Modern Smartphone Vs. 80s Supercomputer

March 26, 2026 by Bryan Cockfield 42 Comments

One of the most common ways of comparing the processing power of some microcontroller or older smartphone in a fantastical way was to say that they had more processing power than the Apollo Guidance Computer. While this sounds impressive on the surface, the AGC was the first integrated circuit computer ever built and is predictably under-powered by almost all modern standards. A more apt comparison would be to compare a smartphone to a supercomputer from some bygone era, and someone has recently done just that.

The linked article looks at a modern iPhone 17 compared to the Cray 2 supercomputer. When the Cray 2 was first built in the mid 80s, it was the fastest computer in the world at 1.9 GFLOPS using four vector processors. A modern iPhone is estimated to have slightly more than that, so in some ways the iPhone comes out on top.

However, the Cray 2 was built with vector processors, a specialized type of processor meant to perform rapid calculations on specific types of data sets. So the Cray 2 may have been faster at these types of tasks than the more general-purpose A19 processor, and the A19 may have the edge in other tasks.

The other major difference the article doesn’t discuss is what software runs on these computers. The Cray 2 supercomputer ran a modified version of UNIX System V, which at the time was owned by AT&T (and which ran on plenty of other computers as well). Although proprietary in some sense, it was much more open than Apple’s iOS operating system, allowing users to run whatever software they wanted to run on the supercomputers that they bought and paid for, and to modify many parts of the operating system itself. In that sense, the Cray will always maintain the edge over Apple and their walled garden.

Only Known Copy Of UNIX V4 Recovered From Tape

December 29, 2025 by Maya Posch 43 Comments

UNIX version 4 is quite special on account of being the first UNIX to be written in C instead of PDP-11 ASM, but it was also considered to have been lost to the ravages of time. Joyfully, we can report that the more than fifty year old magnetic tape that was recently discovered in a University of Utah storeroom did in fact contain the UNIX v4 source code. As reported by Tom’s Hardware, [Al Kossow] of Bitsavers did the recovery by passing the raw flux data from the tape read head through the ReadTape program to reconstruct the stored data.

Since the tape was so old there was no telling how much of the data would still be intact, but fortunately it turned out that the tape was not only largely empty, but the data that was on it was in good nick. You can find the recovered files here, along with a README, with Archive.org hosting the multi-GB raw tape data. The recovered data includes the tape file in SimH format and the filesystem

Suffice it to say that you will not run UNIX v4 on anything other than a PDP-11 system or emulated equivalent, but if you want to run its modern successors in the form of BSD Unix, you can always give FreeBSD a shot.

Have They Found A Complete UNIX V4?

November 9, 2025 by Jenny List 19 Comments

If you’ve ever combed boxes of old tech detritus in search of a nugget of pure gold, we know you’ll appreciate the excitement of discovering, in a dusty University of Utah storeroom, a tape labelled “UNIX Original from Bell Labs V4 (See manual for format)”. If the tape contains what’s promised on the label, this is a missing piece of computer history, because no complete copies of this version are known to exist.

The tape will be delivered by hand to the Computer History Museum, where we hope its contents will be safely retrieved for archive and analysis. The reporter of the find, research professor [Rob Ricci], identifies the handwriting as that of Jay Lepreau, someone whose word on which UNIX version it contained could, we hope, be trusted.

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UNIX For A Legacy TI

September 26, 2025 by Bryan Cockfield 14 Comments

Although now mostly known as a company who cornered the market on graphing calculators while only updating them once a decade or so, there was a time when Texas Instruments was a major force in the computing world. In the late 70s and early 80s they released a line of computers called the TI-99 to compete (unsuccessfully) with various offerings from Commodore, and these machines were fairly robust for the time. They did have limited memory but offered a 16-bit CPU and plenty of peripherals, and now there’s even a UNIX-like OS that they can run.

