Usagi’s PDP-11 Supercomputer And Appeal For Floating Point Systems Info

January 12, 2025 by 22 Comments

With an exciting new year of retrocomputing ahead for [David Lovett] over at the Usagi Electric YouTube channel, recently some new hardware arrived at the farm. Specifically hardware from a company called Floating Point Systems (FPS), whose systems provide computing features to assist e.g. a minicomputer like [David]’s PDP-11/44 system with floating point operations. The goal here is to use a stack of 1980s-era FPS hardware to give the PDP-11/44 MIMD (multiple instructions, multiple data) computing features, which is a characteristic associated with supercomputers.

The FPS hardware is unfortunately both somewhat rare and not too much documentation, including schematics, has been found so far. This is where [David] would love some help from the community on finding more FPS hardware, documentation and any related information so that it can all be preserved.

FPS itself was acquired by Cray in 1991, before SGI took over Cray Research in 1996. As is usual with such acquisitions, a lot of older information tends to get lost, along with the hardware as it gets tossed out over the years by companies and others. So far [David] has acquired an FPS-100 array processor, an interface card for the PDP-11 and an FPS-3000, the latter of which appears to be a MIMD unit akin to the FPS-5000.

Without schematics, let alone significant documentation, it’s going to be an uphill battle to make it all work again, but with a bit of help from us retrocomputer enthusiasts, perhaps this might not be as impossible after all.

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Blinkenlights-First Retrocomputer Design

January 11, 2025 by 10 Comments

[Boz] wants to build a retrocomputer, but where to start? You could start with the computery bits, like say the CPU or the bus architecture, but where’s the fun in that? Instead, [Boz] built a righteous blinkenlights array.

What’s cool about this display is that it’s ready to go out of the box. All of the LEDs are reverse-mount and assembled by the board maker. The 19″ 2U PCBs serve as the front plates, so [Boz] was careful not to use any through-hole parts, which also simplified the PCB assembly, of course. Each slice has its own microcontroller and a few shift registers to get the bits lit up, and that’s all there is to it. They take incoming data at 9600 baud and output blinkiness.

Right now it pulls out its bytes from his NAS. We’re not sure which bytes, and we think we see some counters in there. Anyway, it doesn’t matter because it’s so pretty. And maybe someday the prettiness will lure [Boz] into building a retrocomputer to go under it. But honestly, we’d just relax and watch the blinking lights.

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Stacy’s Computer Has Got It Going On

January 5, 2025 by 14 Comments

According to [ClassicHasClass], the best way to open an Atari Stacy is to not open an Atari Stacy. Apparently, these old computers were not pleasant to work on. The cables were not keyed and were prone to short against things. Screws easily strip out plastic holes. Of course, there wouldn’t be a story if there wasn’t a teardown and an upgrade that you can check out in the post.

The Stacy was one of Atari’s earliest portable systems and the first ST portable (that is, STacy). There’s a backlit LCD, a keyboard and trackball, and the usual ports. You could make do with a single floppy or spring for a second floppy or an internal SCSI hard drive. The 8 MHz 68000-based machine would set you back north of $2,300 back in 1989.

The original plan was to run the thing on C-cell batteries, but that would give you about 15 minutes of operation. They finally decided it was a luggable — you’d have to plug it into the wall. The battery compartment was there, but empty and glued shut.

Apparently, there were about 35,000 of these made, but they seem somewhat rare. But we do like a rare retrocomputer. Or even some that aren’t so rare.

Keeping Track Of Old Computer Manuals With The Manx Catalog

December 24, 2024 by 4 Comments

An unfortunate reality of pre-1990s computer systems is that any manuals and documentation that came with them likely only existed on paper. That’s not to say there aren’t scanned-in (PDF) copies of those documents floating around, but with few of these scans being indexable by search engines like Google and Duck Duck Go, they can be rather tricky to find. That’s where the Manx catalog website seeks to make life easier. According to its stats, it knows about 22,060 manuals (9,992 online) across 61 websites, with a focus on minicomputers and mainframes.

The code behind Manx is GPL 2.0 licensed and available on GitHub, which is where any issues can be filed too. While not a new project by any stretch of the imagination, it’s yet another useful tool to find a non-OCR-ed scan of the programming or user manual for an obscure system. As noted in a recent Hacker News thread, the ‘online’ part of the above listed statistics means that for manuals where no online copy is known, you get a placeholder message. Using the Bitsavers website along with Archive.org may still be the most pertinent way to hunt down that elusive manual, with the Manx website recommending 1000bit for microcomputer manuals.

