Fixing A C64 With A Cheap $20 Oscilloscope

September 28, 2023 by Lewin Day 16 Comments

Modern computers are so fast and complex that we would seldom try and fix them on a component level with simple DIY tools. Working on an early 1980s computer is much easier by comparison, with the fastest signals often in the single-MHz range. [Sayaka] demonstrates this by using a cheap $20 oscilloscope to troubleshoot and repair a Commodore 64.

After powering it up for the first time, the C64 displays a BASIC prompt, but none of the keys seem to work. [Sayaka] did what good hackers do, and immediately disassembled it to try and figure out the problem, suspecting the CIA chip as a likely culprit.

[Sayaka] elected to purchase a cheap DS0138 oscilloscope kit to help troubleshoot the C64. It’s not the most capable thing, with a bandwidth of just 200 KHz, but it’s enough to do some work on an old retro machine. After probing around to check a number of signals, she noted that the CIA’s pins seemed to be very oxidized and suffering poor conductivity. All it took from there was a resolder job, and the computer was repaired.

We’ve seen other cheap scopes with altogether more impressive specs, too. Video after the break. Continue reading “Fixing A C64 With A Cheap $20 Oscilloscope” →

Linux On A Commodore 64

August 27, 2023 by Al Williams 31 Comments

We are used to seeing Linux running on almost everything, but we were a bit taken aback to see [semu-c64] running Linux on a Commodore 64. But between the checked-out user name and the caveat that: “it runs extremely slowly and it needs a RAM Expansion Unit”, one can already start piecing together what’s happening here.

The machine running Linux is really a RISC-V32. It just so happens that the CPU is virtual, with the C64 pretending it is a bigger machine. The boot-up appears to take hours, so this is in no way practical, even though the comment is that optimization might be able to get a 10X speed up. It would still be about as slow as you can imagine.

To further add a layer of abstraction, the code hasn’t run yet on real Commodore hardware. Instead, it is running on an emulator. The emulator has “warp” mode to run faster than a real machine, and it is still slow. So think about that before you rush out to volunteer to boot this on your real hardware.

Tricks like this fall into the talking dog category. If a dog can talk, it isn’t that you think it will have something important to say. You just marvel that it can do it at all. Still, we get it. We spend a lot of time doing things at least as pointless. But at least it is fun!

Maybe emulate the whole thing in VR? Or maybe write some virtualization code for the C64 so you can emulate a Linux box and a quantum computer simultaneously.

Commodore 64 Web Server Brings 8-Bit Into The Future

June 1, 2023 by Lewin Day 28 Comments

These days, most webservers are big hefty rackmount rigs with roaring fans in giant datacenters. [naDDan]’s webserver is altogether more humble, as it runs on a single Commodore 64.

The C64 is running Contiki OS, an operating system for 6502-based computers. It’s built with an eye to networking, requiring ethernet hardware for full functionality. In [naDDan]’s case, he’s outfitted his C64 with an ETFE network adapter in the cartridge port to get it online. It serves up the HTML file off a 1541C floppy drive, with the drive buzzing away every time someone loads up the page.

The page itself is simple, showing some basic information on a simple blue background. There is some scrolling text though, as is befitting the 8-bit era. It’s also available in four languages.

[naDDan’s] server can be found here, according to his video, but at the time of writing, it was down for the count. Whether that’s due to a dynamic DNS issue or the simple fact that an 8-bit 6502 isn’t up to heavy traffic is up for debate. Regardless, try for yourself and see how you go. Video after the break.

Read Comic Books On The Commodore 64 With StripStream

April 20, 2023 by Lewin Day 3 Comments

Comic books are traditionally printed on paper, either as regular saddle-bound issues or in hardcover compilations. If you wanted to read them on a low-resolution screen run by an 8-bit computer, you were usually out of luck. Until now! Enter StripStream, the comic book reader for the Commodore 64.

StripStream runs on a stock PAL C64 system, using the Datasette interface. A PC program is used to compose a comic into a suitable format for the C64. It then generates a .TAP file which can either be played in a C64 emulator, or recorded onto an audio tape for loading on real hardware.

