built-in ports and a VGA-capable graphics adapter installed instead of a basic CGA adapter.

Whoever is selling these systems is now back with the Pocket 386, which combines Hand386-style internals with a clamshell design similar to the Book 8088. The result is the kind of IBM-compatible system that would have been common during the Windows 3.1 era, when MS-DOS still dominated (especially for games) but Windows was on the upswing.

The heart of the laptop isn’t a genuine retro 386 but an Ali M6117 embedded processor. This is a newer chip that integrates a 40 MHz 80386SX CPU core along with an ALi M1217B chipset. The system also includes 8MB of RAM, one of three different replaceable VGA adapters (either a Cirrus Logic CL-GD542X, a TVGA9000i, or a CHIPS F655x5), a Yamaha OPL3 sound card, an 800×480 IPS display panel, a 4,000 mAh battery, and a CompactFlash slot for storage. There’s no built-in trackpad, though the arrow keys can be used to simulate a mouse. The system also includes a USB port, though as with the Book 8088, it may be usable for mass storage but not for typical USB accessories.

The Pocket 386 supports standard ports like PS/2 and VGA via a number of custom ports and external dongles.

Enlarge / The Pocket 386 supports standard ports like PS/2 and VGA via a number of custom ports and external dongles.

DZT’s Store

For accessories, the laptop includes a few ports on the back that can be attached to external dongles; included dongles can be used to add PS/2, VGA, parallel, and serial ports to the system. The Pocket 386 is available in both a semi-translucent black finish and a clear finish, and though its normal list price is $300, it’s currently listed for $187. An adapter for adding external ISA expansion cards is sold separately.

This system could technically run Windows 95, and the seller will send you a working Windows 95 disk image (in the GHO format used by the ancient Norton Ghost backup and restore software, so you’ll need to figure that out). The Pocket 386 is just over the minimum requirements for Windows 95, which wanted a 20 MHz 386DX processor or better and at least 4MB of RAM. But even running off of a CompactFlash card instead of an ancient spinning HDD, expect Windows 95 support to be slow at best, particularly because of the technically inferior 386SX processor and the still-pretty-scanty 8MB of memory.

This system will work best if you stick to Windows 3.x and MS-DOS, though the extra CPU speed and RAM will make it infinitely more useful for retro apps and games than the Book 8088 running the same MS-DOS and early Windows software.

Listing image by DZT’s store

$200-ish laptop with a 386 and 8MB of RAM is a modern take on the Windows 3.1 era Read More »

microsoft-open-sources-infamously-weird,-ram-hungry-ms-dos-4.00-release

Microsoft open-sources infamously weird, RAM-hungry MS-DOS 4.00 release

MS-DOS, Open Source, Tech / /

a road not traveled —

DOS 4.00 was supposed to add multitasking to the OS, but it was not to be.

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A DOS prompt.

Enlarge / A DOS prompt.

Microsoft has open-sourced another bit of computing history this week: The company teamed up with IBM to release the source code of 1988’s MS-DOS 4.00, a version better known for its unpopularity, bugginess, and convoluted development history than its utility as a computer operating system.

The MS-DOS 4.00 code is available on Microsoft’s MS-DOS GitHub page along with versions 1.25 and 2.0, which Microsoft open-sourced in cooperation with the Computer History Museum back in 2014. All open-source versions of DOS have been released under the MIT License.

Initially, MS-DOS 4.00 was slated to include new multitasking features that allow software to run in the background. This release of DOS, also sometimes called “MT-DOS” or “Mutitasking MS-DOS” to distinguish it from other releases, was only released through a few European PC OEMs and never as a standalone retail product.

The source code Microsoft released this week is not for that multitasking version of DOS 4.00, and Microsoft’s Open Source Programs Office was “unable to find the full source code” for MT-DOS when it went to look. Rather, Microsoft and IBM have released the source code for a totally separate version of DOS 4.00, primarily developed by IBM to add more features to the existing non-multitasking version of DOS that ran on most IBM PCs and PC clones of the day.

Microsoft never returned to its multitasking DOS idea in subsequent releases. Multitasking would become the purview of graphical operating systems like Windows and OS/2, while MS-DOS versions 5.x and 6.x continued with the old one-app-at-a-time model of earlier releases.

Microsoft has released some documentation and binary files for MT-DOS and “may update this release if more is discovered.” The company credits English researcher Connor “Starfrost” Hyde for shaking all of this source code loose as part of an ongoing examination of MT-DOS that he is documenting on his website. Hyde has posted many screenshots of a 1984-era build of MT-DOS, including of the “session manager” that it used to track and switch between running applications.