Have you used the Manx catalog, or any of the other archiving websites? What have been your experiences with them? Let us know in the comments.

The Last Acorn BBC Computer Wasn’t A BBC Micro

December 17, 2024 by 27 Comments

For home computer users, the end of the 1980s was the era of 16-bit computers. The challenge facing manufacturers of 8-bit machines through the middle of the decade was to transfer their range and customers to the new hardware, and the different brands each did this in their own way. Commodore and Atari had 68000-based powerhouses, and Apple had their 16-bit-upgraded IIGS for the middle ground below the Mac, but what about Acorn, makers of the BBC Micro? They had the Archimedes, and [RetroBytes] takes us through how they packaged their 32-bit ARM processor for consumers.

The A3000 was the computer you wanted if you were a geeky British kid at the end of that decade, even if an Amiga or an ST was what you got. Schools had bought a few of the desktop Archimedes’, so if you were lucky you’d got to know Arthur and then RiscOS, so you knew just how fast these things were compared to the competition. The video below the break takes a dive into the decisions behind the design of this first ARM consumer product, and along the way it explains a few things we didn’t know at the time.  We all know what happened to Acorn through the 1990s and we all use ARM processors today, so it’s a fascinating watch. If only an extra two hundred quid had been in the kitty back then and we could have bought one ourselves.

If you have never used an Archimedes you can get pretty close today with another Cambridge-designed and ARM-powered computer. RiscOS never went away, and you can run it on a Raspberry Pi. As we found, it’s still pretty useful.

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Retro Computer Goes Back To The 1950s

December 6, 2024 by 24 Comments

When thinking of retrocomputing, many of us will imagine machines such as the Commodore 64 or Apple II. These computers were very popular and have plenty of parts and documentation available. Fewer will go back to the Intel 8008 or even 4004 era which were the first integrated circuit chips commercially available. But before even those transistor-based computers is a retrocomputing era rarely touched on: the era of programmable vacuum tube machines. [Mike] has gone back to the 1950s with this computer which uses vacuum tubes instead of transistors.

The computer has an eight-bit architecture and features most of the components of any modern transistor-based computer of similar computational ability. Memory, I/O, an arithmetic logic unit including a carry bit that allows it to do 16-bit arithmetic, are all implemented using 6N3P dual triode tubes that date to the 50s and 60s and would have been used in similar computers like the IBM 700. All of this drives a flight simulator program or a Fibonacci number generator, demonstrating its general purpose computing capabilities.

Of course, tubes were generally phased out in favor of transistors largely due to their power and space requirements; [Mike] needs a stepladder to maintain this computer as well as around ten minutes each time he starts it up to allow the tubes to warm up, with each module needing over three amps of current each. It’s a hugely impressive build and we’d recommend checking out the video linked below to get more details on its operation. If you’re looking for something a little more accessible to get into the world of vacuum tubes, this single-board tube computer fits the bill.

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Ampere WS-1: The Other APL Portable Computer

December 6, 2024 by 10 Comments

When thinking of home computers and their portable kin it’s easy to assume that all of them provided BASIC as their interpreter, but for a while APL also played a role. The most quaint APL portable system here might be the Ampere WS-1, called the BIG.APL. Released in Japan in November of 1985, it was a very modern Motorola M68000-based portable with fascinating styling and many expansion options. Yet amidst an onslaught of BASIC-based microcomputers and IBM’s slow retreat out of the APL-based luggables market with its IBM 5110, an APL-only portable in 1985 was a daring choice.

Rather than offering both APL and BASIC as IBM’s offerings had, the WS-1 offered only APL, with a custom operating system (called Big.DOS) which also provided a limited a form of multi-tasking involving a back- and foreground task. Running off rechargeable NiCd batteries it could power the system for eight hours, including the 25 x 80 character LCD screen and the built-in microcassette storage.

Although never released in the US, it was sold in Japan, Australia and the UK, as can be seen from the advertisements on the above linked Computer Ads from the Past article. Clearly the WS-1 never made that much of a splash, but its manufacturer seems to be still around today, which implies that it wasn’t a total bust. You also got to admit that the design is very unique, which is one of the reasons why this system has become a collector’s item today.