Running Stock MS-DOS On A Modern ThinkPad

It might seem like the days of MS-DOS were a lifetime ago because…well, they basically were. Version 6.22 of the venerable operating system, the last standalone release, came out back in 1994. That makes even the most recent version officially 30 years old. A lot has changed in the computing world since that time, so naturally trying to run such an ancient OS on even a half-way modern machine would be a waste of time. Right?

As it turns out, getting MS-DOS 6.22 running on a modern computer isn’t nearly as hard as you’d think. In fact, it works pretty much perfectly. Assuming, that is, you pick the right machine. [Yeo Kheng Meng] recently wrote in to share his experiments with running the final DOS release on his Intel-powered ThinkPad X13 from 2020, and the results are surprising to say the least.

To be clear, we’re not talking about some patched version of DOS here. There’s no emulator at work either. Granted [Yeo] did embrace a few modern conveniences, such as using a USB floppy drive emulator to load the disk images instead of fiddling with actual floppies, and installing DOS onto an external drive so as not to clobber his actual OS on the internal NVME drive. But other than that, the installation of DOS on the ThinkPad went along just as it would have in the 1990s.

Continue reading “Running Stock MS-DOS On A Modern ThinkPad”

Microsoft Updates MS-DOS GitHub Repo To 4.0

We’re not 100% sure which phase of Microsoft’s “Embrace, Extend, and Extinguish” gameplan this represents, but just yesterday the Redmond software giant decided to grace us with the source code for MS-DOS v4.0.

To be clear, the GitHub repository itself has been around for several years, and previously contained the source and binaries for MS-DOS v1.25 and v2.0 under the MIT license. This latest update adds the source code for v4.0 (no binaries this time), which originally hit the market back in 1988. We can’t help but notice that DOS v3.0 didn’t get invited to the party — perhaps it was decided that it wasn’t historically significant enough to include.

That said, readers with sufficiently gray beards may recall that DOS 4.0 wasn’t particularly well received back in the day. It was the sort of thing where you either stuck with something in the 3.x line if you had older hardware, or waited it out and jumped to the greatly improved v5 when it was released. Modern equivalents would probably be the response to Windows Vista, Windows 8, and maybe even Windows 11. Hey, at least Microsoft keeps some things consistent.

It’s interesting that they would preserve what’s arguably the least popular version of MS-DOS in this way, but then again there’s something to be said for having a historical record on what not to do for future generations. If you’re waiting to take a look at what was under the hood in the final MS-DOS 6.22 release, sit tight. At this rate we should be seeing it sometime in the 2030s.

Hackaday Links Column Banner

Hackaday Links: February 11, 2024

Apple’s Vision Pro augmented reality goggles made a big splash in the news this week, and try as we might to resist the urge to dunk on them, early adopters spotted in the wild are making it way too easy. Granted, we’re not sure how many of these people are actually early adopters as opposed to paid influencers, but there was still quite a bit of silliness to be had, most of it on X/Twitter. We’d love to say that peak idiocy was achieved by those who showed themselves behind the wheels of their Teslas while wearing their goggles, with one aiming for an early adopter perfecta, but alas, most of these stories appear to be at least partially contrived. Some people were spotted doing their best to get themselves killed, others were content to just look foolish, especially since we’ve heard that the virtual keyboard is currently too slow for anything but hunt-and-peck typing, which Casey Niestat seemed to confirm with his field testing. After seeing all this, we’re still unsure why someone would strap $4,000 worth of peripheral-vision-restricting and easily fenced hardware to their heads, but hey — different strokes. And for those of you wondering why these things are so expensive, we’ve got you covered.

Continue reading “Hackaday Links: February 11, 2024”

Breaking Through The 1 MB Barrier In DOS With Unreal Mode And More

The memory map of the original 8086 computer with its base and extended memory made the original PC rather straightforward, but also posed countless issues for DOS-based applications as they tried to make use of memory beyond the legacy 1 MB address space. The initial ways to deal with this like EMS, XMS and UMB were rather cumbersome and often impractical, but with the arrival of the 80286 and 80386 processors more options opened up, including protected mode. More interestingly, this led to unreal mode, DOS extenders and the somewhat more obscure LOADALL instruction, as covered by [Julio Merino] in a new article.