Confidential copies of the obscure, abandoned multitasking-capable version of MS-DOS 4.00. Microsoft has been unable to locate source code for this release, sometimes referred to as

Confidential copies of the obscure, abandoned multitasking-capable version of MS-DOS 4.00. Microsoft has been unable to locate source code for this release, sometimes referred to as “MT-DOS” or “Multitasking MS-DOS.”

Microsoft

The publicly released version of MS-DOS 4.00 is known less for its new features than for its high memory usage; the 4.00 release could consume as much as 92KB of RAM, way up from the roughly 56KB used by MS-DOS 3.31, and the 4.01 release reduced this to about 86KB. The later MS-DOS 5.0 and 6.0 releases maxed out at 72 or 73KB, and even IBM’s PC DOS 2000 only wanted around 64KB.

These RAM numbers would be rounding errors on any modern computer, but in the days when RAM was pricey, systems maxed out at 640KB, and virtual memory wasn’t a thing, such a huge jump in system requirements was a big deal. Today’s retro-computing enthusiasts still tend to skip over MS-DOS 4.00, recommending either 3.31 for its lower memory usage or later versions for their expanded feature sets.

Microsoft has open-sourced some other legacy code over the years, including those older MS-DOS versions, Word for Windows 1.1a, 1983-era GW-BASIC, and the original Windows File Manager. While most of these have been released in their original forms without any updates or changes, the Windows File Manager is actually actively maintained. It was initially just changed enough to run natively on modern 64-bit and Arm PCs running Windows 10 and 11, but it’s been updated with new fixes and features as recently as March 2024.

The release of the MS-DOS 4.0 code isn’t the only new thing that DOS historians have gotten their hands on this year. One of the earliest known versions of 86-DOS, the software that Microsoft would buy and turn into the operating system for the original IBM PC, was discovered and uploaded to the Internet Archive in January. An early version of the abandoned Microsoft-developed version of OS/2 was also unearthed in March.

Microsoft open-sources infamously weird, RAM-hungry MS-DOS 4.00 release Read More »

unreleased-preview-of-microsoft’s-os/2-2.0-is-a-glimpse-down-a-road-not-taken

Unreleased preview of Microsoft’s OS/2 2.0 is a glimpse down a road not taken

ibm, microsoft, MS-DOS, OS/2, Tech / /

OS/2 the future —

Microsoft’s involvement in IBM’s OS/2 project ended before v2.0 was released.

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This big, weathered box contains an oddball piece of PC history: one of the last builds of IBM's OS/2 that Microsoft worked on before pivoting all of its attention to Windows.

Enlarge / This big, weathered box contains an oddball piece of PC history: one of the last builds of IBM’s OS/2 that Microsoft worked on before pivoting all of its attention to Windows.

In the annals of PC history, IBM’s OS/2 represents a road not taken. Developed in the waning days of IBM’s partnership with Microsoft—the same partnership that had given us a decade or so of MS-DOS and PC-DOS—OS/2 was meant to improve on areas where DOS was falling short on modern systems. Better memory management, multitasking capabilities, and a usable GUI were all among the features introduced in version 1.x.

But Microsoft was frustrated with some of IBM’s goals and demands, and the company continued to develop an operating system called Windows on its own. Where IBM wanted OS/2 to be used mainly to boost IBM-made PCs and designed it around the limitations of Intel’s 80286 CPU, Windows was being created with the booming market for PC-compatible clones in mind. Windows 1.x and 2.x failed to make much of a dent, but 1990’s Windows 3.0 was a hit, and it came preinstalled on many consumer PCs; Microsoft and IBM broke off their partnership shortly afterward, making OS/2 version 1.2 the last one publicly released and sold with Microsoft’s involvement.

But Microsoft had done a lot of work on version 2.0 of OS/2 at the same time as it was developing Windows. It was far enough along that preview screenshots appeared in PC Magazine, and early builds were shipped to developers who could pay for them, but it was never formally released to the public.

But software archaeologist Neozeed recently published a stable internal preview of Microsoft’s OS/2 2.0 to the Internet Archive, along with working virtual machine disk images for VMware and 86Box. The preview, bought by Brian Ledbetter on eBay for $650 plus $15.26 in shipping, dates to July 1990 and would have cost developers who wanted it a whopping $2,600. A lot to pay for a version of an operating system that would never see the light of day!

