MixSID Dual SID Board

While me and couple of hundred other SID fanatics are waiting for the SIDFX units to arrive, a new advanced dual SID board design appeared out of the blue; MixSID by Henning Bekel.

The arrival of MixSID is quite interesting, as feature-wise MixSID appears to be on-par with the SIDFX. Want to install any two SID models to any C64 model? Be able to switch between the installed SIDs on the fly? Choose between mono, dual-mono or true stereo operating modes? Have flexible selection for the second SID address space? Adjustable digi-boost for 8580? Volume level balancing for the installed chips? Reduced noise?

Check.

Both SIDFX and MixSID are capable with the above, and more. Of course SIDFX has even more some interesting features, including software configuration for the settings, and automatic configuration (voltage, filters) for the installed chips etc.

Comparing the two is not exactly the point of this article, but I can’t help myself doing that spec-wise, as both are advanced dual SID boards, with many similar features, and appearing around the same time.

The biggest difference between the two is actually the approach and design philosophy; SIDFX states being a plug and play, solder free solution that automatically detects the installed SID chips and configures itself accordingly. MixSID, in turn, is manually configured, comprehensively documented, open source, and DIY-friendly.

In fact, you can only have MixSID by building one yourself. You can go ahead and order or make your own pcbs, but Henning also sells the MixSID boards as kits, and I was sure to get myself one.

SwinSID Ultimate

I’ve written about the need and importance of having a proper replacement for the SID sound chip few times before. So I won’t repeat myself on that, as this is going to be a lengthy article anyway.

Because what we have here is big news on this front.

A duo from Hungary, Máté “CodeKiller” Sebők and Mihály “Hermit” Horváth have been working on improving SwinSID, originally developed by Swinkels.

What they have come up with is a highly modified and expanded version of the Nano SwinSID, now called SwinSID Ultimate. The enhanced hardware is mostly developed by CodeKiller, and Hermit has rewritten a new sound engine almost from scratch. The aim has been to make a more compatible, more capable SID replacement than what the Nano SwinSID already was.

At least the list of improvements is impressive:

SwinSID Evolution

Since it’s initial release in 2010, the Micro SwinSID from Swinkels has gone through some improvements over the years. These improvements have come in form of both hardware and firmware updates.

Most obvious improvement was the change of form factor from the Micro SwinSID to the more familiar Nano SwinSID. Initially the Micro SwinSID was based on DIL-packaged ATmega processor making the board that housed also a full-size crystal oscillator and couple of trough-hole components almost twice as wide as the SID socket. Some time later a redesign appeared that was based on surface mount components, squeezing all the same components into a small PCB that’s no larger than a real SID chip. Or at least as long as only area is considered. Pin headers, components and jumpers make the board somewhat thicker.

Micro SwinSID and Nano SwinSID side by side. Both designs have the same components and features, except for the additional filter jumper in Nano.

During the first few years since the introduction, there was couple of official firmware updates. These firmware updates improved the sound emulation and compatibility with the behavior of a real SID chip, reducing the number of cases where Nano SwinSID would not sound or act ‘right’. Down the line there was also a feature update that made it possible to select the filter emulation between 8580 or 6581-like behavior using a jumper.

These refinements have improved Nano SwinSID, making it more feasible SID replacement with each improvement. Sadly there hasn’t been a new official, or publicly available firmware for the Nano SwinSID since 2012. As if SwinSID had reached its maximum potential with some of its flaws to remain.

This changed in 2014 when Máté ‘CodeKiller’ Sebők stepped up with a new firmware.

Graphics with old C64 colors and how to view them

Continuing presenting some of the graphics I’ve done for the Commodore 64, this article revolves around my latest picture and how to view it – in technical sense.

This picture is a bit different, since it’s made for old PAL C64 with so called “old lumas”, which I covered in my previous post. In other words I’m making use of the slightly different color palette found in early C64s. And not only the palette, I’m also exploiting the color bleeding introduced by the PAL color encoding. The result is that the picture appears to be more colorful than one might expect from the 16-color palette of a C64.

This picture requires a specific hardware setup. Namely a PAL C64 with early 6569R1 VIC-II chip. A real C64 is needed, or alternatively, an emulator or viewer that can simulate the effect of PAL color encoding/decoding while supporting the old lumas. The reason is that with this picture I’m exploiting color bleeding together with the different color palette.

Screenshot taken using an emulator with old luma settings and PAL video encoding emulation.

 

Work process

Working on this piece started on Excel. I wanted to have a proper palette for the old luma colors, so I ran the same calculations that Philip “Pepto” Timmermann has made, but using the old luminance values. This way I got an old luma version of the so called pepto palette. A link to palette at the end of the post.

