Old VIC-II Colors and Color Blending

Early VIC-II chips produced somewhat different colors than the later ones. In the earliest revisions the 16 colors had five luminance levels, i.e. brightness values. Black and white are the lowest and highest values, and the remaining 14 colors use three luminance levels that are evenly spaced in the brightness spectrum. Simply put, there are dark grey, medium grey and light grey, and all the colors are as bright or dark as these three shades of grey.

In later VIC-II revisions four intermediate luminance levels were introduced. Now there was nine luminance levels instead of the previous five. The palette with nine luminance levels is what most people consider as the normal C64 colors. From this article you can read all about C64 luminance levels and colors.

In this picture you can see how the different luminances affect picture that has been made for the “normal” C64 colors:

Commodore 128 motherboard in high resolution

Here’s a high-resolution photo of C128 motherboard for no particular reason:

Click for more pixels

This one has a Scandinavian character set, that’s why the three paper labeled EPROM chips.

One point worthy of note, though; You often find being said that the Commodore 128 has the “new SID”, 8580. That’s not the case however.

How my pixels got into ROM

This time I’m writing about a C64 game and how I got involved with it, rewinding to early 2015.

For my part things got in motion when my Out Run Memories picture got some positive attention at the time of its release. Thanks to that I got in contact with Antonio Savona, who kindly asked me if I could make a loading picture for his game P0 Snake. Antonio had already created the game for the RGCD C64 16KB Cartridge Game Development Competition 2014, and the game ended up winning the competition by a fair margin!

And it’s no surprise. It’s a clever snake game with a twist, with varied levels and gameplay, and an ingenious one-button game mechanics! On top of the solid game design there are some surprising features for a 16k game like a password system and digitized speech samples! I mean, the game fits into 16 kilobytes. And when that game greets you with a speech sample saying “Welcome to P zero Snake” and introduces more samples during the gameplay, it does raise an eyebrow! There’s an interesting article at the game’s development blog about the challenges with the audio and how it was pulled off.

Just take a look. Note the clever references to various classic games:

Thanks to the 16k game’s success and popularity, it was going to have an extended RGCD C64 cartridge release. And for this extended version I got to make the intro screen!

Maniac Mansion bootleg cartridge

Here’s what I made as a 30 year birthday present for a friend of mine. Maniac Mansion cartridge for the Commodore 64!

Of course a cartridge like this never existed back in the day, as the original Manic Mansion released for the C64 was disk only game. It’s only thanks to the crackers, patchers and hardware developers of recent years who we can thank for the possibility to have this much acclaimed and loved game in a C64 cartridge format today.

You’ve probably guessed already that it’s an EasyFlash cartridge in a ‘custom’ Maniac Mansion themed cartridge case. And on the EasyFlash, there is written the excellent EasyFlash-patched Maniac Mansion Mercury by Onslaught. 

Getting familiar with C64 graphics converting tools

Like I told in my previous post I wanted to enter one of the graphics competitions in this year’s Alternative Party. I wanted to make my picture using C64 graphics formats, but I wasn’t planning to pixel the picture in native formats in the first place. Instead, I was planning to draw the picture using modern tools and then convert it! Shocking!

I already had a concept in my mind that I wanted to try out: to combine and use different screen modes for different parts of the picture. Of course it wasn’t possible to actually use different screen modes with the picture, especially with my non-existing programming skills. So the road I had to take was to draw the picture elements separately which I then converted to different graphics modes. The parts would have to be combined, and then finally, converted into final picture.

This gave me a good reason to start checking out the different graphics converting tools.

C64 EasyFlash

New hardware for the C64 appears like it was still a production machine. It’s amazing. This time I’m talking about EasyFlash cartridge. EasyFlash has existed for some time already, and now I got myself one of those.

I bought mine fully assembled from Mike Betz via Lemon64 Forums. These carts are nicely finished with quality case, stickers and all. And of course I peeked inside – the case hides the real quality of the cartridge; Professionally made PCB, all socketed chips and flawless soldering make up these EasyFlash cartridges.

So what’s EasyFlash?

