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 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.

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. 

MMC2IEC, a uIEC alternative

Already good while ago I bought this MMC2IEC kit from Retro-Donald together with other junk. Basically it is just one hardware design variant that runs the popular and widely used sd2iec firmware. Just like the uIEC, SD2IEC, C64SD and many other devices. If you randomly come by an SD card drive for 8-bit Commodores, it’s probably some sort of SD2IEC/MMC2IEC variant.

This particular variant of the hardware goes by name Peter Sieg Platine, Peter Sieg plate. It’s Lars P. hardware configuration – which is important information when flashing or updating the AVR firmware. The kit came with ATMega 1284 AVR – a 128k chip that is likely to fit also the upcoming updates of sd2iec firmware in future.

Anyhow, this one was not a complete ready to use device, but a DIY kit that consists of nothing but the board, the SD card slot and an optional preprogrammed AVR chip. The kit with programmed AVR didn’t cost very much, and the remaining electric components were only few euros from a local electrics shop.

Even though this kit is no longer available from Retro-Donald’s Sinchai shop, I’ll go ahead and run down what I did with mine and how I built it. After all, this device is so simple, that it would be fairly easy to build one without any kit. If you have the possibility to make the PCB and program the AVR, plus solder all the parts together, you can basically make this very device from scratch.

The PCB design and layout files are also available in different formats here and on the author’s page.

I’ve got awesome friends!

Just check out these awesome self-made cards I got for my 30th anniversary! Big shout-outs to my dear study- and workmates! I was totally blown away :)

 

 

C64 S-Video cable – the easy way, and with no SCART

I made another C64 S-Video cable for a fellow Commodorist. Instead of using SCART, this time I made the cable as an actual S-Video lead, which admittedly is more universal than the SCART connector. Also this way it doesn’t take that much effort to make the cable.

This time I present you step-by-step instructions on how to make the thing. For more theoretical approach and details about the wirings and components, check the other post where I made the SCART cable.

I think the best and easiest way to make a cable like this is to use an ordinary S-Video and audio leads. And that’s what we’re going to do here.

Here’s what we need. An S-Video lead, an ordinary audio cable with RCA male connectors, an 8-pin DIN plug for the C64 Video port (check the other post for connector type details) and a 330 ohm resistor. Additionally you might need some heat shrinking tube, and of course, a soldering iron plus some solder, and tools for wire stripping and cutting. Not to forget a continuity tester or multimeter.

C64 A/V cable – theory and practice

A while ago I made a proper SCART cable for Amiga, so why not for C64 as well? So what I did was a C64 SCART cable with selectable composite/S-Video mode, including a ‘chroma fix’ and audio noise reduction ‘mod’ plus a preparation for possible stereo audio use. But let’s start with the theory.

Cable making principle

Building an A/V cable for C64 is not very difficult. In the simplest form, what is needed are plug for the C64 Video port, a cable with enough wires for the desired operation and the output connector(s).

C64 Video port

The C64 Video port is an 8-pin DIN connector, which is a standard multi purpose connector. It means that the required DIN plugs are easy to find and cheap. However, there are two different versions of the 8-pin DIN plug. The two versions differ in the shape of the arc that the pins form. Best shown as a picture:

The two pins marked in grey in the wrong type DIN plug will prevent the plug from being inserted into C64 A/V jack. But not to worry in case you’re holding the wrong type of plug in your hand, these two pins can be cut off or pulled out from the connector plug. In any ordinary A/V cable they are not needed anyway. Here is the Video port pinout:

Some early C64s had a 5-pin Video port that are missing the pins 6-8. It means there’s not separate chroma signal available there. In other words: no S-Video, only composite available via the video port.

Make note on the pin 8. It is either directly wired to the +5V DC line from the PSU (after the power switch) or not connected. According to my first hand research, the +5V DC line is present in the C64 Video port in all but the earliest two models. The +5V line is present starting from model C64B, or motherboard ASSY-NO. 250425. That means machines manufactured starting from 1984.

Brilliant picture from Amiga with RGB-SCART

I wanted to be able to hook up an Amiga 500 to TV with decent picture quality for an upcoming gaming session. Instead of using the lousy composhite signal or the dreadful RF antenna cable I wanted something much better because modern TVs don’t forgive low-quality video signal. In fact, flat panel TVs tend to make old systems look really bad. Low resolution and sharp, pixelled graphics (in contrary to e.g. real life video) transferred using blurry and noisy signal, and then displayed stretched and processed on a HD panel. You know it ain’t gonna be pretty! The best way to prevent the worst eyesores is to use high quality video signal at least.

So, off to make a RGB SCART cable for that Amiga.

Stuff from Retro-Donald

Just a quick heads-up, I recently ordered some stuff from Retro-Donald’s Sinchai-Shop. Finally the goods arrived, and above you can see the loot I got.

Top: Micromys V3. Below, from left to right: EasyFlash 3, MMC2IEC + programmed AVR, Nano SwinSID, Super PLA.

Sinchai.de is an online shop that is specializing in Commodore 8 bit accessories and DIY kits. Unfortunately the site is in German only, as is all communication and support. Additionally the information and instructions for the products may be very slight, and most of the product support seems to be at the German C64 forum Forum-64. The shop supports the community there and vice versa it appears.

At least the product assortment is very interesting, and they ship worldwide. And Google Translate is your friend if you are like me and don’t speak nor read German.

Apart from the language barrier and almost three weeks’ delivery time I’m very pleased with the experience. Might be that Donald is busy putting the now-released EasyFlash 3 boards together! The pieces I finally got are of good quality, and the packaging was well done. Postage rates were reasonable, and generally, so are the prices at the shop. My recommendations.

Quick run-down of the stuff I ordered

Sega Saturn DIY Virtua Stick

I like my Sega Saturn. I like the fighting games on it. I like arcade sticks. But I never had the Virtua Stick for the Saturn. So I decided to build one for myself.