The Microsoft-developed build of OS/2 2.0 bears only a passing resemblance to the 32-bit version of OS/2 2.0 that IBM finally shipped on its own in April 1992. Neozeed has published a more thorough exploration of Microsoft’s version, digging around in its guts and getting some early Windows software running (the ability to run DOS and Windows apps was simultaneously a selling point of OS/2 and a reason for developers not to create OS/2-specific apps, one of the things that helped to doom OS/2 in the end). It’s a fascinating detail from a turning point in the history of the PC as we know it today, but as a usable desktop operating system, it leaves something to be desired.

All 26 disks of the OS/2 2.0 preview, plus hefty documentation manuals. There are some things about the '90s I don't miss.

Enlarge / All 26 disks of the OS/2 2.0 preview, plus hefty documentation manuals. There are some things about the ’90s I don’t miss.

This unreleased Microsoft-developed OS/2 build isn’t the first piece of Microsoft-related software history that has been excavated in the last few months. In January, an Internet Archive user discovered and uploaded an early build of 86-DOS, the software that Microsoft bought and turned into MS-DOS/PC-DOS for the original IBM PC 5150. Funnily enough, these unreleased previews serve as bookends for IBM and Microsoft’s often-contentious partnership.

As part of the “divorce settlement” between Microsoft and IBM, IBM would take over the development and maintenance of OS/2 1.x and 2.x while Microsoft continued to work on a more advanced far-future version 3.0 of OS/2. This operating system was never released as OS/2, but it would eventually become Windows NT, Microsoft’s more stable business-centric version of Windows. Windows NT merged with the consumer versions of Windows in the early 2000s with Windows 2000 and Windows XP, and those versions gradually evolved into Windows as we know it today.

It has been 18 years since IBM formally discontinued its last release of OS/2, but as so often happens in computing, the software has found a way to live on. ArcaOS is a semi-modernized, intermittently updated branch of OS/2 updated to run on modern hardware while still supporting the ability to run MS-DOS and 16-bit Windows apps.

Unreleased preview of Microsoft’s OS/2 2.0 is a glimpse down a road not taken Read More »

the-oldest-known-version-of-ms-dos’s-predecessor-has-been-discovered-and-uploaded

The oldest-known version of MS-DOS’s predecessor has been discovered and uploaded

86-dos, IBM PC, microsoft, MS-DOS, pc-dos, retrocomputing, Tech / /

a new doscovery —

86-DOS would later be bought by Microsoft and take over the computing world.

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The IBM PC 5150.

Enlarge / The IBM PC 5150.

SSPL/Getty Images

Microsoft’s MS-DOS (and its IBM-branded counterpart, PC DOS) eventually became software juggernauts, powering the vast majority of PCs throughout the ’80s and serving as the underpinnings of Windows throughout the ’90s.

But the software had humble beginnings, as we’ve detailed in our history of the IBM PC and elsewhere. It began in mid-1980 as QDOS, or “Quick and Dirty Operating System,” the work of developer Tim Paterson at a company called Seattle Computer Products (SCP). It was later renamed 86-DOS, after the Intel 8086 processor, and this was the version that Microsoft licensed and eventually purchased.

Last week, Internet Archive user f15sim discovered and uploaded a new-old version of 86-DOS to the Internet Archive. Version 0.1-C of 86-DOS is available for download here and can be run using the SIMH emulator; before this, the earliest extant version of 86-DOS was version 0.34, also uploaded by f15sim.

This version of 86-DOS is rudimentary even by the standards of early-’80s-era DOS builds and includes just a handful of utilities, a text-based chess game, and documentation for said chess game. But as early as it is, it remains essentially recognizable as the DOS that would go on to take over the entire PC business. If you’re just interested in screenshots, some have been posted by user NTDEV on the site that used to be Twitter.

According to the version history available on Wikipedia, this build of 86-DOS would date back to roughly August of 1980, shortly after it lost the “QDOS” moniker. By late 1980, SCP was sharing version 0.3x of the software with Microsoft, and by early 1981, it was being developed as the primary operating system of the then-secret IBM Personal Computer. By the middle of 1981, roughly a year after 86-DOS began life as QDOS, Microsoft had purchased the software outright and renamed it MS-DOS.

Microsoft and IBM continued to co-develop MS-DOS for many years; the version IBM licensed and sold on its PCs was called PC DOS, though for most of their history the two products were identical. Microsoft also retained the ability to license the software to other computer manufacturers as MS-DOS, which contributed to the rise of a market of mostly interoperable PC clones. The PC market as we know it today still more or less resembles the PC-compatible market of the mid-to-late 1980s, albeit with dramatically faster and more capable components.

The oldest-known version of MS-DOS’s predecessor has been discovered and uploaded Read More »