Tuesday, October 18, 2016

Saturday, October 15, 2016


A while ago I posted about Blu, my blue C64C. I made most of the SID comparison recordings with its 2 SID setup and, because the SID is a fragile chip I wanted to have something that would protect its circuits.

I asked my good friend Hermit (he is one of the developers of the new SwinSID Ultimate) if he's got an idea how I can do it. He took the question very serious and designed a circuit:

Let me copy-paste his words from CSDB, where the official release have happened:

"I designed this simple SID-protector some months ago as Vincenzo needed some protection for SIDs to record safely. I tested the circuit in ngspice (SPICE circuit simulator linux implementation), and Vincenzo built and tested it on real hardware. He didn't try to stress-test it for obvious reasons (too many SIDs died already in C64 history), but the circuit simulation shows that this simple circuit protects SID's output from overvoltages and reverse voltages/currents. If the diodes are of Schottky type (with enough reverse breakdown voltage for the task), the circuit can have less impact on the output signal due to the series diode and more protection in the negative voltage region on SID-output. 50V and more breakdown voltage diodes are preferred because in practice phantom power around 48V is the biggest that a mixer or other devices can drive to the C64 output by accident. 
If the diodes are normal-type (e.g. 1N4148), then D2 in parallel with the Zener doesn't do much and can be left off...
The circuit only worsk with DC output of the SID (or maybe the transistor current amplifier output) and provides DC output which should be filtered with a series capacitor to remove the DC component of the signal or connected to the transistor current amplifier in the C64. The latter hasn't been tested yet, Vincenzo simply used RCA sockets to directly drive the outputs out from the C64... That worked with both 8580 and 6581 SIDs despite the 6581 having incomplete (non-complementer) output...
We hope this can prevent some further SID-deaths for people who try it...

The only difference to the schematics is that I've used 1N4148 instead of Schottky diodes.
After testing this circuit I experienced a bit of volume-loss on the output level, but basically that's it. It worked so far without any further complications and it's small enough to fit inside the C64.

ps: in case you were wondering who is that Vincenzo guy Hermit' mentioned, FYI it's me, vincenzo /StrayBoom Music. composer, sound designer and owner of this blog.


Today's audio-visual experience: Offscreen Colonies by Conspiracy

Wednesday, October 5, 2016

C64 C - new look with old board

Ever wondered how to identify the inside of a C64 by just looking at it from the outside?
I can highly recommend Ilesj's article to start with because it gives you nice examples with photos and explains the differences well.

I recently get my hands on a C64 C, it looks nice from outside, has just slight yellowing. Keys are stiff, on/off switch isn't lose so I was sure it will just simply work when turned on.

Oh yeah, it did! Nice red LED, old-style keys, C64 C is written on the back. I quickly loaded my favorite test track (Jammer - Club Style) to hear how the SID sings.

I immediately realized it's a 6581 because of the filtered sounds and the fact the track is kinda broken. I also made a guess that it's a 6581 R4.

Hint: read my previous articles about comparing different SID revisions, search for "C64 SID shootout" in this blog. Cheers.

Opened the case, removed the shiny alu-cover aaaaaand...!

It's an "old" board, Assy No. 250466. Youngest of the old boards. And have a closer look on the SID:

It's a 6581 R4AR aka. R4 Advanced Resonance. My guess was close enough, right?


Today's music: BitJam Podcast #195 - Manifesto - Dane's Mix From X2014

Saturday, October 1, 2016

Back from holidays with a new post

After a very exciting but also exhausting summer time the Kompjut0r blog returns with new posts. I had the chance to take a photo of my current collection and would like to share it. I'm not going to fight for "The Biggest Obsolete Computer Collection" title, it's just a bit of bragging about my stuff because I'm proud of it.

Most of them are in good condition just need cleaning inside and out, but still need to test a few of the C64's since they are newcomers and I never switched them on.

ps: I'm looking for a bigger flat and a huge shelf to store all this stuff


Today's music: Surprise, just click and pump up the volume

Tuesday, July 5, 2016

C64 repaint

After a few weeks of silence - pun intended, the previous posts were about music - I'm back with a completely different topic of renovating retro computers.

I've posted a few pictures about a C64 C months ago in this post: C64 C - I'm blue, I'm blue!
Since then I made progress with renovating the scratched case and decided to try out something new: repaint and make it unique.

Started with a warm bubble bath - no, not me, I washed the plastic case in a warm, soapy bubble bath then let it dry out. Some very fine sandpaper helped to soften the scratches, tho it wasn't enough to completely remove them. Well, my patience was over as well, so I went online to check available spray paints.