This version of UNIX is called UNIX99 and is the brainchild of AtariAge forum member [mrvan] who originally wasn’t looking to develop a full operating system for this computer but rather a set of standard C libraries to help with other projects. Apparently the step from that to a UNIX-flavored OS wasn’t too big so this project was born. While the operating system doesn’t have a UNIX certification, it has most of the tools any of us would recognize on similar machines. The OS has support for most of the TI-99 hardware, file management, a basic user account system, and a command shell through which scripts can be written and executed.

That being said, the limitations of the hardware do come through in the operating system. There’s no multitasking, for example, and the small amount of memory is a major hurdle as well. But that’s what makes this project all the more impressive, and [mrvan] isn’t stopping here. He’s working on a few other improvements to this platform, and we look forward to seeing future releases. UNIX itself is extremely influential in the computing world, and has been used a the model for other homebrew UNIX-like operating systems on similar platforms of this era such as the Z80.

Thanks to [Stephen] for the tip!

Photo courtesy of Rama & Musée Bolo via Wikimedia Commons

FPGA Brings UNIX V1 To The DEC J-11

August 30, 2025 by Bryan Cockfield 13 Comments

If you’ve never used a PDP-11 before it’s probably because you simply weren’t around in the 70s and 80s. Although they started as expensive machines only in research labs and industry, they eventually became much more accessible. They’re a bit of a landmark in computing history, too, being largely responsible for the development of things like UNIX and the C programming language. [ryomuk] is using an FPGA in combination with an original DEC J-11 to bring us a new take on this machine. (Google Translate from Japanese)

The FPGA used in this build is a Tang Nano 20k, notable for its relatively low cost. The FPGA emulates the memory system and UART of a PDP-11 system down to the instruction set, while the original, unmodified DEC chip is left to its own devices. After some initial testing [ryomuk] built a PC11 paper tape emulator to ensure the system was working which runs a version of BASIC from the era. The next thing up was to emulate some disk drives and co-processors so that the machine can run the first version of UNIX.

[ryomuk] also developed a PCB for the DEC microprocessor and the FPGA to sit on together, and it includes all of the jumpers and wiring needed to allow the computer to run UNIX, as well as handling other miscellaneous tasks like power. It’s an interesting build that gets to the heart of the early days of computer science. PDP-11 computers did eventually get smaller and more accessible, and if you want to build a modern version this build fits a complete system into an ATX case.

Thanks to [RetepV] for the tip!

The Epochalypse: It’s Y2K, But 38 Years Later

July 22, 2025 by Lewin Day 44 Comments

Picture this: it’s January 19th, 2038, at exactly 03:14:07 UTC. Somewhere in a data center, a Unix system quietly ticks over its internal clock counter one more time. But instead of moving forward to 03:14:08, something strange happens. The system suddenly thinks it’s December 13th, 1901. Chaos ensues.

Welcome to the Year 2038 problem. It goes by a number of other fun names—the Unix Millennium Bug, the Epochalypse, or Y2K38. It’s another example of a fundamental computing limit that requires major human intervention to fix.

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Switching From Desktop Linux To FreeBSD

June 29, 2025 by Maya Posch 45 Comments

People have been talking about switching from Windows to Linux since the 1990s, but in the world of open-source operating systems, there is much more variety than just the hundreds of flavors of Linux-based operating systems today. Take FreeBSD, for example. In a recent [GNULectures] video, we get to see a user’s attempt to switch from desktop Linux to desktop FreeBSD.

The interesting thing here is that both are similar and yet very different, mainly owing to their very different histories, with FreeBSD being a direct derivative of the original UNIX and its BSD derivative. One of the most significant differences is probably that Linux is just a kernel, with (usually) the GNU/Hurd userland glued on top of it to create GNU/Linux. GNU and BSD userland are similar, and yet different, with varying levels of POSIX support. This effectively means that FreeBSD is a singular OS with rather nice documentation (the FreeBSD handbook).

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