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Comparing ARMSID and real 6581 SID

I've set up a YouTube channel for posting my music, mostly to give myself an incentive to keep writing and hopefully improve those skills.

I recently posted a version of this eastern-sounding piece rendered by the notation software. An exercise in using the pentatonic minor for that eastern flavour.

I've now made recordings of the C64 playing the piece. First of all I made a 3-voice version (not yet posted) and then an 8-voice version using multi-tracking.

That's the first version you hear in this video, played on my 'bionic 64' which is fitted with an ARMSID.

Curious about how this would compare with the same music played by a real 6581 SID, I did the same recording using an all-original 64 and made a video with one recording after the other. My observations are below but judge for yourself.

In the 'pure' tones it's hard to hear a difference. But there is definitely a difference when there are many voices playing together and using pulse-wave modulatio…
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Homebrew game for C64 - part something.

Progress has been slow, I've been caught up in ironing out a few problems. Debugging those was tiresome, which meant that I found it easy to do other things instead.

But now we have smooth scrolling background, music, enemies that scroll in from the left at an angle (hopefully soon multiple enemies / collectibles) multiplexing sprites (the sheep are each made of two sprites, a multicolour and a hi-res outline overlaid. The clouds are also sprites).

The bionic 64 project

Once I'd started writing a game for the C64 and started playing some of the great new games available, I decided that I needed a 64 that I can switch on and use as much as I like without worrying about stressing 35-year-old components (at least one of which is destined to fail in time).

Emulation is fine, in fact when I'm spending a lot of time playing one game I like to use all of the mod cons; big chair, big screen, Duoshock controller and VICE which makes loading up and saving the game at any point a breeze.

That's not the same as switching on a 'real' 8-bit computer and playing a game from the time.

I had a 'black screen' C64 and so there was an opportunity with a few options. Fit the original case / keyboard with a Pi, or with one of the modern boards - Ultimate 64 or C64 Reloaded

These boards are new boards which emulate the original components. So we're still talking emulation, albeit hardware rather than software. In the case of the Reloaded, y…

Homebrew game for C64 part 7 - revival

Revival of the project, that is. It's not a resurrection-based game.

Following a hiatus due to realising that my original concept was rubbish, I had a different idea. It's nothing particularly original; sideways scrolling, and the sheep following one another like a snake. There will be things to collect, and things to avoid.

Avoiding the enemies will be more difficult, the more sheep are following the one you're controlling. The idea is that you start with one, and accumulate friends as you go along.  They may be dispatched by enemies, and there will be a maximum of four because of the way I've used two sprites to get hi-res with multicolour effect.

There are no collectibles or enemies yet, but here's the basic action, which I'm really happy with.

The sound you hear on the video is being played by a breadbin 64. It's my most recent tune for this game. The video is captured from VICE

It was my first go with the 64's scrolling capability. I cut my teeth o…

Another silly 'walk in the park' tune, rendered on a C64

I'm finding it much easier to write silly tunes for my game than I am to write an actual game for my game.

(see the last post to see how far that's got and why it ground to a halt.)

But I like composing and I'm getting my coding kicks from writing the assembly code to play the music  and developing my own app to convert the notation (via musicXML) into the data for my C64 music routine. It's doing repeats now, as you can see.

The music you hear in this video is being played by a genuine breadbin C64. Thanks SID.

Homebrew game for C64 part 6 - hiatus

Progress with this project ground to a halt for two reasons; I found that I really enjoyed writing the music and have been doing a lot of that, and because when I got to the point where my characters were moving around, I realised that my original concept was rubbish.

At first I'd seen a cross between Lemmings and Pacman - where the sheep would flock and also follow the character that you control. The idea was to try and lead them around obstacles and solve puzzles.
After a break I had the idea of being able to switch character. Each has a name and a 'special skill' and you work out how to use the characters to solve the puzzle.

The mechanics of that are kinda working, as you can see. It needs more characters, the ones that are there need more work. But most of all it needs some time spending designing some devious puzzles for this scenario.

I'll probably take a break and write more music, and let this stew for a bit.

Battery removal - BBC Master

Earlier in the week I commented on Twitter that I was grateful to someone for mentioning that the Master contains a battery, because I didn't think anything I had in the attic had a battery inside. Well now I feel silly:
 There it is.
 Looks like we may have got away with it! There is leakage but it appears to be contained.
 Shall I call Acorn and ask what part they would approve?
 After a rudimentary clean, it's looking very nice indeed. The cartridge contains Wordwise Plus, as the f-key strip hints:

I think I've been lucky not to have had to deal with alkali spills. But the computer is well-designed, even if any had got out, it would have been contained within the plastic of the case as long as the thing is stored at a reasonable angle.

This job is essential when there are potentially 30-year-old batteries in there. It's important not to just replace the old pack with alkaline batteries, because the Master tries to charge them when switched on. The pack should includ…