Went with a very simple grey colored spray can, he only criteria was to be able to paint plastic with it. The whole C64 case was a wreck already so I had nothing to lose - I thought.

Bubble bath followed the sandpapering session, had to clean it before painting. Then, two layers of spray painting has been applied, including 2 days of drying between the 2 layers.

After the second layer of grey paint I left it on the balcony, fortunately there was no rain, only calm wind that helped with drying.

Grey base. Well, looks better than the original, scratchy surface but it's still not enough. What to do, what to do..? Add colors! And add some well-known game characters.

It seemed to be a great idea but wasn't easy to realize it. It's not easy to draw without any talent... Anyway, I had to try it.

And failed. So I repainted the whole thing with grey again.

And then asked my wife if she wants to help me with drawing and she did offer her help! I'm a lucky man.

We chose a few classic games like Bruce Lee, Pacman, Space Invaders, Inter Karate and printed the characters on an A4 paper (thanks to Poison for helping with setting up the proper size).

It took a few hours to properly draw and fill the characters but I think it worth the effort.
They looked really cool but overall, it was just a few black characters on a grey plastic so we decided to fill 'em up with some colors.

Looks a bit abstract, right? Yeah, it's not _that_ great as I had it in my vision but it's still looking good and what's important: it's unique and it's the first one. The next one will be better, because I won't stop here. You've been warned.


Today's music: BRUCE LEE (1984) - LukHash REMIX (performed by Kung Foo Panda)

Tuesday, May 10, 2016

C64 SID Shootout part 5. - SID 6581 vs. SwinSID Ultimate (in 6581 mode)

It seemed to be a good idea to give another round to the SwinSID Ultimate because, did you know it has 6581 mode as well? Yeah, this little gem is capable of emulating both 6581 and 8581 revisions. However, its main mode is 8580 - as CodeKiller explained it to me.
Also, 6581 mode is not complete yet as there were not enough memory to emulate filter distortion and some other bits as well. Let's see (hear) how accurate is SwinSID Ultimate's (SSU from now on) 6581 emulation.

Nope, I won't normalize the recorded audio files. Yes, I know the loudness level is different on 6581 and SSU. Still, in my opinion the true comparison is WhatYouSeeIsWhatYouHearWithoutAnyModificationHearingTrueOutput. That's it. You have volume control on your audio equipment, use it to compensate loudness diferences.

The following lines needed to switch the SSU to 6581 mode:
POKE 54272+29,ASC("S")
POKE 54272+30,ASC("E")
POKE 54272+31,ASC("6")
Reset C64.

To switch back to 8580 mode just simply write "8" instead of "6" into the third line. It's quite simple, isn't it?

I used Breadbin with the most loved SID 6581, the 1485 so the expectation for SSU is VERY high. Ladies and gentlemen, make your bets. Based on previous tests, what do you think? How SSU can meet the expectation?

Ready? 3... 2... 1...

Chris Hülsbeck - Hollywood Poker Pro main - SID 6581 1485

Good ol' Hollywood Poker with the dance animation scene..! (and more but that doesn't matter right now)

Chris Hülsbeck - Hollywood Poker Pro main - SwinSID Ultimate - 6581 mode

I'm going to repeat myself: impressive! The original SID is a bit brighter and the filter seems a bit more opened but SSU is great as well. Sounds like differences between 6581 revisions.

MSK - Land Of Illusion - 6581 1485

It's a multispeed track. I didn't dig into the code to check it but it's clearly audible, especially on some arpeggiated notes. Nice track, nice sound trickery.

MSK - Land Of Illusion - SwinSID Ultimate - 6581 mode

Wow, nice. Flawless multispeed reproduction, the only noticeable difference is the filter. Again, it's a minor thing, SSU's filter doesn't have distortion and it seems a bit more closed or deeper.

Drax - Drudgery - 6581 1485

This track is something special. Not just because it's beautiful and the bassline is extraordinary, but it also has nice filter variations between bass and arpeggios.

Drax - Drudgery - SwinSID Ultimate - 6581 mode

SSU did it again, same result as before: waveforms reproduced well, filter is a bit different but has that mojo. Actually, I like the deeper filter in this track more than in the 1485 version.

Jeff - Blowing - 6581 1485

This. Is. One. Of. The. Best. C64. Tracks. Ever. (personal taste of course, don't take it too seriously) Perfect dance music, awesome sounds, great melodies.