This article builds on the first one which covered the older methods and covered the basics of protected mode. Where protected mode is convenient compared to real mode is that with the former the memory accesses go via the MMU and thus allows for access to 16 MB on the 80286 and 4 GB on the 80386. The segment descriptors and resolving of these that make this possible can be (ab)used on the 80286 and up by realizing that these segment descriptors are also used in real mode. Unreal mode is thus about switching to protected mode, loading arbitrary segment descriptors and switching back to real mode. As this is outside the original processor spec, it is commonly called ‘unreal mode’.

Continue reading “Breaking Through The 1 MB Barrier In DOS With Unreal Mode And More”

Hackaday Links Column Banner

Hackaday Links: January 7, 2024

Oh, perfect — now our cars can BSOD. At least that’s how it looks from a forum post showing a Blue Screen of Death on a Ford Mustang Mach E, warning that an over-the-air software update failed, and now the car can’t be driven. The BSOD includes a phone number to reach Ford’s Customer Relationship Center and even presents a wall of text with specific instructions to the wrecker driver for loading the bricked vehicle onto a flatbed. Forum users questioned the photo’s veracity, but there are reports of other drivers getting bricked the same way. And we’ve got to point out that even though this specific bricking happened to an EV, it could just have easily happened to an ICE vehicle too; forum members were particularly prickly about that point. It would be nice if OTA software updates on vehicles could always roll back to the previous driveable state. Still, we suppose that’s not always possible, especially if memory gets corrupted during the update. Maybe the best defense against a bricked vehicle would be to keep a beater around that doesn’t need updates to keep running.

Continue reading “Hackaday Links: January 7, 2024”

Video And Audio Playback On Low-End MS-DOS Machines

For most people the phrases ‘MS-DOS’ and ‘video playback’ probably aren’t commonly associated, yet it was quite normal as those of us who were watching full-motion video with games like Command & Conquer can attest to. These audiovisual experiences did however require somewhat more capable hardware than something like an original, 4.77 MHz IBM PC. More recently, however, the removal of these limitations has been turned into a challenge that has been gleefully accepted by hackers, including [Scali] whose recent tinkering with getting not only real-time video but also audio working on these old beasts has been documented on their blog.

Unlike existing early video formats like FLIC from the 1990s, the XDC format developed over the past years enables real-time, 60 FPS video and audio playback on an 8088 IBM PC that has a SoundBlaster 2 and CGA card installed. As [Scali] notes, the SB2 card is convenient, because it enables DMA transports for the audio data, which saves a lot of precious CPU cycles. Unlike the original SB card, it also fixes some teething issues, but an SB2 is hardly ‘low-end’ for an early 1980s PC, so it has to go.

Continue reading “Video And Audio Playback On Low-End MS-DOS Machines”

Wandering Through Old Word Processors Yields A Beast

The world once ran on hardcopy, and when the digital age started to bring new tools and ways of doing things, documents were ripe for change. Today, word processors and digital documents are so ubiquitous that they are hardly worth a thought, but that didn’t happen all at once. [Cathode Ray Dude] has a soft spot for old word processors and the journey they took over decades, and he walks through the Olivetti ETV 2700.

In the days of character displays and no multitasking, WYSIWYG as a concept was still a long ways off.

The ETV 2700 is a monstrous machine; a fusion of old-school word processor, x86-based hardware, and electric 17 inch-wide typewriter.

With it one could boot up a word processor that is nothing like the WYSIWYG of today, write and edit a document, and upon command, the typewriter portion could electronically type out a page. A bit like a printer, but it really is an electric typewriter with a computer interface. Characters were hammered out one at a time with daisy wheel and ink ribbon on a manually-loaded page using all the usual typewriter controls.

While internally the machine has an x86 processor, expects a monitor and even boots MS-DOS, the keyboard had its own layout (and even proprietary keys and functions), did not support graphical output, and in other ways was unusual even by the standards of the oddball decades during which designers and products experimented with figuring out what worked best in terms of functionality and usability.

Nowadays, we see AI-enabled typewriter projects and porting vintage OSes to vintage word processor hardware, but such projects are in some part possible in part thanks to the durability of these devices. The entire video is embedded below, but you can jump directly to what the Olivetti ETV 2700 looked like on the inside if that’s what interests you most.

Continue reading “Wandering Through Old Word Processors Yields A Beast”