VChar64 v0.0.5 released

logo512I’ve just released VChar64 v0.0.5.



  • Max tile size is 8×8 (previous was 5×5)
  • Right click works as paiting with background color
  • Fixed compiler warnings
  • Better name suggestions when saving and exporting files
  • Added support for importing CharPad 2.0 files
  • If chars were modified, it asks before quitting and before starting a new one
  • Added icon
  • Added option to load lowercase chars
  • Cue in dialog if chars were modified

C64 SDKBOX intro at Casual Connect 2015 SF

I did a quick’n’dirty intro for the C64 to promote SDKBOX at Casual Connect 2015 SF.

I took the scroller+rasterbar effects from the game that I’m doing, I took the music from somewhere, the fonts from somewhere, I added some simple moving bars at the top… and done. I only had one day to do it, and I was very happy with the result.

The demo ran during the 1st day of the conference on a NTSC C64-SX.


Download the source code from here. Download the binary from here.

Impressions of Google I/O 2015

What was interesting about the Keynote:

  • Brillo: the OS for the IoT… but but but, there were no talks about it, almost no information about it, nothing.
  • Android Studio with C++ support: Finally 🙂 The NDK really needs love, and having an IDE that supports it is great. Hey, even Microsoft is supporting the NDK now in VS2015.
  • Photos is decoupled from Google+ with free unlimited storage: This is great. I’ve been using Picasa since day one and I never used Google+ to store my photos. So basically Photos is the same as Picasa, but with unlimited storage.
  • Offline maps: Yeah
  • Chrome Custom Tabs: Interesting alternative to present 3rd party views with the benefits of both the web and native worlds.

What was not-that-interesting about the Keynote:

  • The rest.

I don’t care if Android has better permissions or not (yeah, the old permissions-model sucked, but I don’t find that news interesting). The Family section for Google Play is good, but not interesting. Android Pay, meh. etc.

One thing that I liked, but was not announced on the Keynote, was Project Jacquard. They are using conductive threads and other stuff to create “smart” cloths. Something that Adafruit and Sparkfun have been doing for a while, BTW.

Continue reading “Impressions of Google I/O 2015”

Soldering, what could go wrong?

I’m good at software engineering, but in electronics, I’m a newbie. Nonetheless, I find electronics fascinating.

Last year I did the first basic tutorials with Arduino, then I played a little bit with Raspberry Pi and CI20 (technically not really electronics). And this year, I built a very simple circuit to connect the RGBI output of my Commodore 128 to VGA… I have been using breadboard, so no soldering, no PCB, or anything like that.

But yesterday I decided that I wanted to keep learning Arduino, so I tried to do some advanced tutorials, and it required soldering. I had never soldered before, I hadn’t read any soldering tutorial… but what could go wrong? Soldering is easy, right?

Well, everything went wrong… I tried to solder an LCD display but didn’t work, I tried to unsolder it and solder it again, but failed again. In fact, I think I burnt the LCD display. And also I think I broke the tip of the solder.

But on the positive side, I think I did all the possible mistakes that one possible can do when soldering… than means that I learned a lot 🙂

My failed soldering experiment
My failed soldering experiment

Anyway, I’ll keep learning electronics… I’ll keep learning how to solder, but this time I’ll practice with empty PCBs.

Merging my unicycling and development blogs

Who has time to maintain two personal blogs ? It is even difficult to maintain just one. So what I did was to merge my unicycle ( blog into this one (

I divided them in categories:

  • The unicycle blog is using the “unicycle” category.
  • This blog is using the “programming” category

VChar64: character editor for the Commodore 64

c64logoI started to code a unicycle game for the Commodore 64. The first thing that I realized was that I needed an game editor, so I started to code one: VChar64.

Today I released v0.0.1 which has basic functionality but the functionality that it has, just work. You can download it from here:


  • Imports raw, PRG and CharPad file formats
  • Exports to raw and PRG
  • Basic editing functionality: Rotate, Invert, Clear, Shift left/right/up/down
  • Multiplatform: Win, Linux and Mac


Coding for the Commodore 64: What changed in the last 25 years


I stopped developing for the Commodore 64 in 1993. Since then a lot has happened:

Back in late 80’s ~ beginning of 90’s:

  • I did all my coding using the Commodore 128’s MONITOR command
    • That means no text editor, no compiler, no linker. Similar to the command that used to be in DOS
  • Since I didn’t use a text editor, I put all my comments in a notepad (I still have that notepad somewhere)
  • I used the Commodore 128’s SPRDEF as the Sprite editor
  • I used my own character editor called vchar… (later I created a similar one for DOS and Linux)
  • I did some basic graphics using a graphics editor… but I can’t remember which one
  • I didn’t know any other C64 developer, so I did everything kind of isolated
    • My sources of information were Commodore Magazine, Tu Micro Commodore and some books
    • I reversed engineer some games / demos in order to learn tricks
    • I had a 300 bps modem but I didn’t find any good C64 BBS
    • I did some cracks for a local company that was “publishing” (AKA pirating) games. In exchange they were providing me games. To put things into perspective it was impossible (I mean IMPOSSIBLE) to get original games in Argentina back then.
  • I knew some basic tricks like how to use more than 8 sprites, how to open the top and bottom borders, some raster effects… but nothing very advanced.
  • I loaded all my programs / games using the disk drive, which was much faster than the datasette, but still very slow
  • I had a fast-loader cartridge to accelerate the disk drive loading times. It also had a rudimentary MONITOR.
  • Although Argentina was using the PAL-N standard I had a NTSC Commodore 128. In Argentina we also had the Argentinean Commodore, called Drean Commodore, which was a PAL-N machine assembled in Argentina

Continue reading “Coding for the Commodore 64: What changed in the last 25 years”