Jeff - Blowing - SwinSID Ultimate - 6581 mode

Again, question of taste matters. Which one do you prefer? The original with a bit more opened filter or SSU that is a bit deeper-boomier?

And now, here comes my favorite 6581-breaker - that is actually a music written on a 8580 SID. Guess how SSU delivers a 8580 track in 6581 mode. Will it break as it would on a real 6581? Or will it play perfectly, because this is an emulation?

Jammer - Club Stylier - SwinSID Ultimate - 6581 mode

Aaaaawyeah, it breaks as it should! :) Honestly, I expected it would play nicely but it didn't. It makes sense, SSU is switched to 6581 mode and a real 6581 breaks this track, so SSU did it as well.


I wanted to write something nice as conclusion but I realized it's not necessary. The SwinSID Ultimate is the current best SID alternative if you want to replace your broken SID in the real C64. It doesn't matter which revision you prefer, SSU's performance is outstanding either in 6581 or 8580 mode.

Tuesday, April 26, 2016

C64 SID Shootout part 4. - SID 8580 vs. SwinSID Ultimate

Page has been updated with a nice music player, shouldn't any playback issue appear anymore \o/

. .. ... .... ....... .... ... .. .

Had some time to make another comparison! This time I compared a 8580 (2288) to the very new, only prototype shaped SwinSID Ultimate.
Don't let it fool you, it doesn't look nice yet but who cares if the sound is great, right? I don't. The audio quality, replay and features are more important than the look.

It's sitting in a C64 E (469 REV B) board and is happy there. I'm thinking of keeping it there forever, first because it fits very tight and is tricky to insert/remove without hurting the legs. And then because I like the sound much so why should I remove it?

I don't really want to write about technical details and stuff, you can read more about it at ilesj.
Do it, read his article because it's great, however, there are no audio examples so I take it as a challenge to be the first to record, compare and release some audio material with the SwinSID U.


I've chose some great demoscene tracks again - and only one game music -, tried to select some tricky tunes with good sound design and musicality to see how the SwinSID U performs in kinda extreme conditions.

Let's start with one of my favorite music that starts with one of the coolest car engine sound effect:

Necropolo - Cadmium - SID 8580 R5 2288

How cool is that sound, right? Necropolo bends the SID like it was his guitar, pushing the limits and making the SID bleed. Now here comes the SwinSID U version:

Necropolo - Cadmium - SwinSID Ultimate

Output volume is definitely lower but I must say, it's impressive how the SwinSID U reproduces the original sound. It's not 100% there but almost reaches it. The 8580 is a bit more beefy but basically that's it, the 2 are identicaly - and don't forget the fact that the SwinSID U is still an emulation

Let's jump to the next track:

David Whittaker - Lazy Jones subtune 1 - SID 8580 R5 2288

Not much to say, it's Lazy Jones. However, due to the special playroutine the previous version of the SwinSID had issues with it until CodeKiller's "lazyfix", and the Ultimate just says, "naah, I can take it":

David Whittaker - Lazy Jones subtune 1 - SwinSID Ultimate

Flawless victory.


Let me interrupt the show with more fancy visualization of audio waveforms. I know, I know, this is my fetish.

The following screenshot is the side-by-side comparison of Cadmium on 8580 (upper) and SwinSID U (lower).

8580 looks a bit more sharp and spikey, SwinSID U is softer - now you can see it, not only hear. However, the waveform reproductions is awesome, it's as close as it can be. Just think about it, the SID is a kinda analog synthesizer and the SwinSID U is a digital replica. Impressive.

Lazy Jones waveform comparison, 8580 upper, SwinSID U lower:

Again, 8580 is a bit louder and sharper. The visual waveform differences are barely audible.


Back to music comparison. How about a heavy metal track, written on a 6581 SID, played on a 8580?

Thomas Danko - Wonderland X intro - SID 8580 R5 2288

Awesome track, great sound design. And btw, great demo, you should watch it.

Thomas Danko - Wonderland X intro - SwinSID Ultimate

Quieter but similar sounding. Another flawless victory.

So far the SwinSID U did the job well, but I want digitized sounds. Ready?

Fanta - Coma Light XIII tune 4 - SID 8580 R5 2288

Funky track, we are Oxy. Clean digisound, no beeps, no cracks, just the clean digisound.

Fanta - Coma Light XIII tune 4 - SwinSID Ultimate

Let's play a game. Find the 10 differences between the original and this one. Send the result via email to me.