According to [janderogee], who created the software, just 34 minutes of tape can store over 300 images and 1200 lines of subtitle text. Cassettes were chosen for the storage method as standard 5 1/2″ C64 disks could only hold 165 kilobytes of data per side, meaning two whole double-sided disks would be needed to store the same amount of data. Plus, the linear nature of tape makes sense for a sequentially-read comic story. Just don’t get any ideas about doing a choose-your-adventure thing here, as StripStream isn’t built for random access.

If you don’t want to read regular comics, you can always use a tool to automatically generate them from existing media. Incidentally, StripStream is a great name, but we would have called it Comicdore 64.

Continue reading “Read Comic Books On The Commodore 64 With StripStream” →

BBS Builder Is A Framework For Running Your Own PETSCII Paradise

February 16, 2023 by Lewin Day 13 Comments

The 80s and 90s were the glory days of the BBS. The plain old telephone system was responsible for bringing us connection to other digital beings, along with plenty of spuriously-obtained software and inappropriate ASCII art. [Francesco Sblendorio] has created BBS Builder to harken back to this great era, allowing people to build their own BBSs as they see fit!

BBS Builder consists of basic classes for construction a BBS that operates in PETSCII mode. If that’s unfamiliar to you, it’s the character encoding created by Commodore, also known as CBM ASCII. BBSs created through this software can be accessed by a variety of appropriately 80s machines. The Github page outlines how to create a basic BBS using the code that can be customized to your own liking.

[Francesco] notes the system is compatible with Commodore 64s running RR-NET compatible network cards, WiFi modem cards, and 1541Ultimate hardware using UltimateTerm. Various other methods are supported too, as well as PCs and Macs running Syncterm.

Running a BBS was like running your own website back in the day. With that said, they also had a distinct community flair that is somehow missing from today’s web. Be sure to sound off with your favorite BBS in the comments!

Hackaday Links: October 30, 2022

October 30, 2022 by Dan Maloney 7 Comments

Sad news for kids and adults alike as Lego announces the end of the Mindstorms line. The much-wish-listed line of robotics construction toys will be discontinued by the end of this year, nearly a quarter-century after its 1998 introduction, while support for the mobile apps will continue for another couple of years. It’s probably fair to say that Mindstorms launched an entire generation of engineering careers, as it provided a way to quickly prototype ideas that would have been difficult to realize without the snap-fit parts and easily programmed controllers. For our money, that ability to rapidly move from idea to working model was perhaps the strongest argument for using Mindstorms, since it prevented that loss of momentum that so often kills projects. That was before the maker movement, though, and now that servos and microcontrollers are only an Amazon order away and custom plastic structural elements can pop off a 3D printer in a couple of hours, we can see how Mindstorms might no longer be profitable. So maybe it’s a good day to drag out the Mindstorms, or even just that big box of Lego parts, and just sit on the carpet and make something.

Continue reading “Hackaday Links: October 30, 2022” →

C64 Turned Theremin With A Handful Of Parts

August 30, 2022 by Lewin Day 7 Comments

The theremin is popular for its eerie sound output and its non-contact playing style. While they’re typically built using analog hardware, [Linus Åkesson] decided to make one using the venerable Commodore 64.

The instrument works by measuring the capacitance between its two antennas and the Earth. As these capacitances are changed by a human waving their hands around near the respective pitch and volume antennas, the theremin responds by changing the pitch and volume of its output.

In this case, the humble 555 is pressed into service. It runs as an oscillator, with its frequency varying depending on the user’s hand position. There’s one each for pitch and volume, naturally, using a clamp and spoon as antennas. The C64 then reads the frequency the 555s are oscillating at, and then converts these into pitch and volume data to be fed to the SID audio chip.

[Linus Åkesson] demonstrates the build ably by performing a slow rendition of Amazing Grace. The SID synthesizer chip in the C64 does a passable job emulating a theremin, used here with a modulated pulse wave sound. It’s an impressive build and one we fully expect to see at a big chiptune show sooner rather than later. We’re almost surprised nobody came out with a C64 Theremin cartridge back in the day.

We’ve seen other fancy theremin-inspired builds recently too, like this light-based design.

Continue reading “C64 Turned Theremin With A Handful Of Parts” →