EasyFlash is a Flash memory based programmable cartridge for C64. Basically it works like any original game or software cartridge except that the cartridge binary (data, or cartridge image) can be easily erased and rewritten. And this is done using no other tools than the C64 and software called EasyProg. Any standard (8k & 16k) or Ocean Type 1 (128k & 256k) cartridge image can be written into EasyFlash and it effectively “becomes” that cartridge.

New DualSID boards

SID-goodness just keeps on coming. Some while ago Tomi Malinen released his DualSID twin-SID PCB. Depending on how the board is assembled and configured you can add either SID model to any C64 model. Additionally, the second SID address can be configured using jumpers. With DualSID board you can have both SID models in one C64 or configure yourself a stereo SID setup for any twin SID application. Anything goes. It’s probably the best and most versatile PCB design so far for adding another SID chip into C64.

I ordered myself few kits already a good while ago, but I have been lazy with my C64 activities lately and have not yet assembled them. I will have to come back to this topic once I have assembled and installed one.

Meanwhile if you’re interested for such board get familiar with the DualSID web site.

Here’s a picture of the kits I ordered:

Three DualSID boards and components for one 6581 and one 8580 model. While the board is the same there are different ways to assemble it depending on which SID model you are going to have as the second one. The FAQ on the site will help to understand the possibilities, limitations and why there are two different ways to assemble the boards.

Also, HVSC update 54 is out!

Micro SwinSID – an AVR based SID replacement

SIDs are sought after sound chips. Being semi-analog they are difficult to emulate. They also break easily from e.g. static discharges. If one is to build a SID synth or you need to replace broken SID chip you may have trouble finding the chips.

SwinSID is a project that I have been keeping an eye on for many years now. Swinkels, the man behind the project, has been prototyping and developing a SID compatible custom sound card for C64 or other SID-utilizing devices such as MIDIbox SID.

Originally the SwinSID was not aiming to emulate a real SID chip but rather to be a pin-compatible SID-like sound device with some enhancements. The hardware is based on one or two (stereo) Atmel AVR microcontollers and some additional circuitry including a DAC.

But now Swinkels and Crisp have developed a new model of a different goal. It is called SwinSID88, or Micro SwinSID, and it’s a direct replacement for the SID chip. It is mono only and it aims to emulate the sound of 8580 SID chip as good as possible.

Tips for using sd2iec

It’s been already a while since I got the uIEC – one of the available hardware running the sd2iec firmware. I did some experimenting with it on how to make the best use of it if the nicely accompanying JiffyDOS is not present. I posted my experiences at Lemon64 forums, but I thought it would be nice to share them here as well. Still, you might want to read that instead for shorter, less detailed description.

Note that I’m describing sd2iec-firmware being used on uIEC/SD-hardware with Commodore 64. Many different hardware combinations are possible.

The principle

With sd2iec loading files from the SD card’s root folder is like loading files from a floppy disk. The very basic loading procedure is exactly the same – except that the default device number is not 8 but 10. So LOAD”$”,10 or LOAD”GAME”,10,1 works just like one would expect.

Things get more complicated if you want anything more. Something like to enter a directory on the SD card or to mount a .d64 disk image. A real Commodore disk drive wasn’t designed for such things so you don’t even have the commands for something like that. Since uIEC is connected only to the serial port of C64 it can be interfaced only using the IEC bus. Enter the command channel! Everything like directory navigation, disk image mounting and device configuration is done by sending drive commands over the command channel.

C64 twenty years after

This summer was my 20th anniversary of owning a Commodore 64. Yes – I got mine when it was already the dusk of C64’s commercial life. But still for many years to come it was the most popular gaming machine among my friends. But why do I still play around with mine? What it gives you in 2010? Of course a great deal of my C64 hobby is nostalgia. But there’s more.

After I had moved away from using the C64 in favour to then-modern PC, I found my interest to the good old Commodore in late 90’s when I found some demos on a BBS and ran them on a C64 emulator. I wasn’t expecting that the C64 could run such effects that could be seen in e.g. Smash Designs’ Triage demos. I was amazed and I wanted to be able to run the most amazing demos I could find on a real machine as the emulation was far from perfect by the time. At this point I had few different models of C64s and I was transferring floppy images to 5,25″ DD floppies with Star Commander.