And the last track for today is another digitune:

Swallow - Fantasmolytic - SID 8580 R5 2288

This is a remake of Danko's popular demo-loader music, mixed and remixed by Swallow. Hardsync, digi sounds.

Swallow - Fantasmolytic - SwinSID Ultimate

Aaand, SwinSID U. A bit different, carrier signal is audible but it's not bad at all. It's not beeping all the time, only when the samples kick in. Still great, still sounds good.


SwinSID U is a great SID replacement. It's not 100% true to the original sound but I don't think it's even possible. There are many different methods to play - plus digi - music on the C64 that faithful emulation is technically nearly impossible. SwinSID U is softer than the original SID, maybe a bit of waveshaping could help but not really necessary. The audio quality is top notch and it has the mojo.
Well done Hermit and CodeKiller!

Friday, April 22, 2016

Blu - Close to perfection

*I renamed my "Blue" C64 to "Blu". It's better now, right? Right??


It's so wonderful how many options we have to ruin those good old computers. For example, expansion cards, extra RAM, extra CPU, etc. This time I decided to ruin Blu with an additional SID.

It's not really a new method to expand the sound capabilities of a C64 with another SID. DualSID, so called. Use 2 similar SIDs, set them to different memory address and that's it. If the software, for example a music editor supports this, you will have 6 independent SID channels which is great. It means more sounds, more opportunity to create great music on the '64.

The "Pseudio-Stereo SID" by Tynemouth Software is a bit different. The idea was to create a Stereo C64 using 2 SIDs, where the SIDs are set to the same memory address AND they play the same audio output AND they can be either 6581 or 8580 SIDs.

This way the C64 has still 3 channels but they are doubled and have separated audio outputs as well
I ordered my PCB for a C64C (SID 8580) with additional slot for a 6581.

You know me, I like to compare the SID revisions to each other and this would be a great way to listen to some music and record it simultaneously - or just simply compare the audio differences.

So, it has arrived. Nice and clean PCB, well organized and made. I wanted to use RCA connectors as they are easy to connect to any interface or mixer. I decide to drill holes on the left side of the case as there is enough room for them.

One RCA connector for 8580 (right side) and another for 6581 (left side). Maybe they are a bit too close to each other but well, it works fine and is not _that_ ugly.

The 2 best sounding SIDs (in my opinion) were plugged into the slots, 8580 2288 and 6581 1485. This 8580 is significantly louder but that can be compensated on my mixer easily.

I tested it with a 8580 3991 and that was on kinda the same loudness level as the 6581. Conclusion, there _is_ difference between 8580 models as well.

Anyway, I will keep 2288 and 1485 because I like them.

Blu is close to perfection. I still need two things to solve:
  1. Blue keycaps, replacing the original white keys (Kickstarter is over, we are waiting for shipping)
  2. Additional electronics to protect SID outputs (SID output is very sensitive and can break easily)


Today's music: Chiptune Extravaganza @ Revision 2016 demoparty

Saturday, April 16, 2016

SwinSID V2 - aka. SwinSID Ultimate

I received a SwinSID prototype for testing and after a first round I must say, it's impressive. Very impressive. Waveform emulation (simple and mixed), filter emulation, digi music, everything is there. While this specific SwinSID is meant to be the emulation of a 8580 SID it emulates the 6581 really good as well.

Obviously, there are slight differences but overall it's great. Filter is a bit more open than the original 8580's, white noise is a bit softer. It's highly recommended to get one as soon as the developers are ready with the final version.

Day 5. They still suspect nothing.


Today's music: Jammer - Foregone Destruction C64 version

Sunday, April 10, 2016

C64 G - Black screen :(

I got my hands on a C64 G, a nice and beautiful one. Warranty seal was untouched so I had high hopes when I turned it on... then nothing happened.

Ok, that's bad.
I quickly plugged in another PSU and voila, the machine was... almost alive.
Black screen, nothing else.

That means, I had to remove the warranty seal and check what's going on inside the C64.
The memory chips were heating up very quickly, so it seemed obvious they were defective.

Others were fine, no presence of overheating so I thought the solution will be simple.
I started to search for replacement chips and sockets immediately.

Ordered a pack of sockets (sidenote: it's much cheaper if you order 20+ pieces than order only 2...) and finally found XX464 memory chips as well for a good price. So, I removed the defective chips and soldered the sockets.

After memory replacement it still doesn't work :(
Black screen.
So I have to dig deeper and find out what might be the problem.

I even tried to touch the G-spot but didn't help :(


Today's music: X Marks The Spot - 64k Intro by Portal Process