Legacy OSes Archive

Recently, the oldest known versions of DOS were uploaded to the internet, and Michal Necasek dove into the floppy images. Even after more than 40 years(!), old software releases and pre-releases can still surface. In the case of 86-DOS 0.11 and 0.34 it’s practically a miracle, since there were probably never very many copies in existence. For the first time since the early 1980s, FAT formatted floppies with the primordial 16-byte directory entry format have come to light. The old 16-byte directory entries were gone by 86-DOS 1.0 in April 1981 and of course never appeared in any public PC DOS release. These prehistoric versions of 86-DOS allow us to fill in further missing pieces in the puzzle of DOS origins. It is fascinating to follow how DOS developed from almost nothing to a multi-million dollar business in the course of just a few years. ↫ Michal Necasek It started out so humbly. Yet, here we are, in 2024, and variants of DOS still have their uses in certain niches. An incredible legacy, for sure.

This is the precursor to MS-DOS and is likely the oldest known version to survive. (I had previously uploaded Version 0.34, which was at the time thought to hold that honor.) ↫ Archive.org The longer we wait, the harder it’s going to be to archive and preserve software like this.

NetDrive is a DOS device driver that allows you to access a remote disk image hosted by another machine as though it was a local device with an assigned drive letter. The remote disk image can be a floppy disk image or a hard drive image. ↫ Michael B. Brutman An incredibly useful tool for modern-day DOS work.

I tried to launch BattleTech over and over and had zero success. I couldn’t figure out why it was struggling on my model 80 board, where it runs just great on 86Box. What is going on? One thing I had stumbled upon was that if I launched an ancient Infocom game in a DOS box, and then launched BattleTech it had a much higher chance of running. But this did not always equate to it working. How is launching an old COM file from the early 80’s excise the ‘devil’ of some 1988 EXE from running? As the title suggests, it’s got to do with the math coprocessor. I know I say this often, but I’m so glad people dive into these sorts of things decades later to figure out what’s going on. It makes for great reading.

This is a native port of Digital Research’s seminal 1977 operating system CP/M to the 6502. Unlike the original, it supports relocatable binaries, so allowing unmodified binaries to run on any system: this is necessary as 6502 systems tend to be much less standardised than 8080 and Z80 systems. (The systems above all load programs at different base addresses.) Currently you can cross-assemble programs from a PC, as well as a working C toolchain with llvm-mos. For native development, there’s a basic assembler, a couple of editors, and a BASIC. You need about 20kB to run the assembler at all, and of course more memory the bigger the program. The usefulness of this project is debatable, but that doesn’t make it any less cool.

When it comes to famous operating systems for the Z80 and similar Zilog processors, the first and maybe only one to come to mind is CP/M, which was even made its presence known on the dual-CPU (8502 and Z80) Commodore 128. Yet Zilog also developed its own operating system, in the form of the comprehensively titled Z80 Operating System with Relocatable Modules and I/O Management (Z80-RIO for short). With limited documentation having survived, Ralf-Peter Nerlich has set out to retain and recover what information he can on RIO and the associated Programming Language Zilog (PLZ) after working with these systems himself when they were new. Catchy name, and awesome work to try and recover as much about it as possible.

In short, no, I’m not making it up, I did make a virus back in 1990. I don’t have the source code, unfortunately, for two reasons. It was over thirty years ago. I’m a chronic hoarder, but seemingly not that chronic. The floppy discs containing the code were confiscated. No, my mum wasn’t proud, indeed she didn’t even know about this episode at the time, and still doesn’t. Not that she’d understand what a computer virus is, even if I attempted to explain it to her. What a great story.

The other day I had a pressing “need” to examine the behavior of Adaptec 154x and compatible SCSI HBAs and their DOS drivers. I found the hard way that the AHA-154xB does not work with Adaptec’s last DOS drivers from circa 1999. That includes the drivers still available for download (ASPI4DOS.SYS version 3.36), as well as the driver shipped with OEM versions of Windows 98SE (ASPI4DOS.SYS version 3.36S). The error message is far from enlightening; effectively the driver acts as if there were no HBA at all. It turns out it’s an incredibly interesting story.

About a small town’s worth of people pointed me to this on Mastodon, so here it goes: In an IMAX theater, the m130’s job is to control the quick turn reel unit, or QTRU for short. (For many years, it appears, a non-emulated m130 sat holstered in most theaters.) The QTRU’s job is to control the platters, which are those large horizontal shelves where all of a film’s many reels are stitched together, stored, and then quickly spun out to and from the projector. The IMAX 1570 projector moves film at a little under six feet per second, so it’s all happening really fast. The m130 is apparently crucial to keeping the thing humming — “PALM PILOT MUST BE ON ALL THE TIME,” reads a notice above an image of a different m130 that has since been passed around the internet — but doesn’t often need to be used. “I’ve never had to interact with the Palm Pilot,” says one person familiar with the technology. “It’s really just a status screen.” Its job is to keep the QTRU moving at a consistent speed and to help keep the film’s video in sync with its audio. This doesn’t surprise me one bit. In environments like these, if something works, and has been working reliably for decades, there’s really no reason to change any of it. This application is probably quite simple, but since there’s only a very small number of theaters out there even capable of showing 70mm film, and it doesn’t look like it’s a format on the up and up.

DESKTOP is a graphical user interface for DOS, which ones used to be a commercial shell like MS-Windows 3.0 or GEOS. However, due to the dominance of MS-Windows 95, we were forced to stop publishing the program, so it’s free now… I’ve done a lot of digging into these alternative shells for both MS-DOS and Windows 3.x/9x, but I had somehow never heard of this one. It’s freely available, and has some neat and interesting features, like copy and paste, a full file manager, and much more.

As of year 2004, Dr. Gary Kildall’s operating system called CP/M was approaching 30 years old. I decided then to describe that history on my Web site, before it was lost. I worked on that through 2008; and updated my notes since. See my DRI home page for links to Web pages about that event, and about about persons, companies and developments related to Digital Research and/or CP/M in the S-100 and microcomputer world of the 1970’s. This Web page provides some ideas about how to get and “run” CP/M today, or past alternatives to CP/M, in the 21st century. I should really set up a CP/M environment to experience what it’s like – when I first started using computers, it had already lost out to DOS.

Yes, I am playing Dope Wars on a Palm Pilot inside my iPhone. It’s thanks to The Internet Archive, which is once again launching a giant collection of software you can instantly play on any web browser, up to and including your touchscreen-equipped phone. There are currently 565 classic Palm apps in all, including games, widgets, and even free trials from both the greyscale and color eras. This is probably the easiest way to experience Palm OS applications now. I will still opt for any of my dozen or so real devices, but having so many applications safe and sound on the Archive is amazingly awesome.

Disassembly and enhancements for Apple II DeskTop (a.k.a. Mouse Desk), a “Finder”-like GUI application for 8-bit Apples and clones with 128k of memory, utilizing double hi-res monochrome graphics (560×192), an optional mouse, and the ProDOS 8 operating system. There’s a new version with tons of improvements.

But still, CP/M was, for a while, the industry-standard microcomputer OS, making Digital Research a powerful and important company. Wealthy companies that lose dominance over a market they formerly controlled don’t tend to just give up. Digital Research put a substantial R&D effort into expanding and enhancing CP/M, creating a large family of OSes. It had some significant wins and big sales. Some of those products are still in use. All those products are arguably “CP/M derivatives”, and as such, Bryan Sparks’ 2001 edict might have just open-sourced them all. One of the many giants we lost along the way.