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:

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!

C64 Kickstarter Cases – With pictures!

The Kickstarter campaign for new C64 C cases using the original molds happened, and a lot of people have been very excited about that. Despite some ridiculous occurrences by Kickstarter (can’t show renders of the cases) and dimwits owning some rights to Commodore brand (can’t even mention Commodore in the campaign), the campaign was a real funding success.

Also the production phase faced an unfortunate incident, as the plastic molding company that produced the cases suffered a fire in the factory. The fire destroyed the transparent cases which had been the first ones pressed. Despite these shortcomings and delays the cases got pressed and sent out in the last couple of weeks. Related forums and social media groups have been filled with photos of these new cases and nice C64 setups installed in them.

I got mine last week, and guess what I’m going to do? Post some pictures of course! 

C64 Reloaded – first impressions

I mentioned about C64 Reloaded in my previous post. Let’s talk a bit more about it.

Because here it is!

The C64 Reloaded is a new C64 motherboard. It is recreated according to the schematics of C64B3 model, ASSY NO 250466, and is designed to use the original C64 chipset. A good description you’ll find on the announcement on Individual Computers’ website. Basically, it’s a real Commodore 64, only manufactured with today’s standards.

I haven’t had enough time to spend with this machine to call this a review yet. Instead I’ll share a pictorial overview of the board and some of the nice details on it.

How about newly produced C64s?

Long time no posting. Once again there’s some interesting things going on in the C64 community. Especially one of the on-going funding campaigns I would like to bring to your attention.

First a quick recap.

C64 Reloaded. Image (c) Individual Computers

Already last year on April Fool’s Day Individual Computers announced the C64 Reloaded. Being no joke, it’s a newly produced C64 motherboard using the original chipset to celebrate C64’s 32th anniversary. After some changes in pricing and availability schedule, these new motherboards should be available on Individual Computers’ web shop shortly.

New C64 C cases. Render (c) Thomas Koch

More recently, on March 2015 an interesting Kickstarter project surfaced. It was for newly produced C64 C casings using the original molds. The project has an interesting back story, and the project funding goal of $ 10,000 was met in no less than a day! Eventually, the Kicstarter for the new colored and transparent C64 cases was so popular, that the initial funding goal was filled almost ten-fold. The cases are in production at the moment, and backers should receive their rewards sometime soon.

As to complete the lineup, there is now another crowd funding project going on for new C64 key caps in various colors. The funding goal is quite high, € 25,000. This is no wonder, as this time also the molds for the casting process has to be made. At the time of writing, roughly 60 % of the funding has been met, and the funding period will last for one and half weeks still, ending somewhere around 28th May 2015.

The C64 Reloaded and new C64 casings already came true. I’m hoping that also this third re-manufacturing project becomes reality. Not only hoping, I’m of course backing also on this effort, and I would like to encourage you to do so too!

SwinSID analog controller hack

I’ve covered SwinSID micro and nano few times before. It’s a great idea – a micro controller based SID chip replacement, working as a spare part  for a C64 or C128, or as a substitute to some other application like a DIY-synth. For Commodores, it’s especially suited for a gaming machine, as only very few games feature such tricks that would not sound about right on the SwinSID.

However, there’s this downside with the SwinSID that it does not support analog controllers. This is because it’s the SID chip that handles the reading of analog controllers in the C64, and the A/D converters are not implemented in the SwinSID. The number of games supporting paddles, mice or analog joysticks is not that big, but still it’s a shame that they won’t work with SwinSID. Also the few games that support second joystick button are affected. They behave as if the second button would be triggered constantly.

So there is a lack of fully featured replacement for a SID chip. This is a shame as SID chips are sought after, and supply for good and working chips is getting more and more scarce. The demand of SID chips have been recognized, as it’s not that difficult to find a supply of SID chips from Asia. It’s just that many have found out that these chips are often dead, faulty or downright fakes, and often rebadged.

Knowing that there are a lot of these faulty SID chips with bad filters or missing sound channels, it had occurred to me that maybe these could be combined together with SwinSID to make at least a fully featured replacement for the SID chip. Sound from the SwinSID, and A/D converters from an otherwise faulty SID.

Recently I ordered some spare parts from Mutant Caterpillar Games, who have a selection of chips for 8-bit computers in stock, including SID chips. As we were talking together with Ian Gledhill about SID sourcing challenges among other things I mentioned this idea of mine. He kindly sent me few faulty rebadged SID chips to test it out.

So, off I am to build an adapter that allows me to install SwinSID and a ‘badSID’ to the C64.