Unijoysticle 2: modern bluetooth gamepads for retro computers

Announcing Unijoysticle 2:

Use modern Bluetooth controllers (gamepads, mice, smart TV remote controllers) in retro computers like the Commodore 64/128, Atari ST, Amiga and more.

For further info go here: https://retro.moe/unijoysticle2



Tandy 64, and intro for the Tandy 1000 and more

With PVM with released an intro for the Tandy 1000 HX.

The Tandy 1000 HX uses the Intel 8088-2 CPU. Which is a suuuuper slow CPU (slower than the 8086). With all its wait states and its limitations on the video card (no hardware sprites, no charset redefinition) it makes it comparable with a Commodore 64. In fact, for certain things a Commodore 64 if way faster.

Without further ado, this is the Tandy intro:

Source code here: https://github.com/c64scene-ar/tandy64

And we’ve just released another chipdisk, this time with Brazilian music:

Source code: https://github.com/c64scene-ar/chipdisk-brazil_bits


Long time no see: UniJoystiCle for all platforms

I’ve been busy. I still have no spare time to work on my retro projects, but I have a plan. And it can’t fail. I plan to port the UniJoystiCle + The Uni Games to the following platforms:

  • Commodore VIC 20: UniJoystiCle (single joystick) + The Uni Games
  • Commodore PET: UniJoystiCle in expansion port (single joystick) + The Uni Games
  • Commodore 128: UniJoystiCle (same as the C64) + The Uni Games in VCD mode using the Z80 CPU
  • Tandy 1000: UniJoystiCle + The Uni Games (graphics mode 320×200 16 colors)
  • Commodore 64: Add paddle support to the UniJoystiCle

Continue reading “Long time no see: UniJoystiCle for all platforms”

Commodore 64 Assembly Tutorial

A few months ago we released the Argentine Songbook Vol. 1 chipdisk. And recently we released its source code including:

  • Full source code (the assembly files + makefiles + everything…)
  • Full audio sources (the SidWizard files)

And we also wrote a tutorial about how write a chipdisk, including all the tricks that we used.

If you have doubts/questions about it, let us know!

CommVEx XII and VCF West XI recap

Two weeks ago I attended the Commodore Vegas Expo XII, and last week I’ve been at the Vintage Computer Festival West XI.


As the name describes it, it was a Commodore Expo in Las Vegas. But the format is a mix between conference and expo. It is a real expo, but with the social part of a conference. It is friendly and casual.

People give talks in a very informal way. I gave a talk + live demo about the UniJoystiCle. Everything went well except that in the middle of the demo my phone’s glass broke. But that wasn’t an issue since the accelerometer kept working.

Doing the UniJoystiCle demo

Continue reading “CommVEx XII and VCF West XI recap”

Finally, a Drean Commodore 64c

As a kid, I always avoided the Drean Commodore. I didn’t like them because they were not compatible with the NTSC software.

As an adult, I really wanted one basically because I’m from Argentina, and the Drean was produced in Argentina. And I want to make sure that all the software that I develop works on a Drean.

And in my lastest trip to Argentina I was able to get one 🙂 The condition of the computer is Ok, neither great nor terrible. It works, although I need to do more tests. Here are some photos:

Playing Popeye. Sound and video work Ok.
Without the cover

Continue reading “Finally, a Drean Commodore 64c”

Fixing the Commodore SX-64: Replacing the MOS 6526

MOS 6526: The CIA chip

You turn on your beloved SX-64 and you don’t see the blinking cursor. Don’t panic. Most probably one of the CIA chips (MOS 6526) is not working correctly.

No blinking cursor

The Commodore 64 has two CIA chips. What you need to do is to replace the one that controls the keyboard, the CIA 1. But if you don’t know which one is CIA 1 and which is CIA 2, then you can either replace both, or do trial-and-error, or look at the IO schematics (hint: it is the one with the UB3 legend).

As far as I know any MOS 6526 should work:

  • MOS 6526 (found in the very first C64s)
  • MOS 6526 R4 (found in newer C64s)
  • MOS 6526A (the 2Mhz version, and I read somewhere that it works Ok)

So, in order to get the replacement chip, you can get it on eBay, or extract it from another another C64 or SX-64. The MOS 6526 chips on a regular C64, are located at the top-left corner.

I removed the 6526 from a regular C64

I suggest using a chip extractor to extract the chips, although a flat screwdriver can work as well.

Continue reading “Fixing the Commodore SX-64: Replacing the MOS 6526”